bluuebunny/crossref_metadata_2025 huggingface dataset:
Raloxifene Prevents Cardiac Hypertrophy and Dysfunction in Pressure-Overloaded Mice
Authors: Ogita Hisakazu , Node Koichi , Liao Yulin , Ishikura Fuminobu , Beppu Shintaro , Asanuma Hiroshi , Sanada Shoji , Takashima Seiji , Minamino Tetsuo , Hori Masatsugu , Kitakaze Masafumi
Published: December 2003

17β-Estradiol reduces myocardial hypertrophy and left ventricular mass, suggesting that the selective estrogen receptor modulator raloxifene may have similar effects. However, it is not clear whether raloxifene inhibits both cardiac hypertrophy and dysfunction. We used transverse aortic-banded mice to produce pressure-overload cardiac hypertrophy and used neonatal rat ventricular cardiomyocytes to investigate the cellular mechanisms of raloxifene on cardiac hypertrophy. Left ventricular mass and fractional shortening of mice hearts were measured by transthoracic echocardiography. Protein synthesis of cardiomyocytes was evaluated by incorporation of [
3
H]leucine into cardiomyocytes exposed to angiotensin II. Phosphorylation of mitogen-activated protein (MAP) kinase was also observed in cardiomyocytes. Raloxifene prevented increases in left ventricular mass and decreases of fractional shortening at 4 weeks after aortic banding. Pretreatment with raloxifene before angiotensin II stimulation inhibited the increase in [
3
H]leucine incorporation into neonatal rat cardiomyocytes in a concentration-dependent manner. This inhibition was partially but not significantly attenuated by
N
G
-nitro-
l
-arginine methyl ester (
l
-NAME), an inhibitor of nitric oxide synthase, and completely abolished by ICI182780, an estrogen receptor antagonist. Although the phosphorylation of p38 MAP kinase, c-Jun N-terminal kinase (JNK), or extracellular signal-regulated protein kinase (ERK) in cardiomyocytes was significantly increased by angiotensin II stimulation as compared with the control, pretreatment with raloxifene attenuated p38 MAP kinase phosphorylation, but neither JNK nor ERK phosphorylation. We conclude that raloxifene inhibits cardiac hypertrophy and dysfunction and that the inhibition of p38 MAP kinase phosphorylation after the stimulation of estrogen receptors may be involved in the cellular mechanisms of this agent.
Effect of Birth Weight on Blood Pressure and Body Size in Early Adolescence
Authors: Falkner Bonita , Hulman Sonia , Kushner Harvey
Published: December 2003

The fetal programming theory that birth weight contributes to blood pressure or body size in later life is examined in this study. A prospective longitudinal study was conducted on subjects who were examined as newborns and prospectively interviewed and re-examined at 11 to 14 years old. Low birth weight (<2500 g) was present in 36% of the sample. The adolescent examination included measurements of blood pressure (BP), both auscultation and oscillometric methods; anthropometrics (height, weight, and body mass index [BMI]); health status; and health behaviors. Data were analyzed on 250 subjects. Correlation coefficients of birth weight with all BP measures were nonsignificant, except for the last auscultated diastolic BP (
r
=0.19,
P
<0.01), which had a positive relationship. The simple correlation coefficients of birth weight with adolescent body size were significant and positive for weight and BMI. After multiple linear regression analyses with adjustments for age, Tanner stage, and gestational age, there was no significant effect of birth weight on adolescent weight or BMI. No significant correlations were detected for ponderal index at birth with adolescent measures. This study, which includes a substantial portion of low-birth-weight cases (36%), indicates that birth weight does not correlate negatively with later BP. These results do not support the low-birth-weight theory and indicate that childhood factors that are more proximal have a greater effect on adolescent BP than intrauterine factors.
Morphological and Functional Alterations in Ventricular Myocytes From Male Transgenic Mice With Hypertrophic Cardiomyopathy
Authors: Olsson M. Charlotte , Palmer Bradley M. , Stauffer Brian L. , Leinwand Leslie A. , Moore Russell L.
Published: December 2003

Familial hypertrophic cardiomyopathy (FHC) is a human genetic disorder caused by mutations in sarcomeric proteins. It is generally characterized by cardiac hypertrophy, fibrosis, and myocyte disarray. A transgenic mouse model of FHC with mutations in the actin-binding domain of the α-myosin heavy chain (MyHC) gene displays many phenotypes similar to human FHC. At 4 months, male transgenic (TG) mice present with concentric cardiac hypertrophy that progresses to dilation with age. Accompanying this latter morphological change is systolic and diastolic dysfunction. Left ventricular (LV) myocytes from male TG and wild-type (WT) littermates at 5 and 12 months of age were isolated and used for morphological and functional studies. Myocytes from 5- and 12-month-old TG animals had shorter sarcomere lengths compared with WT. This sarcomere length difference was abolished in the presence of 2,3-butanedione monoxime, suggesting that the basal level of contractile element activation was increased in TG myocytes. Myocytes from 12-month-old TG mice were significantly longer than those from age-matched WT controls, and TG myocytes exhibited Z-band disorganization. When cells were paced at 0.5 Hz, TG myocyte relengthening and the fall in intracellular [Ca
2+
] were slowed when compared with cells from age-matched WT controls. Moreover, an increased amount of β-myosin heavy chain protein was found in hearts from TG compared with WT. Thus, myocytes from the α-MyHC TG mouse model display many morphological and functional abnormalities that may help explain the LV dysfunction seen in this TG mouse model of FHC.
Smooth Muscle—Specific Expression of CYP4A1 Induces Endothelial Sprouting in Renal Arterial Microvessels
Authors: Jiang Miao , Mezentsev Alexandre , Kemp Rowena , Byun Kihwan , Falck John R. , Miano Joseph M. , Nasjletti Alberto , Abraham Nader G. , Laniado-Schwartzman Michal
Published: December 2003

Cytochrome P450 (CYP) 4A1 has been characterized as the most efficient arachidonic acid ω-hydroxylase catalyzing the formation of 20-hydroxyeicosatetraenoic acid (20-HETE), a potent constrictor of the renal and cerebral microcirculation and a mitogen for smooth muscle cells. We constructed adenoviruses expressing the CYP4A1 cDNA or LacZ under the control of the smooth muscle cell–specific promoter SM22α (Ad-SM22-4A1 and Ad-SM22-nLacZ, respectively). β-Galactosidase expression was detected in Ad-SM22-nLacZ–transduced vascular smooth muscle A7r5 and PAC1 cells, but not in Ad-SM22-nLacZ-transduced 3T3 fibroblasts or vascular endothelial cells. Likewise, CYP4A1 mRNA and protein were detected in Ad-SM22-4A1–transduced A7r5 and PAC1 cells. Ad-SM22-4A1–transduced A7r5 cells metabolized lauric acid to 12-hydroxy-lauric acid at a rate 5 times greater than that of cells transduced with Ad-SM22-nLacZ (4.79±1.77 versus 0.97±0.57 nmol 12-hydroxy lauric acid/10
6
cells per h). Smooth muscle–specific LacZ expression was also detected in microdissected renal interlobar arteries transduced with Ad-SM22-nLacZ. Arteries transduced with Ad-SM22-4A1 produced higher levels of 20-HETE (4.04±0.29 and 13.43±2.84 ng/mg protein in Ad-SM22-nLacZ–transduced and Ad-SM22-4A1–transduced arteries, respectively) and demonstrated a marked angiogenic activity measured as the total length of sprouting neovessels (12.63±3.66 mm in Ad-SM22-4A1–transduced vessels versus 1.79±0.89 mm in Ad-SM22-nLacZ–transduced vessels). This angiogenic activity represented endothelial cell sprouting and was fully blocked by treatment with HET0016, a selective inhibitor of CYP4A-catalyzed reactions. The inhibitory effect of HET0016 was reversed by addition of a 20-HETE agonist. We conclude that Ad-SM22-4A1 drives a smooth muscle–specific functional expression of CYP4A1 and demonstrates increased angiogenesis, presumably via increased production of 20-HETE.
Cerebral Microvascular Responses to Hypercholesterolemia
Authors: Ishikawa Mami , Stokes Karen Y. , Zhang John H. , Nanda Anil , Granger D. Neil
Published: December 2003

Although hypercholesterolemia is widely accepted as a major risk factor for coronary artery and peripheral vascular diseases, its role in the pathogenesis of stroke is controversial. The objectives of this study were to determine how hypercholesterolemia affects the cerebral microcirculation under resting conditions and after ischemia-reperfusion (I/R). Platelet- and leukocyte-endothelial cell interactions and oxidant production (using the oxidant-sensitive fluorochrome dihydrorhodamine-123) were monitored by intravital videomicroscopy in the cerebral microvasculature of mice placed on either a normal (ND) or cholesterol-enriched diet (HCD). Platelets labeled with carboxyfluorescein diacetate succinimidyl ester (CFDASE) and leukocytes labeled with rhodamine 6G were seen to roll and firmly adhere, with a corresponding increase in oxidant production, in venules of mice on HCD, but not ND. Immunoneutralization of P-selectin attenuated the platelet- and leukocyte-endothelial cell interactions and the enhanced oxidant production associated with HCD. A GPIIb/IIIa blocking antibody did not alter the blood cell-vessel wall interactions to HCD. Mice deficient in the NADPH oxidase subunit gp91
phox
exhibited significantly blunted platelet and leukocyte recruitment responses to HCD. Focal I/R also elicited inflammatory and prothrombogenic responses in cerebral venules and these were exaggerated in mice on HCD. These results implicate an oxidant-dependent, P-selectin–mediated mechanism in the blood cell-vessel wall interactions induced by hypercholesterolemia in the brain and demonstrate that the deleterious effects of I/R on the brain are exacerbated by this cardiovascular risk factor.
Estrogen Elicits Cytochrome P450—Mediated Flow-Induced Dilation of Arterioles in NO Deficiency
Authors: Huang An , Sun Dong , Wu Zhiping , Yan Changdong , Carroll Mairead A. , Jiang Houli , Falck John R. , Kaley Gabor
Published: December 2003

This study investigated the mechanisms responsible for the estrogen-dependent, cytochrome P450 (CYP)-mediated dilator responses to shear stress in arterioles of NO-deficient female rats and mice. Flow-induced dilation (FID) was assessed in isolated arterioles from
N
G
-nitro-
l
-arginine methyl ester (L-NAME)-treated male and ovariectomized female rats before and after overnight incubation with 17β-estradiol (17β-E
2
, 10
−9
mol/L). In control conditions, prostaglandins (PGs) mediated FID, because indomethacin (INDO) abolished the responses. After incubation of the vessels with 17β-E
2
, the basal tone of arterioles was significantly reduced and FID was augmented. INDO did not affect the dilation of the vessels incubated with 17β-E
2
. Dilations of these vessels, however, were eliminated by PPOH and miconazole, inhibitors of CYP/epoxygenase. Simultaneous incubation of the vessels with 17β-E
2
plus ICI, 182,780, an estrogen receptor antagonist, or wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K) phosphorylation or the transcriptional inhibitor DRB, prevented the reduced arteriolar tone and the enhanced CYP-mediated FID caused by incubation of vessels with17β-E
2
. Western blot analysis indicated a significantly increased phospho-Akt level in arterioles incubated with 17β-E
2
compared with those without 17β-E
2
. The enhanced phospho-Akt in response to 17β-E
2
was localized, by immunohistochemistry, to arteriolar endothelial cells. Moreover, GC-MS analysis indicated a significantly increased production of epoxyeicosatrienoic acids, vasodilator metabolites of CYP/epoxygenase, in arterioles incubated with 17β-E
2
, a response that was prevented by ICI 182780 and wortmannin, respectively. Thus, estrogen, via a receptor-dependent, PI3K/Akt-mediated pathway, transcriptionally upregulates CYP activity, leading to an enhanced arteriolar response to shear stress.
Nonlinear Changes of Transmembrane Potential During Electrical Shocks
Authors: Cheek Eric R. , Fast Vladimir G.
Published: December 2003

Defibrillation shocks induce nonlinear changes of transmembrane potential (ΔV
m
) that determine the outcome of defibrillation. As shown earlier, strong shocks applied during action potential plateau cause nonmonotonic negative ΔV
m
, where an initial hyperpolarization is followed by V
m
shift to a more positive level. The biphasic negative ΔV
m
can be attributable to (1) an inward ionic current or (2) membrane electroporation. These hypotheses were tested in cell cultures by measuring the effects of ionic channel blockers on ΔV
m
and measuring uptake of membrane-impermeable dye. Experiments were performed in cell strands (width ≈0.8 mm) produced using a technique of patterned cell growth. Uniform-field shocks were applied during the action potential plateau, and ΔV
m
was measured by optical mapping. Shock-induced negative ΔV
m
exhibited a biphasic shape starting at a shock strength of ≈15 V/cm when estimated peak ΔV
−
m
was ≈−180 mV; positive ΔV
m
remained monophasic. Application of a series of shocks with a strength of 23±1 V/cm resulted in uptake of membrane-impermeable dye propidium iodide. Dye uptake was restricted to the anodal side of strands with the largest negative ΔV
m
, indicating the occurrence of membrane electroporation at these locations. The occurrence of biphasic negative ΔV
m
was also paralleled with after-shock elevation of diastolic V
m
. Inhibition of
I
f
and
I
K1
currents that are active at large negative potentials by CsCl and BaCl
2
, respectively, did not affect ΔV
m
, indicating that these currents were not responsible for biphasic ΔV
m
. These results provide evidence that the biphasic shape of ΔV
m
at sites of shock-induced hyperpolarization is caused by membrane electroporation.
Matrix Metalloproteinase-9 Is Required for Adequate Angiogenic Revascularization of Ischemic Tissues
Authors: Johnson Chad , Sung Hak-Joon , Lessner Susan M. , Fini M. Elizabeth , Galis Zorina S.
Published: December 2003

Angiogenesis, an essential component of a variety of physiological and pathological processes, offers attractive opportunities for therapeutic regulation. We hypothesized that matrix metalloproteinase-9 genetic deficiency (MMP-9
−/−
) will impair angiogenesis triggered by tissue ischemia, induced experimentally by femoral artery ligation in mice. To investigate the role of MMP-9, we performed a series of biochemical and histological analyses, including zymography, simultaneous detection of perfused capillaries, MMP-9 promoter activity, MMP-9 protein, and macrophages in MMP-9
−/−
and wild-type (WT) mice. We found that ischemia resulted in doubling of capillary density in WT and no change in the MMP-9
−/−
ischemic tissues, which translated into increased (39%) perfusion capacity only in the WT at 14 days after ligation. We also confirmed that capillaries in the MMP-9
−/−
presented significantly (
P
<0.05) less points of capillary intersections, interpreted by us as decreased branching. The combined conclusions from simultaneous localizations of MMP-9 expression, capillaries, and macrophages suggested that macrophage MMP-9 participates in capillary branching. Transplantation of WT bone marrow into the MMP-9
−/−
, restored capillary branching, further supporting the contribution of bone marrow–derived macrophages in supplying the necessary MMP-9. Our study indicates that angiogenesis triggered by tissue ischemia requires MMP-9, which may be involved in capillary branching, a potential novel role for this MMP that could be exploited to control angiogenesis.
Interleukin-1β, Transforming Growth Factor-β
1
, and Bradykinin Attenuate Cyclic AMP Production by Human Pulmonary Artery Smooth Muscle Cells in Response to Prostacyclin Analogues and Prostaglandin E
2
by Cyclooxygenase-2 Induction and Downregulation of Adenylyl Cyclase Isoforms 1, 2, and 4
Authors: El-Haroun H. , Bradbury D. , Clayton A. , Knox Alan J.
Published: December 2003

Increased levels of inflammatory cytokines contribute to the pathophysiology of pulmonary hypertension. Prostacyclin (PGI
2
) analogues, which relax pulmonary vessels mainly through cAMP elevation, have a major therapeutic role. In this study, we show that prolonged incubation with bradykinin (BK), interleukin-1β (IL-1β), and transforming growth factor-β
1
(TGF-β
1
) markedly impairs cAMP accumulation in human pulmonary artery smooth muscle cells in response to short-term incubation with prostaglandin E
2
(PGE
2
) and the PGI
2
analogues iloprost and carbaprostacyclin. A similar reduction in cAMP accumulation in response to a direct adenylyl cyclase activator, forskolin, suggested that the effect was attributable to downregulation of adenylyl cyclase. Reverse transcriptase–polymerase chain reaction studies showed downregulation of adenylyl cyclase isoforms 1, 2, and 4. The effect of IL-1β, BK, and TGF-β
1
on cAMP levels was abrogated by the selective COX-2 inhibitor NS398. Furthermore, it was mimicked by prolonged incubation with the COX-2 product PGE
2
and PGI
2
analogues or the COX substrate arachidonic acid, suggesting that it was mediated by endogenous prostanoids produced by COX-2. Consistent with this, IL-1β, BK, and TGF-β
1
all induced COX-2 and PGE
2
release. These results show that BK, IL-1β, and TGF-β
1
downregulate adenylyl cyclase in human pulmonary artery smooth muscle cells via COX-2 induction and prostanoid release. This suggests a novel mechanism whereby mediators and cytokines produced in pulmonary hypertension may impair the therapeutic effects of prostacyclin analogues such as iloprost and carbaprostacyclin.
Prevention and Reversal of Premature Endothelial Cell Senescence and Vasculopathy in Obesity-Induced Diabetes by Ebselen
Authors: Brodsky Sergey V. , Gealekman Olga , Chen Jun , Zhang Fan , Togashi Nobuhiko , Crabtree Mark , Gross Steven S. , Nasjletti Alberto , Goligorsky Michael S.
Published: December 2003

Although the accelerated atherosclerosis and premature aging of the cardiovascular system in patients with metabolic syndrome have been appreciated, the mechanisms of their development and potential therapeutic interventions remain unresolved. Our previous studies implicated advanced glycosylation end products in development of premature senescence preventable with a peroxynitrite scavenger, ebselen. Therefore, the effect of ebselen on endothelial senescence and vasculopathy in a model of metabolic syndrome—Zucker diabetic rats (ZDF)—was investigated. Ebselen decreased the abundance of 3-nitrotyrosine–modified proteins in ZDF rats. A 6-fold increase in the number of senescent endothelial cells in 22-week-old ZDF was prevented by ebselen. Development of vasculopathy, as collectively judged by the acetylcholine-induced vasorelaxation, NO production, angiogenic competence, and number of circulating microparticles, was almost completely prevented when ebselen was administered from 8 to 22 weeks and partially reversed when the treatment interval was 13 to 22 weeks. In conclusion, premature senescence of endothelial cells is progressively rampant in ZDF rats and is associated with the signs of severe vasculopathy. In addition, prevention of premature senescence of vascular endothelium through controlled decrease in nitrotyrosine formation was chronologically associated with the amelioration of vasculopathy, lending support to the idea of the pathogenetic role of premature senescence of endothelial cells in diabetic macrovasculopathy.
Specific Induction of
tie1
Promoter by Disturbed Flow in Atherosclerosis-Prone Vascular Niches and Flow-Obstructing Pathologies
Authors: Porat Rinnat M. , Grunewald Myriam , Globerman Anat , Itin Ahuva , Barshtein Gregory , Alhonen Leena , Alitalo Kari , Keshet Eli
Published: December 2003

Nonlaminar flow is a major predisposing factor to atherosclerosis. Yet little is known regarding hemodynamic gene regulation in disease-prone areas of the vascular tree in vivo. We have determined spatial patterns of expression of endothelial cell receptors in the arterial tree and of reporter gene constructs in transgenic animals. In this study we show that the endothelial cell–specific receptor Tie1 is induced by disturbed flow in atherogenic vascular niches. Specifically,
tie1
expression in the adult is upregulated in vascular bifurcations and branching points along the arterial tree. It is often confined to a single ring of endothelial cells functioning as sphincters and hence experiencing the steepest gradient in shear stress. In aortic valves,
tie1
is asymmetrically induced only in endothelial cells encountering changes in flow direction. Disturbance of laminar flow by a surgical interposition of a vein into an artery led to induction of
tie1
, specifically in the region where the differently sized vessels adjoin. In pathological settings,
tie1
expression is specifically induced in areas of disturbed flow because of the emergence of aneurysms and, importantly, in endothelial cells precisely overlying atherosclerotic plaques. Hemodynamic features of atherosclerotic lesion-prone regions, recreated in vitro with the aid of a flow chamber with a built-in step, corroborated an upregulated
tie1
promoter activity only in cells residing where flow separation and recirculation take place. These defined promoter elements might be harnessed for targeting gene expression to atherosclerotic lesions.
Long-Term Treatment With a Rho-Kinase Inhibitor Improves Monocrotaline-Induced Fatal Pulmonary Hypertension in Rats
Authors: Abe Kohtaro , Shimokawa Hiroaki , Morikawa Keiko , Uwatoku Toyokazu , Oi Keiji , Matsumoto Yasuharu , Hattori Tsuyoshi , Nakashima Yutaka , Kaibuchi Kozo , Sueishi Katsuo , Takeshit Akira
Published: December 2003

Primary pulmonary hypertension is a fatal disease characterized by endothelial dysfunction, hypercontraction and proliferation of vascular smooth muscle cells (VSMCs), and migration of inflammatory cells, for which no satisfactory treatment has yet been developed. We have recently demonstrated that intracellular signaling pathway mediated by Rho-kinase, an effector of the small GTPase Rho, is involved in the pathogenesis of arteriosclerosis. In the present study, we examined whether the Rho-kinase–mediated pathway is also involved in the pathogenesis of fatal pulmonary hypertension in rats. Animals received a subcutaneous injection of monocrotaline, which resulted in the development of severe pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions in 3 weeks associated with subsequent high mortality rate. The long-term blockade of Rho-kinase with fasudil, which is metabolized to a specific Rho-kinase inhibitor hydroxyfasudil after oral administration, markedly improved survival when started concomitantly with monocrotaline and even when started after development of pulmonary hypertension. The fasudil treatment improved pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular lesions with suppression of VSMC proliferation and macrophage infiltration, enhanced VSMC apoptosis, and amelioration of endothelial dysfunction and VSMC hypercontraction. These results indicate that Rho-kinase–mediated pathway is substantially involved in the pathogenesis of pulmonary hypertension, suggesting that the molecule could be a novel therapeutic target for the fatal disorder.
Thrombin- and Factor Xa–Induced DNA Synthesis Is Mediated by Transactivation of Fibroblast Growth Factor Receptor-1 in Human Vascular Smooth Muscle Cells
Authors: Rauch Bernhard H. , Millette Esther , Kenagy Richard D. , Daum Guenter , Clowes Alexander W.
Published: December 2003

Thrombin and factor Xa (FXa) are agonists for G protein–coupled receptors (GPRCs) and may contribute to vascular lesion formation by stimulating proliferation of vascular smooth muscle cells (SMCs). Mitogenic signaling of GPCRs requires transactivation of receptor tyrosine kinases (RTKs). In rat SMCs, thrombin transactivates the epidermal growth factor receptor (EGFR) via a pathway that involves heparin-binding EGF-like growth factor (HB-EGF) as ligand for EGFR. The purpose of this study was to investigate in human SMCs the role of receptor transactivation in the mitogenic response to thrombin and FXa. Thrombin (10 nmol/L) and FXa (100 nmol/L) cause a 3.3- and 2.6-fold increase in DNA synthesis, respectively. In human SMCs, neither thrombin nor FXa causes EGFR phosphorylation, and blockade of EGFR kinase does not inhibit DNA synthesis. However, DNA synthesis and phosphorylation of fibroblast growth factor receptor-1 (FGFR-1) induced by thrombin or FXa are inhibited by antibodies neutralizing basic fibroblast growth factor (bFGF) or by heparin. Hirudin inhibits thrombin-, but not FXa-induced mitogenesis, indicating that FXa acts independently of thrombin. We further demonstrate by ELISA that upon thrombin and FXa stimulation, bFGF is released and binds to the extracellular matrix. Our data suggest that in human vascular SMCs, both thrombin and FXa rapidly release bFGF into the pericellular matrix. This is followed by transactivation of the FGFR-1 and increased proliferation. Heparin may inhibit the mitogenic effects of thrombin and FXa in human SMCs by preventing bFGF binding to FGFR-1.
Early Growth Response-1 Promotes Atherogenesis
Authors: Harja Evis , Bucciarelli Loredana G. , Lu Yan , Stern David M. , Zou Yu Shan , Schmidt Ann Marie , Yan Shi-Fang
Published: December 2003

Early growth response-1 (Egr-1) regulates expression of proinflammatory and procoagulant genes in acute cell stress. Experimental evidence suggested that Egr-1 transcripts were upregulated in human atherosclerotic plaques versus adjacent unaffected tissue. To test the impact of Egr-1 in chronic vascular stress, we examined its role in a murine model of atherosclerosis. Real-time PCR analysis of aortae retrieved from apoE
−/−
mice demonstrated increased Egr-1 transcripts in an age-dependent manner, compared with aortae retrieved from C57BL/6 control animals. Therefore, homozygous Egr-1
−/−
mice were bred into the apoE
−/−
background. Homozygous double-knockout mice (Egr-1
−/−
/apoE
−/−
) in the C57BL/6 background were maintained on normal chow diet. At age 14 and 24 weeks, atherosclerotic lesion area and complexity at the aortic root were strikingly decreased in mice deficient in both Egr-1 and apoE compared with mice deficient in apoE alone. In parallel, transcripts for genes regulating the inflammatory/prothrombotic response were diminished in Egr-1
−/−
/apoE
−/−
aortae versus apoE
−/−
. In vitro, oxidized low-density lipoprotein (OxLDL), a key factor inciting atherogenic mechanisms in the vasculature, upregulated Egr-1 expression in monocytes via the MEK-ERK1/2 pathway. We conclude that Egr-1 broadly regulates expression of molecules critically linked to atherogenesis and lesion progression.
Big Mitogen-Activated Protein Kinase (BMK1)/ERK5 Protects Endothelial Cells From Apoptosis
Authors: Pi Xinchun , Yan Chen , Berk Bradford C.
Published: December 2003

Blood flow that is steady and laminar is known to be atheroprotective. One likely mechanism is enhanced endothelial cell (EC) survival. Because the mitogen-activated protein kinases (MAPKs) are known regulators of cell survival, we investigated the role of Big MAPK-1 (BMK1 or ERK5), which is potently stimulated by fluid shear stress. To activate BMK1, we overexpressed constitutively active (CA)-MEK5 in bovine lung microvascular ECs (BLMECs). Cell apoptosis was induced by growth factor deprivation (0% serum for 24 hours). Analysis of cell viability with MTT assay showed that activation of BMK1 by CA-MEK5 significantly improved cell viability from 48% to 87% and decreased apoptotic cells from 49% to 10%. Growth factor deprivation induced caspase-3 activity 5.2-fold, which was inhibited (≈60%) by CA-MEK5 overexpression. In contrast, inhibiting BMK1 activity by overexpressing dominant-negative BMK1 (DN-BMK1) stimulated apoptosis in BLMECs. Steady laminar fluid shear stress inhibited BLMEC apoptosis, and this protective effect was also reduced significantly by overexpressing DN-BMK1. Analysis of antiapoptotic mechanisms showed that both shear stress and CA-MEK5 stimulated phosphorylation of Bad on Ser112 and Ser136, whereas DN-BMK1 inhibited phosphorylation. Phosphorylation of Bad induced by BMK1 activation was independent of Akt, PKA, or p90RSK kinase activity. These results suggest that BMK1 activation by steady laminar flow is atheroprotective by inhibiting EC apoptosis via phosphorylation of Bad.
Novel Diagnostic Test for Acute Stroke
Authors: Lynch John R. , Blessing Robert , White William D. , Grocott Hilary P. , Newman Mark F. , Laskowitz Daniel T.
Published: December 2003

Background and Purpose—

The absence of a widely available and sensitive diagnostic test for acute cerebral ischemia remains a significant limitation in the diagnosis and management of stroke. The objective of this study was to examine the feasibility of developing a diagnostic panel of blood-borne biochemical markers of cerebral ischemia.

Methods—

Serial blood samples were obtained from patients (n=65 with suspected ischemic stroke, n=157 control subjects) presenting to an academic medical center emergency department. We analyzed 26 blood-borne markers believed to play a role in the ischemic cascade and created a 3-variable logistic regression model to predict the clinical diagnosis of stroke, defined as persistent neurological symptoms of cerebral ischemia lasting >24 hours.

Results—

Of the 26 blood-borne markers analyzed, univariate logistic analysis revealed that 4 were highly correlated with stroke (
P
<0.001): a marker of glial activation (S100β), 2 markers of inflammation (matrix metalloproteinase-9 and vascular cell adhesion molecule), and 1 marker of thrombosis (von Willebrand factor). When the outcome level was set to a cutoff of
P
=0.1, our logistic model provided a sensitivity and specificity of 90% for predicting stroke.

Conclusions—

A panel of blood-borne biochemical markers may be helpful in identifying patients with acute cerebral ischemia who could benefit from urgent care. Such a test may also be helpful in identifying stroke patients in the prehospital setting so that they could be fast-tracked to an institution equipped to care for patients with acute stroke.
William M. Feinberg Lecture: Stroke Therapy in the Year 2025
Authors: Broderick Joseph P.
Published: December 2003

Background—

More than 700 000 strokes occurred in the United States during 2002, of which approximately 500 000 are first-ever strokes and 200 000 recurrent strokes. If we would decrease the enormous burden of stroke throughout the world, we first need to know the barriers that we have to overcome. These are quite similar to the barriers that we have tried to surmount during the last 25 years.

Stroke Prevention—

We have developed many successful primary and secondary therapies to prevent stroke over the past 25 years and have begun to understand some of the genetic risk factors underlying stroke. Yet, the incidence rate of stroke in Rochester, Minn, remained unchanged from 1975 to the mid-1990s, and mortality rates for Ohio have changed little for men, women, blacks, and whites over the past decade. The primary reason that we have made little progress in decreasing the burden of stroke is that we have made little progress in modifying the primary risk factors for stroke in the population. Other barriers of improved stroke prevention in the future include costs of therapy and aging of blood vessels and brain, which is the most important risk factor for stroke.

Acute Stroke—

Breakthroughs in acute stroke treatment are likely to follow the steps of cardiology with the primary focus for ischemic stroke on the restoration of oxygenated blood flow to ischemic brain as quickly as possible.To improve acute stroke therapy in the year 2025, we need to have more focused messages sent to the lay public about stroke warning signs, better and safer methods to open arteries quickly, truly effective neuroprotection in the setting of reperfusion, regional organization for acute stroke therapy, and large randomized trials to find clinically important but smaller benefits. A scientifically proven treatment for treatment of acute intracerebral hemorrhage is another major goal.

Recovery After Stroke—

Brain recovery after stroke is the area of scientific discovery with the largest potential for advances far into the next century. Obstacles that block effective therapies in the recovery from stroke include the extent of initial injury from stroke, the brain plasticity of a given patient, and, most importantly, understanding the “neural code”—how the brain is organized and how cells communicate with one another.
Effects of a Perindopril-Based Blood Pressure–Lowering Regimen on the Risk of Recurrent Stroke According to Stroke Subtype and Medical History
Authors: Chapman N. , Huxley R. , Anderson C. , Bousser M.G. , Chalmers J. , Colman S. , Davis S. , Donnan G. , MacMahon S. , Neal B. , Warlow C. , Woodward M.
Published: December 2003

Background and Purpose—

The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) showed that blood pressure lowering reduced stroke risk in patients with a history of cerebrovascular events. Here, we report the consistency of treatment effects across different stroke subtypes and among major clinical subgroups.

Methods—

PROGRESS was a randomized, double-blind trial among 6105 people with a prior history of cerebrovascular events. Participants were assigned to active treatment (perindopril for all participants and indapamide for those with neither an indication for nor a contraindication to a diuretic) or matching placebo(s).

Results—

During a mean of 3.9 years of follow-up, active treatment reduced the absolute rates of ischemic stroke from 10% to 8% (relative risk reduction [RRR], 24%; 95% confidence interval [CI], 10 to 35) and the absolute rates of intracerebral hemorrhage from 2% to 1% (RRR, 50%; 95% CI, 26 to 67). The relative risk of any stroke during follow-up was reduced by 26% (95% CI, 12 to 38) among patients whose baseline cerebrovascular event was an ischemic stroke and by 49% (95% CI, 18 to 68) among those whose baseline event was an intracerebral hemorrhage. There was no evidence that treatment effects were modified by other drug therapies (antiplatelet or other antihypertensive agents), residual neurological signs, atrial fibrillation, or the time since the last cerebrovascular event.

Conclusions—

Beneficial effects of a perindopril-based treatment regimen were observed for all stroke types and all major clinical subgroups studied. These data suggest that effective blood pressure–lowering therapy should be routinely considered for all patients with a history of cerebrovascular events.
Effect of Incomplete (Spontaneous and Postthrombolytic) Recanalization After Middle Cerebral Artery Occlusion
Authors: Neumann-Haefelin T. , du Mesnil de Rochemont R. , Fiebach J.B. , Gass A. , Nolte C. , Kucinski T. , Rother J. , Siebler M. , Singer O.C. , Szabo K. , Villringer A. , Schellinger P.D.
Published: December 2003

Background and Purpose—

Early reperfusion is one of the best predictors of good outcome after acute middle cerebral artery (MCA) occlusion. The purpose of this study was to analyze the frequency and relevance of incomplete recanalization for tissue and clinical outcome.

Methods—

From a larger acute stroke database (Kompetenznetzwerk Schlaganfall B5), all patients (n=82) with MCA main stem occlusion (excluding carotid T-occlusions) were selected. These patients had received a multiparametric stroke MRI protocol including diffusion- and perfusion-weighted imaging (DWI, PWI) and MR angiography (MRA) within 6 hours after symptom onset, at day 1 and after 1 week. Recanalization status was determined with MRA on day 1 (according to Thrombolysis In Myocardial Infarction flow grades) and used to group patients into those with persistent occlusion (0) or minimal (1), partial (2), or complete (3) recanalization.

Results—

Incomplete recanalization according to MRI criteria was found in 39 patients (grade 1: n=20; grade 2: n=19), complete recanalization in 10, and persistent occlusion in 33. There was no statistically significant difference in any of the clinical (National Institutes of Health Stroke Scale score) or MRI baseline parameters (DWI lesion, PWI deficit, mismatch volume, mismatch ratio). However, lesion growth was smaller in patients with recanalization (even in patients with only minimal recanalization) and outcome was related to the degree of recanalization (mean modified Rankin score at 90 days: 3.36, 2.70, 1.79, and 1.44 for the groups with no, minimal, partial, and complete recanalization, respectively). Both incomplete and complete recanalization was more frequent in patients receiving thrombolysis.

Conclusions—

Incomplete recanalization on day 1 is a frequent MR finding after MCA main stem occlusion, indicating a more favorable clinical course than persistent occlusion. MR indicators of early recanalization could be useful surrogates of efficacy in thrombolytic trials.
Improving the Predictive Accuracy of Recanalization on Stroke Outcome in Patients Treated With Tissue Plasminogen Activator
Authors: Molina Carlos A. , Alexandrov Andrei V. , Demchuk Andrew M. , Saqqur Maher , Uchino Ken , Alvarez-Sabín José
Published: December 2003

Background and Purpose—

Although early recanalization is a powerful predictor of stroke outcome after thrombolysis, some stroke patients remain disabled despite tissue plasminogen activator (tPA)–induced recanalization. Therefore, we sought to investigate whether the predictive accuracy of early recanalization on stroke outcome is improved when combined with clinical and radiological information.

Methods—

We evaluated 177 patients with nonlacunar strokes in the middle cerebral artery (MCA) treated with intravenous tPA who were followed up during 3 months. Transcranial Doppler monitoring of recanalization was conducted during the first hours after tPA administration. The relative contribution of clinical, transcranial Doppler, and radiological information on stroke outcome was evaluated. We used logistic regression to derive a predictive model for good outcome (modified Rankin Scale score ≤2) after thrombolysis.

Results—

Median National Institutes of Health Stroke Scale (NIHSS) score before tPA was 16. At 3 months, 87 patients (49.2%) became functionally independent (modified Rankin Scale score ≤2). In a logistic regression model, degree of recanalization within 300 minutes (
P
<0.001), proximal MCA occlusion (
P
<0.001), baseline NIHSS score (
P
=0.0013), systolic blood pressure (
P
=0.0116), and early ischemic changes on CT (
P
=0.0253) independently predicted outcome at 3 months. A 5-item score was developed on the basis of the factors significantly associated with stroke outcome in the logistic regression (total score range, 0 to 7). The likelihood of good outcome at 3 months was 0.82 (95% CI, 0.72 to 0.92) in patients who scored 0 to 2, 0.51 (95% CI, 0.36 to 0.66) in those who scored 3 to 4, and 0.15 (95% CI, 0.05 to 0.25) in those who scored 5 to 7 points.

Conclusions—

The combination of clinical, radiological, and hemodynamic information predicts with a high accuracy long-term stroke outcome during or shortly after intravenous tPA administration.
Folate, Vitamin B
6
, and B
12
Intakes in Relation to Risk of Stroke Among Men
Authors: He Ka , Merchant Anwar , Rimm Eric B. , Rosner Bernard A. , Stampfer Meir J. , Willett Walter C. , Ascherio Alberto
Published: December 2003

Background and Purpose—

Folate, vitamin B
6
, and B
12
deficiency are related to elevated blood homocysteine level. However, the effects of intakes of these vitamins on risk of stroke are still uncertain. This study examines intakes of folate, vitamin B
6
, and B
12
in relation to risk of ischemic and hemorrhagic stroke.

Methods—

We enrolled 43 732 men, aged 40 to 75 years, who were free of cardiovascular diseases and diabetes at baseline. Participants were followed from 1986 to 2000. Dietary information was assessed every 4 years using a detailed and validated semiquantitative food frequency questionnaire. The main outcome measures were incident ischemic and hemorrhagic strokes.

Results—

A total of 725 incident strokes, including 455 ischemic, 125 hemorrhagic, and 145 unknown types of stroke, were documented during the 14-year follow-up. After adjustment for major lifestyle and dietary factors, intake of folate was associated with a significantly lower risk of ischemic but not hemorrhagic stroke. The multivariate relative risk of ischemic stroke was 0.71 (95% CI, 0.52 to 0.96;
P
for trend=0.05) for men in the highest quintile of intake compared with those who in the lowest quintile. Intake of vitamin B
12
, but not B
6
, was also inversely associated with risk of ischemic stroke.

Conclusions—

Our findings suggest that increased folate intake is associated with decreased risk of ischemic stroke in men.
Direction of Flow in Posterior Communicating Artery on Magnetic Resonance Angiography in Patients With Occipital Lobe Infarcts
Authors: Jongen Jacqueline C.F. , Franke Cees L. , Ramos Lino M.P. , Wilmink Jan T. , van Gijn Jan
Published: December 2003

Background and Purpose—

In some people the blood supply to the posterior cerebral artery occurs partly or even exclusively via the carotid system. This anatomic configuration may influence the risk of occipital lobe infarction. We studied the presence and direction of flow in the posterior communicating artery (PCoA) in patients with an occipital lobe infarct and in healthy controls.

Methods—

Forty-seven patients with an occipital lobe infarct were studied by MR angiography, as well as 50 young healthy controls. Special attention was paid to the presence of a PCoA and, if present, to the direction of flow.

Results—

Significantly fewer patients than controls had an exclusive blood supply to the posterior cerebral artery via the carotid system, in both the affected (4% versus 17%; 95% CI of difference, 4% to 22%) and unaffected hemispheres (5% versus 17%; 95% CI of difference, 3% to 22%). Patients also less often had a patent PCoA with anteroposterior flow than controls (affected hemisphere, 8% versus 22%; unaffected hemisphere, 12% versus 22%; 95% CI of differences, 3% to 25% and −2% to 23%, respectively). With analysis at the level of individuals, significantly more patients showed no anteroposterior flow through the PCoA in either hemisphere than controls (79% versus 42%; 95% CI of difference, 19% to 55%).

Conclusions—

Supply of the posterior cerebral artery by the carotid system occurs less often in patients with an occipital lobe infarct than in healthy controls. The same was true for the unaffected hemisphere of patients, which suggests that the anatomic difference represents a causal factor (fewer collateral pathways after occlusion of the posterior cerebral artery or its branches) rather than a consequence (redistribution of blood flow after occipital infarction).
A Common Polymorphism of the Protein Z Gene Is Associated With Protein Z Plasma Levels and With Risk of Cerebral Ischemia in the Young
Authors: Lichy C. , Kropp S. , Dong-Si T. , Genius J. , Dolan T. , Hampe T. , Stoll F. , Reuner K. , Grond-Ginsbach C. , Grau A.
Published: December 2003

Background and Purpose—

The vitamin K–dependent protein Z (PZ) has been shown to possess anticoagulant as well as procoagulant properties. Plasma levels of PZ show a broad interindividual variation, but it is unknown to which extent this variation is under genetic control. Recent clinical studies revealed contradictory results on the association of PZ plasma levels and the risk of ischemic stroke.

Methods—

We performed a case-control study including 200 patients with cerebral ischemia aged ≤50 years and 199 control subjects from the same South German region. We investigated a possible association of 2 common single nucleotide mutations in the PZ gene with the risk of cerebral ischemia. Furthermore, enzyme-linked immunosorbent assay measurements were done in control subjects without vascular disease to detect a potential association of different genotypes with PZ plasma (antigen) levels.

Results—

In patients, the frequency of the A allele of the intron F polymorphism G79A was significantly lower than in controls (15.7% versus 24.4%; odds ratio, 0.58; 95% CI, 0.39 to 0.86;
P
=0.007; adjusted for age, sex, and conventional risk factors). The G allele of the promoter polymorphism A-13G tended to be less common in patients (4.2% versus 7.0%; adjusted odds ratio, 0.56; 95% CI, 0.28 to 1.13;
P
=0.105). In 42 control subjects, the A allele of the intron F polymorphism was associated with lower PZ antigen levels (
P
=0.0032; Spearman correlation coefficient
r
s
=−0.48).

Conclusions—

The A allele of an intron F polymorphism of the PZ gene appears to be a novel protective genetic marker for the risk of cerebral ischemia in young adults. In the context of juvenile stroke, high PZ plasma levels may represent a prothrombotic condition.
Randomized Controlled Trial of an Early Discharge Rehabilitation Service
Authors: Donnelly Michael , Power Michael , Russell Mary , Fullerton Ken
Published: December 2003

Background and Purpose—

To compare a community-based multidisciplinary stroke team (CST) approach with hospital-based rehabilitation in terms of hospital stay, functioning, quality of life, and service use and costs.

Methods—

Stroke patients who met pre-agreed criteria were allocated randomly to the CST service (n=59) or to usual inpatient rehabilitation and follow-up care (n=54). Assessments were completed at randomization and 12 months later. Caregiver strain and satisfaction (n=55) were also assessed. Cost data were collected for a subsample of 38 patients.

Results—

Almost 80% of surviving patients (n=691) were discharged home and a small number (n=55) were readmitted. Approximately 17% (113/649) were randomized. There were no statistically significant differences in hospital duration, costs, or outcome measures at baseline and 12 months except for higher satisfaction reported by CST patients. Overall, both groups recorded improvement in most domains over time. Carers reported a high level of satisfaction although the level of strain among carers is cause for concern. The community group (n=18) cost less than the hospital group (n=20).

Conclusions—

A mixed model of hospital-based and community-based rehabilitation services is likely to lead to increased patient choice and satisfaction and a potential reduction in bed pressures for less severe stroke patients.
Clinicotopographical Correlation of Corticospinal Tract Stroke
Authors: Lie C. , Hirsch J.G. , Roßmanith C. , Hennerici M.G. , Gass A.
Published: December 2003

Background—

Small capsular strokes are difficult to assess with regard to the precise location and the extent of pyramidal tract damage with conventional brain imaging. Color-coded diffusion tensor imaging (CDTI) provides a means to visualize the course of the corticospinal tract within the white matter. In addition to T
2
-weighted MRI, diffusion-weighted MRI and CDTI were used to analyze the topographical patterns of small lacunar corticospinal tract strokes.

Methods—

We examined 15 patients with pyramidal tract strokes in the subacute phase (days 3 to 7). Lesions were identified on diffusion-weighted MRI and superimposed on CDTI images. The anatomic location and pattern of the lesion were visualized on CDTI with regard to the corticospinal tract and subsequently compared with the clinical presentation. In addition, infarct areas were evaluated with quantitative parameters: mean diffusivity and lattice anisotropy index of lesions were determined.

Results—

We identified 5 different patterns of corticospinal tract stroke falling into 2 clinical subgroups: (1) those with marked deficits and minor improvement (6/15) and (2) those with good recovery (9/15). Group 1 had long lesions centered in the pyramidal tract, involving the basal ganglia (anterior choroidal artery); group 2 lesions were very small and/or located anteriorly and medially (periventricular anterior choroidal artery territory; thalamogeniculate, tuberothalamic, and lateral striate branches). Lesions showed a significant increase of mean diffusivity and decrease of lattice anisotropy.

Conclusion—

CDTI allows in vivo differentiation of distinct subcortical stroke subtypes. Improved anatomic definition of lesion localization using CDTI may help in better establishing the prognosis for patients after subcortical stroke.