bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of Endothelial Dysfunction by Selective Estrogen Receptor-α Stimulation in Ovariectomized SHR
Authors: Widder Julian , Pelzer Theo , von Poser-Klein Christine , Hu Kai , Jazbutyte Virginija , Fritzemeier Karl-Heinrich , Hegele-Hartung Christa , Neyses Ludwig , Bauersachs Johann
Published: October 2003

Both known estrogen receptors, ERα and ERβ, are expressed in blood vessels. To gain further insight into the role of ERα in a functional setting, we investigated the effect of the novel highly selective ERα agonist Cpd1471 on vascular reactivity in ovariectomized spontaneously hypertensive rats (SHR). After ovariectomy or sham operation, 12-week-old female SHR received either 17β-estradiol (E2, 2 μg/kg body wt per day), the selective ERα agonist Cpd1471 (30 μg/kg body wt per day), or placebo. Acetylcholine-induced endothelium-dependent vasorelaxation was significantly blunted in aortas from ovariectomized rats (R
max
, 53%±3% versus sham, 79%±2%;
P
<0.001). Treatment with E2 or Cpd1471 significantly augmented acetylcholine-induced relaxation in ovariectomized rats (R
max
, 70%±2%; resp, 73%±2%). Endothelium-independent relaxation induced by sodium nitroprusside was not different among the four groups. The contractile response induced by the nitric oxide (NO) synthase inhibitor Nω-nitro-
l
-arginine, an index of basal NO formation, was significantly lower in ovariectomized rats compared with sham-operated animals (53±2% versus 77%±5%;
P
<0.01) and was normalized by both E2 (70%±2%) and Cpd1471 (70%±3%). Aortic endothelial NO synthase (eNOS) expression and phosphorylation of the vasodilator-stimulated phosphoprotein, an index of NO/cGMP-signaling, was reduced in ovariectomized SHR and normalized by E2 and Cpd1471. In SHR after ovariectomy, endothelium-dependent NO-mediated vasorelaxation and eNOS expression are attenuated. The novel selective ERα agonist Cpd1471 prevented these pathophysiological changes to a similar extent as E2. Thus, the pharmacological principle of selective ERα activation mediates positive vascular effects.
Ac-SDKP Reverses Cardiac Fibrosis in Rats With Renovascular Hypertension
Authors: Peng Hongmei , Carretero Oscar A. , Brigstock David R. , Oja-Tebbe Nancy , Rhaleb Nour-Eddine
Published: October 2003

N
-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a natural substrate for the N-terminal active site of angiotensin-converting enzyme (ACE). We previously reported that Ac-SDKP prevented cardiac fibrosis in rats with renovascular or aldosterone-salt hypertension. However, it is not clear whether Ac-SDKP reverses cardiac fibrosis in hypertension, nor the mechanism(s) involved. In the present study, we tested the hypothesis that Ac-SDKP reversal of hypertension-induced cardiac fibrosis involves a decrease in transforming growth factor-β (TGF-β) and/or connective tissue growth factor (CTGF). In 2-kidney, 1-clip (2K-1C) hypertensive rats, Ac-SDKP at 400 or 800 μg/kg per day SC was started 8 weeks after hypertension and cardiac fibrosis were established and was continued for 8 weeks. Left ventricular (LV) collagen in rats with 2K-1C plus vehicle at 8 and 16 weeks after clipping was similar but higher than in the sham group (
P
<0.05). Ac-SDKP at 400 and 800 μg/kg per day, which increased plasma Ac-SDKP 2- and 5-fold, respectively, reversed the increase in LV collagen in a dose-dependent manner. The mechanism by which Ac-SDKP reverses LV fibrosis does not appear to depend on ACE inhibition by Ac-SDKP, since we found that Ac-SDKP at various doses did not affect blood pressure responses to exogenous angiotensin I or bradykinin. However, Ac-SDKP reversed the increase in LV TGF-β and CTGF compared with rats with 2K-1C plus vehicle (
P
<0.005). We concluded that in hypertension, Ac-SDKP reverses cardiac fibrosis, perhaps due in part to a decrease in TGF-β and CTGF in the heart.
Adiposity Is Related to Gender Differences in Impaired Stress-Induced Pressure Natriuresis
Authors: Harshfield Gregory A. , Wilson Martha E. , McLeod Kathryn , Hanevold Coral , Kapuku Gaston K. , Mackey Lynne , Gillis Delores , Edmonds Lesley
Published: October 2003

The purpose of this study was to determine if there are gender differences in stress-induced pressure natriuresis and to examine the effects of adiposity on these differences. The subjects were 151 boys and 141 girls 15 to 18 years of age who underwent a 5-hour stress protocol (2-hour prestress, 1-hour stress, 2-hour poststress) after being brought into similar levels of sodium balance. The gender-by-condition interaction was significant for systolic and diastolic blood pressure (
P
=0.001 for both), and the effect of condition was significant for sodium excretion (
P
=0.001). Systolic blood pressure was higher for boys throughout the protocol (
P
=0.001 for each) and correlated with body mass index at each condition (range in
r
=0.28 to 0.35;
P
<0.001 for each). Hemodynamically, in boys body mass index was correlated with cardiac output during stress (
r
=0.23;
P
=0.006), which was correlated with systolic blood pressure (
r
=0.21;
P
=0.01). With respect to natriuresis, body mass index was inversely correlated with sodium excretion during stress (
r
=−0.22;
P
=0.008) and positively correlated with angiotensin II in a subsample of boys (n=89:
r
=0.31;
P
=0.003). The inverse correlation between angiotensin II and sodium excretion during stress approached significance (
r
=−0.17;
P
<0.06). Similar results were not observed for girls. In conclusion, gender differences in stress-induced pressure natriuresis appear to be related to the influence of adiposity on both blood pressure and natriuresis.
Hypertension, Blood Pressure, and Heart Rate Variability
Authors: Schroeder Emily B. , Liao Duanping , Chambless Lloyd E. , Prineas Ronald J. , Evans Gregory W. , Heiss Gerardo
Published: October 2003

Dysregulation of the autonomic nervous system has been implicated in the development of hypertension. Heart rate variability is a noninvasive tool to quantitatively estimate cardiac autonomic activity and has been used to document decreased cardiac autonomic activity in hypertension. The ability of decreased heart rate variability to predict incident hypertension has not been well studied, and there are no studies of whether hypertension leads to changes in heart rate variability. We investigated the temporal sequence linking hypertension, blood pressure, and heart rate variability in a population-based cohort of 11 061 individuals aged 45 to 54 years at baseline. Individuals with hypertension had decreased heart rate variability at baseline, and this association was present across the full blood pressure range. Among 7099 individuals without hypertension at baseline, low heart rate variability predicted greater risk of incident hypertension over 9 years of follow-up. The hazard ratio (95% confidence interval [CI]) for the lowest compared with the highest quartile of the standard deviation of normal-to-normal R-R intervals was 1.24 (95% CI, 1.10–1.40), for the root mean square of successive differences in normal-to-normal R-R intervals was 1.36 (95% CI, 1.21–1.54), and for R-R interval was 1.44 (95% CI, 1.27–1.63). Over 9 years, there was no measurable difference in the rate of change in heart rate variability among those with and without hypertension, although the differences in heart rate variability at follow-up were smaller than those at baseline. These findings thus support the thesis that the autonomic nervous system is involved in the development of hypertension, yet suggest that differences in the autonomic profile of hypertensives and normotensives do not increase with time.
Cardiac Hypertrophy Is Associated With Decreased eNOS Expression in Angiotensin AT
2
Receptor–Deficient Mice
Authors: Brede Marc , Roell Wilhelm , Ritter Oliver , Wiesmann Frank , Jahns Roland , Haase Axel , Fleischmann Bernd K. , Hein Lutz
Published: October 2003

Angiotensin II receptors play an essential role in cardiovascular physiology and disease. The significance of angiotensin type II (AT
2
) receptors in cardiac disease still remains elusive. Thus, we tested in gene-targeted mice whether AT
2
receptors modulate cardiac function and remodeling after experimental myocardial injury. To generate myocardial infarcts of reproducible size, a cryolesion was generated at the free wall of the left ventricle of wild-type mice (
Agtr2+/Y
) and mice carrying a deletion of the AT
2
receptor gene (
Agtr2-/Y
). Postinjury remodeling was followed up for 4 weeks after cryoinjury. The cryoprocedure led to an increased heart weight/body weight ratio and heart weight/tibia length ratio in AT
2
-deficient mice compared with control mice. Morphometric analysis revealed a significant increase in myocyte cross-sectional area after cardiac injury (infarct vs sham
Agtr2+/Y
, +53%; vs
Agtr2-/Y
, +95%). Expression of endothelial nitric oxide synthase (eNOS) was significantly lower in hearts from
Agtr2-/Y
than from
Agtr2+/Y
mice. eNOS downregulation was accompanied by a decrease in cardiac cGMP levels in
Agtr2-/Y
mice. In isolated murine cardiomyocytes, angiotensin II induced eNOS expression through AT
2
receptors, and inhibition of NO production by
N
G
-nitro-
l
-arginine methyl ester abolished the antihypertrophic effect of AT
2
on cardiac myocytes. Our results demonstrate in a genetic mouse model that angiotensin II AT
2
receptors exert an antihypertrophic effect in cardiac remodeling after myocardial cryoinjury and link the expression of cardiac eNOS to AT
2
receptor activation.
Tumor Necrosis Factor–Mediated E2F1 Suppression in Endothelial Cells
Authors: Kishore Raj , Luedemann Corinne , Bord Evelyn , Goukassian David , Losordo Douglas W.
Published: October 2003

After balloon angioplasty, locally expressed tumor necrosis factor (TNF)-α disrupts endothelial cell (EC) proliferation and reendothelialization of the injured vessel. We have previously reported that TNF inhibits the EC cycle and downregulates the transcription factor E2F1. Ectopic expression of E2F1 at the site of injury improves reendothelialization of the injured vessel. In this study, we report that c-Jun N-terminal kinase (JNK) 1 and p38 mitogen-activated protein kinases (MAPKs) are differentially required for E2F1 expression and activity in ECs. Overexpression of constitutively active JNK1 mimicked TNF-mediated inhibitory events, whereas dominant-negative JNK1 prevented these effects. E2F
cis
elements in the promoter of E2F1 gene mediate suppressive actions of TNF, because removal of these sites rendered E2F1 promoter activity insensitive to TNF. JNK1 physically interacted with E2F1 and inactivated it via direct phosphorylation. Additionally, TNF inhibited Rb phosphorylation and dissociation from E2F1. Overexpression of constitutively active p38 MAPK facilitated Rb-E2F1 dissociation, whereas that of dominant-negative p38 MAPK did not. Taken together, these data suggest a differential requirement of JNK1 and p38 MAPK in TNF regulation of E2F1. Targeted inactivation of JNK1 at arterial injury sites may represent a potential therapeutic intervention for ameliorating TNF-mediated EC dysfunction.
Aldosteronism and Peripheral Blood Mononuclear Cell Activation
Authors: Ahokas Robert A. , Warrington Kenneth J. , Gerling Ivan C. , Sun Yao , Wodi Linus A. , Herring Paula A. , Lu Li , Bhattacharya Syamal K. , Postlethwaite Arnold E. , Weber Karl T.
Published: October 2003

Aldosteronism eventuates in a proinflammatory/fibrogenic vascular phenotype of the heart and systemic organs. It remains uncertain whether peripheral blood mononuclear cells (PBMCs) are activated before tissue invasion by monocytes/macrophages and lymphocytes, as is the case for responsible pathogenic mechanisms. Uninephrectomized rats treated for 4 weeks with dietary 1% NaCl and aldosterone (ALDOST, 0.75 μg/h) with or without spironolactone (Spi, 100 mg/kg per daily gavage) were compared with unoperated/untreated and uninephrectomized/salt-treated controls. Before intramural coronary vascular lesions appeared at week 4 of ALDOST, we found (1) a reduction of PBMC cytosolic free [Mg
2+
]
i
, together with intracellular Mg
2+
and Ca
2+
loading, whereas plasma and cardiac tissue Mg
2+
were no different from controls; (2) increased H
2
O
2
production by monocytes and lymphocytes together with upregulated PBMC gene expression of oxidative stress–inducible tyrosine phosphatase and Mn
2+
-superoxide dismutase and the presence of 3-nitrotyrosine in CD4
+
and ED-1–positive inflammatory cells that had invaded intramural coronary arteries; (3) B-cell activation, including transcription of immunoglobulins, intracellular adhesion molecule-1, and CC and CXC chemokines and their receptors; (4) expansion of B lymphocyte subset and myosin heavy chain class II–expressing lymphocytes; and (5) autoreactivity with gene expression for antibodies to acetylcholine receptors and a downregulation of RT-6.2, which is in keeping with cell activation and associated with autoimmunity. Spi cotreatment attenuated the rise in intracellular Ca
2+
, the appearance of oxidative/nitrosative stress in PBMCs and invading inflammatory cells, and alterations in PBMC transcriptome. Thus, aldosteronism is associated with an activation of circulating immune cells induced by iterations in PBMC divalent cations and transduced by oxidative/nitrosative stress. ALDO receptor antagonism modulates this neuroendocrine-immune interface. The full text of this article is available online at http://www.circresaha.org.
Alteration of NMDA NR
1
Receptors Within the Paraventricular Nucleus of Hypothalamus in Rats With Heart Failure
Authors: Li Yi-Fan , Cornish Kurtis G. , Patel Kaushik P.
Published: October 2003

One of the pathophysiological characteristics of chronic heart failure (HF) is elevated sympathetic drive, which is a major factor contributing to the morbidity and mortality of HF. Resent evidence points to a central mechanism that contributes to the sympathetic abnormality in HF. The paraventricular nucleus (PVN) of the hypothalamus is an important site that integrates sympathetic nerve activity. Studies have shown that glutamate elicits excitatory effects on neurons in the PVN through the NMDA receptor. The goal of the present study was to examine the role of NMDA receptors in the altered sympathetic nerve activation during HF. The left coronary ligation-induced heart failure model in the rat was used. In α-chloralose and urethane anesthetized rats, microinjection of NMDA into the PVN (50 to 200 pmol) produced dose-dependent increases in renal sympathetic nerve discharge (RSND), arterial blood pressure (BP), and heart rate (HR). This response to NMDA was significantly potentiated (27±7%) in HF compared with sham rats. On the other hand, microinjection of the NMDA receptor antagonist AP-5 (4 to 16 nmol) into the PVN caused significant decreases in RSND, BP, and HR only in rats with HF but very slight changes in sham rats. Furthermore, using microdialysis and HPLC in combination with electrochemical detection techniques, we found that the glutamate level in the PVN was not increased significantly in HF compared with sham rats. However, using RT-PCR, Western blot, and immunofluorescence techniques, it was found that NMDA NR
1
subunit mRNA expression and protein level in the PVN were significantly increased in HF compared with sham rats. These data suggest that the increased glutamatergic activity on sympathetic regulation, due to the upregulation of NMDA NR
1
receptor subunits within the PVN may contribute to the elevated sympathoexcitation during HF.
Mechanisms of Hepatocyte Growth Factor–Mediated Vascular Smooth Muscle Cell Migration
Authors: Ma Harry , Calderon Tina M. , Kessel Tamar , Ashton Anthony W. , Berman Joan W.
Published: October 2003

The migration of vascular smooth muscle cells (SMCs) from the media into the neointima and their subsequent proliferation is important in the pathogenesis of atherosclerosis. This process is regulated by multiple factors, including growth factors, and involves changes in the interaction of SMCs with the extracellular matrix and in intracellular signaling cascades that regulate cell movement. We demonstrated previously that hepatocyte growth factor (HGF) is expressed in human atherosclerotic plaques. Although HGF has been shown to promote SMC migration, the mechanisms involved in this process have not been characterized fully. In this study, inhibitory antibodies were used to determine which integrins mediated HGF-induced SMC migration. Inhibition of β
1
or β
3
integrin resulted in a significant decrease in migration. Subsequent experiments were performed to characterize additional biochemical mechanisms involved in HGF-mediated migration. HGF induced the redistribution of focal adhesions, the activation of focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) and their increased association with β
1
and β
3
integrins, and the production of pro-matrix metalloproteinase-2. Migration levels were significantly reduced by cotreatment of SMCs with the extracellular signal–regulated kinase 1/2 (ERK1/2) inhibitor, UO126, the p38 inhibitor, SB203580, or the phosphatidylinositol-3 kinase inhibitor, LY294002. In HGF-treated SMCs, focal adhesion redistribution and FAK and Pyk2 activation were decreased by ERK1/2 inhibition. Neither SB203580 nor LY294002 inhibited HGF-induced ERK1/2 activation. Thus, ERK1/2 signaling may play an important role in HGF-mediated SMC migration by contributing to focal adhesion redistribution and FAK and Pyk2 activation.
Blood Pressure Reduction and Secondary Prevention of Stroke and Other Vascular Events
Authors: Rashid Parveen , Leonardi-Bee Jo , Bath Philip
Published: October 2003

Background—

High blood pressure is a risk factor for stroke recurrence. We assessed the effectiveness of lowering blood pressure in preventing recurrent vascular events in patients with previous stroke or transient ischemic attack.

Summary of Review—

We performed a systematic review and meta-regression of completed randomized controlled trials that investigated the effect of lowering blood pressure on recurrent vascular events in patients with prior ischemic or hemorrhagic stroke or transient ischemic attack. Trials were identified from searches of 3 electronic databases (Cochrane Library, EMBASE, MEDLINE). Seven randomized controlled trials, with 8 comparison groups, were included. Lowering blood pressure or treating hypertension with a variety of antihypertensive agents reduced stroke (odds ratio [OR], 0.76; 95% CI, 0.63 to 0.92), nonfatal stroke (OR, 0.79; 95% CI, 0.65 to 0.95), myocardial infarction (OR, 0.79; 95% CI, 0.63 to 0.98), and total vascular events (OR, 0.79; 95% CI, 0.66 to 0.95). No effect was seen on vascular or all-cause mortality. Heterogeneity was present for several outcomes and was partly related to the class of antihypertensive drugs used; angiotensin-converting enzyme inhibitors and diuretics separately, and especially together, reduced vascular events, while β-receptor antagonists had no discernable effect. The reduction in stroke was related to the difference in systolic blood pressure between treatment and control groups (
P
=0.002).

Conclusions—

Evidence from randomized controlled trials supports the use of antihypertensive agents in lowering blood pressure for the prevention of vascular events in patients with previous stroke or transient ischemic attack. Vascular prevention is associated positively with the magnitude by which blood pressure is reduced.
Photothrombotic Middle Cerebral Artery Occlusion and Reperfusion Laser System in Spontaneously Hypertensive Rats
Authors: Yao Hiroshi , Sugimori Hiroshi , Fukuda Kenji , Takada Junichi , Ooboshi Hiroaki , Kitazono Takanari , Ibayashi Setsuro , Iida Mitsuo
Published: October 2003

Background and Purpose—

To establish a less invasive and reproducible focal ischemia model in the rat, we adopted a 2-laser system (ie, photothrombosis and YAG laser–induced reperfusion).

Methods—

The distal middle cerebral artery (MCA) of spontaneously hypertensive rats was occluded by 568-nm krypton laser and intravenous infusion of the photosensitizing dye rose bengal and was recanalized by 355-nm ultraviolet laser irradiation. Cerebral blood flow was determined by laser-Doppler flowmetry at the penumbral cortex. Infarct volume was determined at 3 days after distal MCA occlusion.

Results—

Brain temperature determined with infrared thermography was maintained within an acceptable range of approximately 1°C upper shift of the center of brain temperature distribution during krypton or YAG laser irradiation. The average of the values (23 experiments; n=163) of coefficient of variation of infarct volume was 21±6%, indicating high reproducibility of this model. After distal MCA occlusion, cerebral blood flow was decreased to 32±16% of the control values and was increased to 98±21% after YAG laser–induced reperfusion. Infarct volume in these rats was 61±18 mm
3
(coefficient of variation=30%; n=6).

Conclusions—

We have characterized a highly reproducible focal ischemia model utilizing a 2-laser system, one to induce thrombotic MCA occlusion and the other to facilitate reperfusion.
Unexpected Nocturnal Hypoxia in Patients With Acute Stroke
Authors: Roffe Christine , Sills Sheila , Halim Mohamed , Wilde Kathryn , Allen Martin B. , Jones Peter W. , Crome Peter
Published: October 2003

Background and Purpose—

Patients who have had a stroke are at risk of hypoxia through alterations in the central regulation of respiration, through aspiration, and through respiratory muscle weakness. Sleep-related breathing disorders are common and may lead to episodes of nocturnal hypoxia even when daytime oxygenation is normal. The aim of this study was to assess the prevalence of unexpected nocturnal hypoxia in stroke patients.

Methods—

Consecutive adult patients with stroke were recruited within 72 hours of admission to hospital. Patients with indications for oxygen treatment were excluded. Older adults from the local community were recruited as control subjects. Oxygenation was assessed by pulse oximetry (Minolta 3i) for 5 minutes when awake before bedtime and continuously from 11
pm
until 7
am
.

Results—

Of the 238 potentially eligible stroke patients, 120 were excluded because they required oxygen, 118 were recruited, and 100 had adequate pulse oximetry data. The mean±SD age was 74±8 years for stroke patients and 72±8 years for control subjects (n=85). Mean awake oxygen saturation (S
o
2
) was 94.5±1.7% for the stroke group and 95.8±1.7% for the control group (
P
<0.001). Mean nocturnal S
o
2
was 93.5±1.9% in stroke patients and 94.3±1.9% in control subjects (
P
<0.01). Stroke patients had a higher oxygen desaturation index (ODI 4%) (8.9 versus 2.1,
P
<0.001). In addition, 23% of stroke patients spent >30 minutes with S
o
2
<90% during the night.

Conclusions—

Oxygen saturation at night is ≈1% lower than when awake. Almost a quarter of stroke patients who are normoxic at screening during the day spend >30 minutes with an oxygen saturation <90%.
Anatomy and Functionality of Leptomeningeal Anastomoses
Authors: Brozici Mariana , van der Zwan Albert , Hillen Berend
Published: October 2003

Background—

This review seeks to provide a structured presentation of existing knowledge of leptomeningeal anastomoses from anatomic and functional points of view and to identify problems and possible research directions to foster a better understanding of the subject and of stroke mechanisms.

Summary of Review—

Available data show that leptomeningeal anastomoses may be important in understanding stroke mechanisms and that leptomeningeal anastomoses play an important role in penumbra outcome. However, the literature shows no consensus between statements on the existence of leptomeningeal anastomoses and compensatory capacity.

Conclusions—

By analyzing the available literature and identifying the factors that contribute to this confusion, we found that variability and the functional consequences thereof are important but that quantitative data are lacking. Moreover, vascular remodeling is an issue to consider.
Access to Care, Acculturation, and Risk Factors for Stroke in Mexican Americans
Authors: Smith Melinda A. , Risser Jan M.H. , Lisabeth Lynda D. , Moyé Lemuel A. , Morgenstern Lewis B.
Published: October 2003

Background and Purpose—

Mexican Americans are the largest subgroup of Hispanic Americans, now the most numerous US minority population. We compared access to care, acculturation, and biological risk factors among Mexican American and non-Hispanic white stroke patients and the general population.

Methods—

The Brain Attack Surveillance in Corpus Christi project is a population-based stroke surveillance study conducted in southeast Texas. All stroke cases were ascertained through active and passive surveillance from January 2000 through April 2002 and compared with population estimates from a random-digit telephone survey.

Results—

Compared with non-Hispanic white stroke patients (n=405), Mexican American stroke patients (n=403) were less likely to have graduated from high school (odds ratio [OR], 15.4; 95% confidence interval [CI], 10.6 to 22.4) and more likely to earn less than $20 000 per year (OR, 6.5; 95% CI, 4.5 to 9.4). Mexican American stroke patients were more likely to have diabetes (OR, 2.7; 95% CI, 2.0 to 3.7) and less likely to have atrial fibrillation (OR, 0.5; 95% CI, 0.4 to 0.8). Compared with population estimates (n=719), stroke was associated with diabetes (Mexican Americans: OR, 3.6; 95% CI, 2.2 to 5.8; non-Hispanic whites: OR, 3.0; 95% CI, 1.7 to 5.5), hypertension (Mexican Americans: OR, 2.8; 95% CI, 1.8 to 4.3; non-Hispanic whites: OR, 3.3; 95% CI, 2.2 to 5.0), lower incomes (Mexican Americans: OR, 3.4; 95% CI, 2.1 to 5.4; non-Hispanic whites: OR, 3.0; 95% CI, 1.7 to 5.2), and lower educational attainment (Mexican Americans: OR, 5.1; 95% CI, 3.2 to 8.1; non-Hispanic whites: OR, 4.5; 95% CI, 2.2 to 9.3).

Conclusions—

Biological and social variables are associated with stroke to a similar extent in both Mexican Americans and non-Hispanic whites. Health behavior interventions for both populations may follow from this work. Stroke disparities between these populations may be explained only partially by differences in the prevalence of currently identified biological and social factors.
Beyond Mismatch
Authors: Kidwell Chelsea S. , Alger Jeffry R. , Saver Jeffrey L.
Published: October 2003

Background—

The ability to quickly and efficiently identify the ischemic penumbra in the acute stroke clinical setting is an important goal for stroke researchers and clinicians. Early and accurate identification of potentially salvageable versus irreversibly infarcted brain tissue may enable selection of the most appropriate candidates for early stroke therapies and identify patients who may still benefit from late recanalization or neuroprotective treatment. Recent advances in magnetic resonance imaging of the ischemic penumbra have been driven by serial MRI studies characterizing the natural evolution of cerebral infarction as well as the brain’s response to reperfusion.

Summary of Comment—

Based on these studies, various models for imaging the penumbra with MRI have been proposed, including the pioneering diffusion-perfusion mismatch model and later multivariate approaches. Each model has its own unique advantages and disadvantages.

Conclusions—

There now are sufficient data to support paradigm shifts in a variety of central tenets regarding MRI and the ischemic penumbra. These include the insights that diffusion-perfusion mismatch does not optimally define the penumbra; that early diffusion lesions are in part reversible and often include both irreversibly infarcted tissue and penumbra; that the visible zone of perfusion abnormality overestimates the penumbra by including regions of benign oligemia; that MRI is a very practical method for acute stroke imaging; and that therapeutic salvage of the ischemic penumbra has been demonstrated in humans using diffusion-perfusion MRI.
Effect of Area-Based Deprivation on the Severity, Subtype, and Outcome of Ischemic Stroke
Authors: Aslanyan Stella , Weir Christopher J. , Lees Kennedy R. , Reid John L. , McInnes Gordon T.
Published: October 2003

Background and Purpose—

Markers of low socioeconomic status (deprivation) are associated with stroke and its causes. In the United Kingdom, area-based deprivation measures are available routinely through links with postal codes. We hypothesized that deprivation is associated with ischemic stroke risk factors, severity, subtype, and outcome.

Methods—

We studied 2026 patients, each with at least 2 years of outcome follow-up by record linkage after first admission with ischemic stroke to an acute stroke unit. Baseline factors recorded routinely were age, sex, medical history, blood pressure, and stroke severity and subtype. Deprivation was assessed by the Womersley score (WS) and Murray score (MS).

Results—

Higher WS and MS were associated with stroke at younger age (eg, WS linear regression coefficient (
r
)=−0.26; 95% confidence interval [CI], −0.51 to −0.01 per additional point), smoking (odds ratio [OR], 1.12; 95% CI, 1.08 to 1.17), and claudication (OR, 1.09; 95% CI, 1.01 to 1.17); WS was associated with higher systolic blood pressure (
r
=0.13; 95% CI, 0.02 to 0.24); and MS was associated with severe stroke. Deprivation was not associated with case fatality in univariate analysis or after correction for all baseline factors. Deprivation was associated with readmission to hospital as a result of any vascular event in univariate analysis (hazard ratio [HR], 1.05; 95% CI, 1.02 to 1.09) and after correction for all baseline factors (HR, 1.06; 95% CI, 1.02 to 1.10).

Conclusions—

Tackling health inequalities in stroke should focus on stroke primary prevention by tackling deprivation, including promoting changes in lifestyle.
Chemokine receptor–8 (CCR8) mediates human vascular smooth muscle cell chemotaxis and metalloproteinase-2 secretion
Authors: Haque Nasreen S. , Fallon John T. , Pan Jiang Jin , Taubman Mark B. , Harpel Peter C.
Published: October 2003

The response of the arterial vascular wall to injury is characterized by vascular smooth muscle cell (VSMC) migration, a process requiring metalloproteinase production. This migration is induced by cytokines, however the agonists involved are not fully defined. The CC chemokine receptor 8 (CCR8) is expressed on monocytes and T lymphocytes and is the sole receptor for the human CC chemokine 1 (CCL1, I-309) and for the viral chemokine, vCCL1 (viral macrophage inflammatory protein 1 [vMIP-1]). We have reported that CCR8 is expressed on human umbilical vein endothelial cells (HUVECs) and mediates chemotaxis induced by CCL1. The conditioned medium from incubation mixtures of lipoprotein(a) (Lp(a)) and HUVECs (LCM) contained CCL1 and stimulated both monocyte and HUVEC chemotaxis, providing novel mechanisms for the atherogenicity of Lp(a). We now report that CCL1, vCCL1, and LCM stimulate chemotaxis of human VSMCs that is blocked by murine monoclonal antibody against CCR8 and by the G-protein inhibitor pertussis toxin. The effect of anti-CCR8 was specific, as this antibody failed to effect the chemotaxis of VSMCs in response to CCL3 or by platelet-derived growth factor BB (PDGF-BB). VSMCs contained CCR8 mRNA and CCR8 antigen coprecipitated with VSMC membranes. Antibodies against metalloproteinase-2 (MMP-2) inhibited the CCL1-induced chemotaxis of VSMCs, whereas anti–MMP-9 was less effective. CCL1 induced VSMC pro–MMP-2 mRNA and protein secretion. Poxvirus MC148 inhibited the increase in MMP-2 induced by CCL1, documenting that CCR8 was the receptor responsible. In mouse femoral arteries, CCR8 and TCA3 antigen colocalized with VSMCs and were up-regulated after injury. The induction of CCR8 and CCL1/TCA3 under conditions associated with VSMC proliferation and migration raises the possibility that CCR8 may play an important role in vessel wall pathology.
Early prediction of response in patients with relapsed or refractory Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ALL) treated with imatinib
Authors: Wassmann Barbara , Pfeifer Heike , Scheuring Urban J. , Binckebanck Anja , Gökbuget Nicola , Atta Johannes , Brück Patrick , Rieder Harald , Schoch Claudia , Leimer Lothar , Schwerdtfeger Rainer , Ehninger Gerhard , Lipp Thomas , Perz Jolanta , Stelljes Matthias , Gschaidmeier Harald , Hoelzer Dieter , Ottmann Oliver G.
Published: October 2003

Imatinib has pronounced but brief antileukemic activity in advanced Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ALL). We assessed the prognostic impact of pretreatment disease features and the early bone marrow (BM) response in 68 consecutive patients with Ph+ALL receiving imatinib salvage therapy. A complete hematologic or marrow response was achieved by 92% of patients with BM blasts below 5% on day 14, whereas 62.5% of patients with more than 5% BM blasts on day 14 were nonresponders. Similarly, time to progression (TTP) was superior in patients with a good day 14 response (5.2 versus 0.9 months; P < .0001). Prior complete remission of less than 6 months, white blood cell count of more than 10 × 109/L, circulating peripheral blood blasts at diagnosis, additional Philadelphia chromosomes, or at least 2 Bcr-Abl fusion signals were associated with significantly inferior remission rate and response duration. In patients without poor prognostic features, single-agent imatinib may be appropriate before transplant salvage therapy. Conversely, patients with clinically or cytogenetically defined poor-risk features are candidates for trials of upfront imatinib in combination with other agents.
An inhibitor of the EGF receptor family blocks myeloma cell growth factor activity of HB-EGF and potentiates dexamethasone or anti–IL-6 antibody-induced apoptosis
Authors: Mahtouk Karène , Jourdan Michel , De Vos John , Hertogh Catherine , Fiol Geneviève , Jourdan Eric , Rossi Jean-François , Klein Bernard
Published: October 2003

We previously found that some myeloma cell lines express the heparin-binding epidermal growth factor–like growth factor (HB-EGF) gene. As the proteoglycan syndecan-1 is an HB-EGF coreceptor as well as a hallmark of plasma cell differentiation and a marker of myeloma cells, we studied the role of HB-EGF on myeloma cell growth. The HB-EGF gene was expressed by bone marrow mononuclear cells in 8 of 8 patients with myeloma, particularly by monocytes and stromal cells, but not by purified primary myeloma cells. Six of 9 myeloma cell lines and 9 of 9 purified primary myeloma cells expressed ErbB1 or ErbB4 genes coding for HB-EGF receptor. In the presence of a low interleukin-6 (IL-6) concentration, HB-EGF stimulated the proliferation of the 6 ErbB1+ or ErbB4+ cell lines, through the phosphatidylinositol 3-kinase/AKT (PI-3K/AKT) pathway. A pan-ErbB inhibitor blocked the myeloma cell growth factor activity and the signaling induced by HB-EGF. This inhibitor induced apoptosis of patients'myeloma cells cultured with their tumor environment. It also increased patients' myeloma cell apoptosis induced by an anti–IL-6 antibody or dexamethasone. The ErbB inhibitor had no effect on the interaction between multiple myeloma cells and stromal cells. It was not toxic for nonmyeloma cells present in patients' bone marrow cultures or for the growth of hematopoietic progenitors. Altogether, these data identify ErbB receptors as putative therapeutic targets in multiple myeloma.
Dose-escalated donor lymphocyte infusions following reduced intensity transplantation: toxicity, chimerism, and disease responses
Authors: Peggs Karl S. , Thomson Kirsty , Hart Daniel P. , Geary Johanne , Morris Emma C. , Yong Kwee , Goldstone Anthony H. , Linch David C. , Mackinnon Stephen
Published: October 2003

Data on the application of donor lymphocyte infusions (DLIs) following reduced-intensity transplantation (RIT) remain limited. Persistence of host antigen-presenting cells might increase the efficacy or toxicity of cellular immunotherapies. We report the results of dose-escalating DLIs in 46 patients undergoing RIT, who received a total of 109 infusions to treat mixed chimerism or residual or progressive disease. Diagnoses were myeloma (n = 19), Hodgkin lymphoma (n = 13), non-Hodgkin lymphoma (n = 10), and other (n = 4). Thirty-two had an HLA-matched family donor and 14 an unrelated donor. Grades II to IV graft-versus-host disease (GVHD) occurred in 5 sibling and 7 unrelated donor recipients. GVHD was more common (P = .002), occurred at lower T-cell doses, and was more severe in the unrelated donor cohort. Conversion from mixed to multilineage full donor chimerism occurred in 30 of 35 evaluable patients. Presence of mixed chimerism in the granulocyte lineage at the time of DLI did not predict for chimerism response or GVHD. Disease responses occurred in 63% of patients with myeloma and 70% of those with Hodgkin lymphoma and were not predicted by changes in chimerism. These data support the presence of clinically relevant graft-versus-Hodgkin activity and indicate that DLI may be associated with a significantly increased toxicity in unrelated compared to sibling donor transplant recipients receiving identical treatment protocols.
Geldanamycin and herbimycin A induce apoptotic killing of B chronic lymphocytic leukemia cells and augment the cells' sensitivity to cytotoxic drugs
Authors: Jones Dylan T. , Addison Elena , North Janet M. , Lowdell Mark W. , Hoffbrand A. Victor , Mehta Atul B. , Ganeshaguru Kanagasabai , Folarin Najeem I. , Wickremasinghe R. Gitendra
Published: October 2003

We studied the actions of geldanamycin (GA) and herbimycin A (HMA), inhibitors of the chaperone proteins Hsp90 and GRP94, on B chronic lymphocytic leukemia (CLL) cells in vitro. Both drugs induced apoptosis of the majority of CLL isolates studied. Whereas exposure to 4-hour pulses of 30 to 100 nM GA killed normal B lymphocytes and CLL cells with similar dose responses, T lymphocytes from healthy donors as well as those present in the CLL isolates were relatively resistant. GA, but not HMA, showed a modest cytoprotective effect toward CD34+ hematopoietic progenitors from normal bone marrow. The ability of bone marrow progenitors to form hematopoietic colonies was unaffected by pulse exposures to GA. Both GA and HMA synergized with chlorambucil and fludarabine in killing a subset of CLL isolates. GA- and HMA-induced apoptosis was preceded by the up-regulation of the stress-responsive chaperones Hsp70 and BiP. Both ansamycins also resulted in down-regulation of Akt protein kinase, a modulator of cell survival. The relative resistance of T lymphocytes and of CD34+ bone marrow progenitors to GA coupled with its ability to induce apoptosis following brief exposures and to synergize with cytotoxic drugs warrant further investigation of ansamycins as potential therapeutic agents in CLL.
Isolation of multipotent mesenchymal stem cells from umbilical cord blood
Authors: Lee Oscar K. , Kuo Tom K. , Chen Wei-Ming , Lee Kuan-Der , Hsieh Shie-Liang , Chen Tain-Hsiung
Published: October 2003

It is well accepted that umbilical cord blood has been a source for hematopoietic stem cells. However, controversy exists as to whether cord blood can serve as a source of mesenchymal stem cells, which can differentiate into cells of different connective tissue lineages such as bone, cartilage, and fat, and little success has been reported in the literature about the isolation of such cells from cord blood. Here we report a novel method to obtain single cell-derived, clonally expanded mesenchymal stem cells that are of multilineage differentiation potential by negative immunoselection and limiting dilution. The immunophenotype of these clonally expanded cells is consistent with that reported for bone marrow mesenchymal stem cells. Under appropriate induction conditions, these cells can differentiate into bone, cartilage, and fat. Surprisingly, these cells were also able to differentiate into neuroglial- and hepatocyte-like cells under appropriate induction conditions and, thus, these cells may be more than mesenchymal stem cells as evidenced by their ability to differentiate into cell types of all 3 germ layers. In conclusion, umbilical cord blood does contain mesenchymal stem cells and should not be regarded as medical waste. It can serve as an alternative source of mesenchymal stem cells to bone marrow.
Chronic active Epstein-Barr virus infection associated with mutations in perforin that impair its maturation
Authors: Katano Harutaka , Ali Mir A. , Patera Andriani C. , Catalfamo Marta , Jaffe Elaine S. , Kimura Hiroshi , Dale Janet K. , Straus Stephen E. , Cohen Jeffrey I.
Published: October 2003

Chronic active Epstein-Barr virus infection (CAEBV) is a rare disease in which previously healthy persons develop severe, life-threatening illness. Mutations in the perforin gene have been found in familial hemophagocytic lymphohistiocytosis, which shares some features with CAEBV. We studied a patient who died at age 18, 10 years after the onset of CAEBV. The patient had high titers of antibodies to EBV, EBV RNA in lymph nodes, T-cell lymphoproliferative disease, and hemophagocytic lymphohistiocytosis. DNA sequencing showed novel mutations in both alleles of the perforin gene that resulted in amino acid changes in the protein. The quantity of the native form of perforin from the patient's stimulated peripheral blood mononuclear cells (PBMCs) was extremely low and immunoblotting showed accumulation of an uncleaved precursor form of perforin. Stimulated PBMCs from the patient were defective for Fas-independent cytotoxicity. These data imply that mutations in this patient resulted in reduced perforin-mediated cytotoxicity by his lymphocytes. This is the first case in which perforin mutations have been shown to result in accumulation of the uncleaved, immature form of perforin. Mutations in the perforin gene are associated with some cases of CAEBV with hemophagocytic lymphohistiocytosis.
Identification of a 4-base deletion in the gene in inherited intrinsic factor deficiency
Authors: Yassin Fawwaz , Rothenberg Sheldon P. , Rao Sreedhar , Gordon Marilyn M. , Alpers David H. , Quadros Edward V.
Published: October 2003

A 4-base deletion has been identified in the coding region of the gene for gastric intrinsic factor (IF) in an 11-year-old girl with severe anemia and cobalamin (Cbl) deficiency. The bone marrow showed frank megaloblastic morphology, and the Schilling test indicated a failure to absorb Cbl that was corrected by coadministration of IF. Pentagastrin administration induced acid secretion, but the gastric juice lacked IF as determined by CbI binding, by fractionation of protein-bound CbI, and by immunoprecipitation with anti-IF antiserum. Individual exons were amplified by the polymerase chain reaction by using primers to the flanking intronic regions, and the nucleotide sequence analysis identified a 4-base deletion (c183_186delGAAT) spanning positions 104 to 107 in exon 2, resulting in premature termination of translation. This mutation also eliminates a site for Bst XI endonuclease and introduces a site for BsaBI for identifying this deletion in hereditary IF deficiency.
Identification of the molecular requirements for an RARα-mediated cell cycle arrest during granulocytic differentiation
Authors: Walkley Carl R. , Purton Louise E. , Snelling Hayley J. , Yuan Yang-Dar , Nakajima Hideaki , Chambon Pierre , Chandraratna Roshantha A. S. , McArthur Grant A.
Published: October 2003

Retinoids are potent inducers of cell cycle arrest and differentiation of numerous cell types, notably granulocytes. However the mechanisms by which retinoids mediate cell cycle arrest during differentiation remain unclear. We have used myeloid differentiation to characterize the molecular pathways that couple cell cycle withdrawal to terminal differentiation. Using primary cells from mice deficient for either the cyclin-dependent kinase inhibitor (CDKi) p27Kip1, the Myc antagonist Mad1, or both Mad1 and p27Kip1, we observed that signals mediated through retinoic acid receptor α (RARα), but not RARβ or γ, required both Mad1 and p27Kip1 to induce cell cycle arrest and to accelerate terminal differentiation of granulocytes. Although RARα did not directly regulate Mad1 or p27Kip1, the RARα target gene C/EBPϵ directly regulated transcription of Mad1. Induction of C/EBPϵ activity in granulocytic cells led to rapid induction of Mad1 protein and transcript, with direct binding of C/EBPϵ to the Mad1 promoter demonstrated through chromatin immunoprecipitation assay. These data demonstrate that cell cycle arrest in response to RARα specifically requires Mad1 and p27Kip1 and that Mad1 is transcriptionally activated by CCAAT/enhancer-binding protein ϵ (C/EBPϵ). Moreover, these data demonstrate selectivity among the RARs for cell cycle arrest pathways and provide a direct mechanism to link differentiation induction and regulation of the Myc antagonist Mad1.
A haplotype of the EPCR gene is associated with increased plasma levels of sEPCR and is a candidate risk factor for thrombosis
Authors: Saposnik Beatrice , Reny Jean-Luc , Gaussem Pascale , Emmerich Joseph , Aiach Martine , Gandrille Sophie
Published: October 2003

The endothelial cell protein C (PC) receptor (EPCR) facilitates PC activation by the thrombin-thrombomodulin complex. A soluble form of this receptor (sEPCR) found in plasma inhibits both activated PC (aPC) activity and PC activation by competing for PC with membrane-associated EPCR. Elevated sEPCR levels are found in approximately 20% of healthy subjects, but the mechanisms underlying this interindividual variability are unknown. We measured sEPCR levels in 100 healthy male volunteers, and observed 2 phenotypic groups of subjects. The temporal stability of sEPCR levels suggested genetic control. Extensive analysis of the EPCR gene in these subjects revealed 13 polymorphisms in complete linkage disequilibrium; these defined 3 haplotypes, 1 of which (A3) was strongly associated with high sEPCR levels. The high constitutive sEPCR levels observed in A3 haplotype carriers might reduce the efficiency of the PC system and predispose these subjects to venous thrombosis. By studying 338 patients with venous thrombosis and 338 age- and sex-matched healthy subjects, we found that the A3 haplotype was overrepresented in the patients. In multivariate analysis, subjects carrying the A3 haplotype had an increased risk of thrombosis (odds ratio [OR] = 1.8; P = .004). Thus, the A3 haplotype, which is associated with elevated plasma sEPCR levels, is a candidate risk factor for venous thrombosis.
Suppression of in vitro megakaryocyte production by antiplatelet autoantibodies from adult patients with chronic ITP
Authors: McMillan Robert , Wang Lei , Tomer Aaron , Nichol Janet , Pistillo Jeanne
Published: October 2003

Chronic immune thrombocytopenic purpura (ITP) is manifested by autoantibody-induced platelet destruction. Platelet turnover studies suggest that autoantibody may also affect platelet production. To evaluate this, we studied the effect of plasma from adult patients with chronic ITP on in vitro megakaryocyte production. CD34+ cells, obtained from healthy donors, were cultured in medium containing PEG-rHuMGDF and 10% plasma from either ITP patients or healthy subjects. Cultures containing plasma from 12 of 18 ITP patients showed a significant decrease (26%-95%) in megakaryocyte production when compared with control cultures. Positive ITP plasmas not only reduced the total number of megakaryocytes produced during the culture period but also inhibited megakaryocyte maturation, resulting in fewer 4N, 8N, and 16N cells. The role of antibody in this suppression is supported by 2 factors: (1) immunoglobulin G (IgG) from ITP patients inhibited megakaryocyte production when compared with control IgG; and (2) adsorption of autoantibody, using immobilized antigen, resulted in significantly less inhibition of megakaryocyte production when compared with unadsorbed plasma. These results show that plasma autoantibody from some adult patients with ITP inhibits in vitro megakaryocyte production, suggesting that a similar effect may occur in vivo.