bluuebunny/crossref_metadata_2025 huggingface dataset:
Therapeutic Reendothelialization by Induced Pluripotent Stem Cells After Vascular Injury—Brief Report
Authors: Yamamoto Takashi , Shibata Rei , Ishii Masakazu , Kanemura Noriyoshi , Kito Tetsutaro , Suzuki Hirohiko , Miyake Hiroshi , Maeda Kengo , Tanigawa Tohru , Ouchi Noriyuki , Murohara Toyoaki
Published: July 2013

Objective—

Endothelial damage is an early requisite step for atherosclerosis after vascular injury. It has been reported that vascular wall cells can develop from induced pluripotent stem (iPS) cell–derived fetal liver kinase-1–positive (Flk-1
+
) cells. Here, we investigated the efficacies of intravenously administered iPS cell–derived Flk-1
+
cells on reendothelialization and neointimal hyperplasia in a mouse model of vascular injury.

Approach and Results—

Femoral arteries of KSN nude mice were injured using a steel wire. Mouse iPS cell–derived Flk-1
+
or Flk-1
−
cells were intravenously injected into those mice at 24 hours after vascular injury. Delivery of iPS cell–derived Flk-1
+
cells significantly attenuated neointimal hyperplasia compared with controls. Evans blue staining of the injured vessel revealed that administration of iPS cell–derived Flk-1
+
significantly enhanced reendothelialization compared with the Flk-1
−
cell control group. Recruitment of PKH26-labeled iPS cell–derived Flk-1
+
cells to the site of injury was also detectable. Expression level of CXCR4 in iPS cell–derived Flk-1
+
cells was 7.5-fold higher than that of iPS cell–derived Flk-1
−
cells. Stromal cell-derived factor-1α treatment significantly enhanced adhesion and migration of iPS cell–derived Flk-1
+
cells to the endothelia, but these were not observed in Flk-1
−
cells.

Conclusions—

Intravenously administered iPS cell–derived Flk-1
+
cells are recruited to the site of vascular injury, thereby enhancing reendothelialization followed by suppression of neointimal hyperplasia. Administration of iPS cell–derived Flk-1
+
cells is a potentially useful therapeutic means for vascular dysfunction and prevention of restenosis after angioplasty.
Induction of ATF3 Gene Network by Triglyceride-Rich Lipoprotein Lipolysis Products Increases Vascular Apoptosis and Inflammation
Authors: Aung Hnin H. , Lame Michael W. , Gohil Kishorchandra , An Chung-Il , Wilson Dennis W. , Rutledge John C.
Published: July 2013

Objective—

Elevation of triglyceride-rich lipoproteins (TGRLs) contributes to the risk of atherosclerotic cardiovascular disease. Our work has shown that TGRL lipolysis products in high physiological to pathophysiological concentrations cause endothelial cell injury; however, the mechanisms remain to be delineated.

Approach and Results—

We analyzed the transcriptional signaling networks in arterial endothelial cells exposed to TGRL lipolysis products. When human aortic endothelial cells in culture were exposed to TGRL lipolysis products, activating transcription factor 3 (ATF3) was identified as a principal response gene. Induction of ATF3 mRNA and protein was confirmed by quantitative reverse-transcription polymerase chain reaction and Western blot respectively. Immunofluorescence analysis showed that ATF3 accumulated in the nuclei of cells treated with lipolysis products. Nuclear expression of phosphorylated c-Jun N-terminal kinase (JNK), previously shown to be an initiator of the ATF3 signaling cascade, also was demonstrated. Small interfering RNA (siRNA)–mediated inhibition of ATF3 blocked lipolysis products–induced transcription of E-selectin and interleukin-8, but not interleukin-6 or nuclear factor-κB. c-Jun, a downstream protein in the JNK pathway, was phosphorylated, whereas expression of nuclear factor-κB–dependent JunB was downregulated. Additionally, JNK siRNA suppressed ATF3 and p-c-Jun protein expression, suggesting that JNK is upstream of the ATF3 signaling pathway. In vivo studies demonstrated that infusion of TGRL lipolysis products into wild-type mice induced nuclear ATF3 accumulation in carotid artery endothelium. ATF3
−/−
mice were resistant to vascular apoptosis precipitated by treatment with TGRL lipolysis products. Also peripheral blood monocytes isolated from postprandial humans had increased ATF3 expression as compared with fasting monocytes.

Conclusions—

This study demonstrates that TGRL lipolysis products activate ATF3-JNK transcription factor networks and induce endothelial cells inflammatory response.
Cardioprotective Effects of Exenatide in Patients With ST-Segment–Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention
Authors: Woo Jong Shin , Kim Weon , Ha Sang Jin , Kim Jin Bae , Kim Soo-Joong , Kim Woo-Shik , Seon Hyun Ju , Kim Kwon Sam
Published: July 2013

Objective—

Experimental evidence suggests that exenatide, a glucagon-like peptide 1 receptor analogue, has significant cardiovascular protective effects in various conditions. We examined whether routine use of exenatide at the time of primary percutaneous coronary intervention would reduce infarct size in patients with ST-segment–elevation myocardial infarction.

Approach and Results—

Fifty-eight patients with ST-segment–elevation myocardial infarction and thrombolysis in myocardial infarction flow 0 were enrolled in the study and randomly assigned to receive either exenatide or placebo (saline) subcutaneously. Infarct size was assessed by measuring the release of creatine kinase-MB and troponin I during 72 hours and by performing cardiac magnetic resonance imaging at 1 month after infarction. Routine and speckle tracking echocardiography was performed at initial presentation and at 3 days and 6 months after primary percutaneous coronary intervention. The exenatide and control groups had similar results with respect to ischemia time, demographic characteristics, and ejection fraction before primary percutaneous coronary intervention. The releases of creatine kinase-MB and troponin I were significantly reduced in the exenatide group. In 58 patients evaluated with cardiac magnetic resonance, the absolute mass of delayed hyperenhancement was significantly reduced in the exenatide group as compared with the control group (12.8±11.7 versus 26.4±11.6 g;
P
<0.01). At 6 months, the exenatide group showed a significantly lower value of
E
/
E
′ with improved strain parameters. No significant adverse effects of exenatide administration were detected.

Conclusions—

In patients with ST-segment–elevation myocardial infarction, adjunctive exenatide therapy with primary percutaneous coronary intervention was associated with reduction of infarct size and improvement of subclinical left ventricular function.
Aortic Remodeling After Transverse Aortic Constriction in Mice Is Attenuated With AT
1
Receptor Blockade
Authors: Kuang Shao-Qing , Geng Liang , Prakash Siddharth K. , Cao Jiu-Mei , Guo Steven , Villamizar Carlos , Kwartler Callie S. , Peters Andrew M. , Brasier Allan R. , Milewicz Dianna M.
Published: July 2013

Objective—

Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of angiotensin II type 1 receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model.

Approach and Results—

Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation and thickening of the medial and adventitial layers of the aorta. There was significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density attributable to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC-induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC-induced adventitial hyperplasia, collagen accumulation, and ascending aortic dilatation. Increased
Tgfb2
expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas were effectively blocked with losartan. In contrast, the increased
Tgfb1
expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked extracellular signal–regulated kinase activation and reactive oxygen species production in the TAC ascending aorta.

Conclusions—

Inhibition of the angiotensin II type 1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased transforming growth factor-β1 expression, adventitial Smad2 signaling, and collagen accumulation. These results help to delineate the aortic transforming growth factor-β signaling that is dependent and independent of the angiotensin II type 1 receptor after TAC.
Toll-Like Receptor 2/6 Agonist Macrophage-Activating Lipopeptide-2 Promotes Reendothelialization and Inhibits Neointima Formation After Vascular Injury
Authors: Grote Karsten , Sonnenschein Kristina , Kapopara Piyushkumar R. , Hillmer Anja , Grothusen Christina , Salguero Gustavo , Kotlarz Daniel , Schuett Harald , Bavendiek Udo , Schieffer Bernhard
Published: July 2013

Objective—

Reendothelialization after vascular injury (ie, balloon angioplasty or stent implantation) is clinically extremely relevant to promote vascular healing. We here investigated the therapeutic potential of the toll-like receptor 2/6 agonist macrophage-activating lipopeptide (MALP)-2 on reendothelialization and neointima formation in a murine model of vascular injury.

Approach and Results—

The left common carotid artery was electrically injured, and reendothelialization was quantified by Evans blue staining after 3 days. A single injection of MALP-2 (1 or 10 µg, IV) after vascular injury accelerated reendothelialization (
P
<0.001). Proliferation of endothelial cells at the wound margins determined by 5-ethynyl-2′-deoxyuridine incorporation was significantly higher in MALP-2–treated animals (
P
<0.05). Furthermore, wire injury–induced neointima formation of the left common carotid artery was completely prevented by a single injection of MALP-2 (10 µg, IV). In vitro, MALP-2 induced proliferation (BrdU incorporation) and closure of an artificial wound of endothelial cells (
P
<0.05) but not of smooth muscle cells. Protein array and ELISA analysis of isolated primary endothelial cells and ex vivo stimulated carotid segments revealed that MALP-2 stimulated the release of multiple growth factors and cytokines predominantly from endothelial cells. MALP-2 induced a strong activation of the mitogen-activated protein kinase cascade in endothelial cells, which was attenuated in smooth muscle cells. Furthermore, MALP-2 significantly enhanced circulating monocytes and hematopoietic progenitor cells.

Conclusions—

The toll-like receptor 2/6 agonist MALP-2 promotes reendothelialization and inhibits neointima formation after experimental vascular injury via enhanced proliferation and migration of endothelial cells. Thus, MALP-2 represents a novel therapeutic option to accelerate reendothelialization after vascular injury.
Prospective Randomized Study to Assess the Efficacy of Site and Rate of Atrial Pacing on Long-Term Progression of Atrial Fibrillation in Sick Sinus Syndrome
Authors: Lau Chu-Pak , Tachapong Ngarmukos , Wang Chun-Chieh , Wang Jing-feng , Abe Haruhiko , Kong Chi-Woon , Liew Reginald , Shin Dong-Gu , Padeletti Luigi , Kim You-Ho , Omar Razali , Jirarojanakorn Kreingkrai , Kim Yoon-Nyun , Chen Mien-Cheng , Sriratanasathavorn Charn , Munawar Muhammad , Kam Ruth , Chen Jan-Yow , Cho Yong-Keun , Li Yi-Gang , Wu Shu-Lin , Bailleul Christophe , Tse Hung-Fat
Published: July 2013

Background—

Atrial-based pacing is associated with lower risk of atrial fibrillation (AF) in sick sinus syndrome compared with ventricular pacing; nevertheless, the impact of site and rate of atrial pacing on progression of AF remains unclear. We evaluated whether long-term atrial pacing at the right atrial (RA) appendage versus the low RA septum with (ON) or without (OFF) a continuous atrial overdrive pacing algorithm can prevent the development of persistent AF.

Methods and Results—

We randomized 385 patients with paroxysmal AF and sick sinus syndrome in whom a pacemaker was indicated to pacing at RA appendage ON (n=98), RA appendage OFF (n=99), RA septum ON (n=92), or RA septum OFF (n=96). The primary outcome was the occurrence of persistent AF (AF documented at least 7 days apart or need for cardioversion). Demographic data were homogeneous across both pacing site (RA appendage/RA septum) and atrial overdrive pacing (ON/OFF). After a mean follow-up of 3.1 years, persistent AF occurred in 99 patients (25.8%; annual rate of persistent AF, 8.3%). Alternative site pacing at the RA septum versus conventional RA appendage (hazard ratio=1.18; 95% confidence interval, 0.79–1.75;
P
=0.65) or continuous atrial overdrive pacing ON versus OFF (hazard ratio=1.17; 95% confidence interval, 0.79–1.74;
P
=0.69) did not prevent the development of persistent AF.

Conclusions—

In patients with paroxysmal AF and sick sinus syndrome requiring pacemaker implantation, an alternative atrial pacing site at the RA septum or continuous atrial overdrive pacing did not prevent the development of persistent AF.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00419640.
In-Hospital Risk Prediction for Post-stroke Depression
Authors: de Man-van Ginkel Janneke M. , Hafsteinsdóttir Thóra B. , Lindeman Eline , Ettema Roelof G.A. , Grobbee Diederick E. , Schuurmans Marieke J.
Published: July 2013

Background and Purpose—

The timely detection of post-stroke depression is complicated by a decreasing length of hospital stay. Therefore, the Post-stroke Depression Prediction Scale was developed and validated. The Post-stroke Depression Prediction Scale is a clinical prediction model for the early identification of stroke patients at increased risk for post-stroke depression.

Methods—

The study included 410 consecutive stroke patients who were able to communicate adequately. Predictors were collected within the first week after stroke. Between 6 to 8 weeks after stroke, major depressive disorder was diagnosed using the Composite International Diagnostic Interview. Multivariable logistic regression models were fitted. A bootstrap-backward selection process resulted in a reduced model. Performance of the model was expressed by discrimination, calibration, and accuracy.

Results—

The model included a medical history of depression or other psychiatric disorders, hypertension, angina pectoris, and the Barthel Index item dressing. The model had acceptable discrimination, based on an area under the receiver operating characteristic curve of 0.78 (0.72–0.85), and calibration (
P
value of the
U-
statistic, 0.96). Transforming the model to an easy-to-use risk-assessment table, the lowest risk category (sum score, <−10) showed a 2% risk of depression, which increased to 82% in the highest category (sum score, >21).

Conclusions—

The clinical prediction model enables clinicians to estimate the degree of the depression risk for an individual patient within the first week after stroke.
Physical Activity Frequency and Risk of Incident Stroke in a National US Study of Blacks and Whites
Authors: McDonnell Michelle N. , Hillier Susan L. , Hooker Steven P. , Le Anh , Judd Suzanne E. , Howard Virginia J.
Published: July 2013

Background and Purpose—

Regular physical activity (PA) is an important recommendation for stroke prevention. We compared the associations of self-reported PA with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study.

Methods—

REGARDS recruited 30 239 US blacks (42%) and whites, aged ≥45 years with follow-up every 6 months for stroke events. Excluding those with prior stroke, analysis involved 27 348 participants who reported their frequency of moderate to vigorous intensity PA at baseline according to 3 categories: none (physical inactivity), 1 to 3×, and ≥4× per week. Stroke and transient ischemic attack cases were identified during an average of 5.7 years of follow-up. Cox proportional hazards models were constructed to examine whether self-reported PA was associated with risk of incident stroke.

Results—

Physical inactivity was reported by 33% of participants and was associated with a hazard ratio of 1.20 (95% confidence intervals, 1.02–1.42;
P
=0.035). Adjustment for demographic and socioeconomic factors did not affect hazard ratio, but further adjustment for traditional stroke risk factors (diabetes mellitus, hypertension, body mass index, alcohol use, and smoking) partially attenuated this risk (hazard ratio, 1.14 [0.95–1.37];
P
=0.17). There was no significant association between PA frequency and risk of stroke by sex groups, although there was a trend toward increased risk for men reporting PA 0 to 3× a week compared with ≥4× a week.

Conclusions—

Self-reported low PA frequency is associated with increased risk of incident stroke. Any effect of PA is likely to be mediated through reducing traditional risk factors.
Natural History of Unruptured Intracranial Aneurysms
Authors: Juvela Seppo , Poussa Kristiina , Lehto Hanna , Porras Matti
Published: July 2013

Background and Purpose—

Unruptured intracranial aneurysms are increasingly being detected and are a notable healthcare burden. We investigated the long-term natural history of unruptured intracranial aneurysms and risk factors predictive of subsequent rupture.

Methods—

A total of 142 patients with 181 unruptured intracranial aneurysms diagnosed between 1956 and 1978, when these were not treated, were followed up until death or subarachnoid hemorrhage, or until 2011 to 2012. Annual and cumulative incidences of aneurysm rupture and risk factors for rupture were studied using Kaplan–Meier survival analysis and Cox proportional hazards regression models.

Results—

The median follow-up time was 21.0 (range, 0.8–52.3) years. During 3064 person-years, there were 34 first episodes of aneurysm rupture, giving an average annual incidence of 1.1%. Eighteen patients died on account of an initial or recurrent aneurysm rupture. The cumulative rate of bleeding was 10.5% (95% confidence interval [CI], 5.2–15.8) at 10 years, 23.0% (95% CI, 15.4–30.6) at 20 years, and 30.1% (95% CI, 21.3–38.9) at 30 years. None of the index aneurysms bled after a follow-up of 25 years. Cigarette smoking (adjusted hazard ratio, 2.44; 95% CI, 1.02–5.88), location of the aneurysm in the anterior communicating artery (adjusted hazard ratio, 3.73; 95% CI, 1.23–11.36), patient age inversely (0.96 per year, 95% CI, 0.92–1.00) and aneurysm diameter ≥7 mm (adjusted hazard ratio, 2.60; 95% CI, 1.13–5.98) independently predicted subsequent aneurysm rupture, as did alcohol consumption (1.27 per 100 g/week; 95% CI, 1.05–1.53;
P
<0.05), but only in univariable analysis.

Conclusions—

Cigarette smoking, patient age inversely, and the size and location of the unruptured intracranial aneurysm seem to be risk factors for aneurysm rupture. The risk of bleeding decreases with a very long-term follow-up.
The Stroke Impact Scale
Authors: Jenkinson Crispin , Fitzpatrick Ray , Crocker Helen , Peters Michele
Published: July 2013

Background and Purpose—

The Stroke Impact Scale (SIS) covers 8 dimensions and a composite disability score. This study evaluates the SIS in the UK context, and develops a single index and an 8-item short form.

Methods—

Patients with a diagnosis of stroke were recruited through general practices in London and the North-West of England. Patients completed the SIS and the EQ-5D.

Results—

Internal consistency of the SIS dimensions and the disability score ranged from α 0.86 to 0.95. Complete data were available on 73 questionnaires (48.34%). Factor analysis suggested the 8 domains could be aggregated into a single index. A short-form SIS (SF-SIS) index was created by summing 1 item per dimension. Selected items were those that most highly correlated with their respective domain score (ρ ranged from 0.77–0.94,
P
<0.001). The SF-SIS index scores were highly correlated with those gained from the parent form (ρ=0.98;
P
<0.001). The correlation of the SIS index and SF-SIS index with the EQ-5D was identical (ρ=0.83;
P
<0.001). The disability score, whether scored from the dimensions of the SIS, or relevant items on the SF-SIS, were highly correlated (ρ=0.97;
P
<0.001).

Conclusions—

The SIS covers aspects of health, which are of importance to stroke patients, and the dimensions were found to have high levels of internal consistency in the UK context. The amount of incomplete data suggests that the length of the questionnaire may present a substantial patient burden. In comparison to the parent form the SF-SIS can accurately provide the disability score and overall index score with considerable brevity.
Systolic Blood Pressure During Acute Stroke Is Associated With Functional Status and Long-term Mortality in the Elderly
Authors: Weiss Avraham , Beloosesky Yichayaou , Kenett Ron S. , Grossman Ehud
Published: July 2013

Background and Purpose—

The prognostic value of blood pressure (BP) levels during acute stroke has not been adequately studied. Most studies do not use continuous BP measurements, and patients are followed only for a short period. We designed a study to assess, with 24-hour BP monitoring (24H BPM), the impact of BP levels during the first day of stroke, on the short-term functional status and long-term mortality in elderly patients.

Methods—

We studied 177 patients with acute stroke (89 men), mean age 84±6 years. BP was measured on admission and 24H BPM was recorded within 24 hours of admission. After 7 days, patients were assessed for functional status according to the modified Rankin Scale and were subsequently followed up for mortality ≤5 years (mean, 2.07±1.48).

Results—

After 7 days, functional status improved and modified Rankin Scale decreased from 4.2 to 3.7. Follow-up analysis disclosed that 71 patients (27 men and 44 women) had died. Mortality rate was higher in women (50% versus 30%;
P
<0.01) and in patients with a history of congestive heart failure. Only average systolic BP, recorded by 24H BPM, predicted short-term functional status and long-term mortality. Cox proportional hazards model analysis demonstrated that age, sex, congestive heart failure, and average systolic BP >160 mm Hg, recorded by 24H BPM, were associated with increased mortality.

Conclusions—

High systolic BP recorded by 24H BPM on the first day of stroke was found to be associated with unfavorable short-term functional status and long-term mortality in elderly patients.
Unilateral Versus Bilateral Upper Limb Training After Stroke
Authors: van Delden A. (Lex) E.Q. , Peper C. (Lieke) E. , Nienhuys Kirsten N. , Zijp Nienke I. , Beek Peter J. , Kwakkel Gert
Published: July 2013

Background and Purpose—

Unilateral and bilateral training protocols for upper limb rehabilitation after stroke represent conceptually contrasting approaches with the same ultimate goal. In a randomized controlled trial, we compared the merits of modified constraint-induced movement therapy, modified bilateral arm training with rhythmic auditory cueing, and a dose-matched conventional treatment. Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing targeted wrist and finger extensors, given their importance for functional recovery. We hypothesized that modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are superior to dose-matched conventional treatment.

Methods—

Sixty patients, between 1 to 6 months after stroke, were randomized over 3 intervention groups. The primary outcome measure was the Action Research Arm test, which was conducted before, directly after, and 6 weeks after intervention.

Results—

Although all groups demonstrated significant improvement on the Action Research Arm test after intervention, which persisted at 6 weeks follow-up, no significant differences in change scores on the Action Research Arm test were found between groups postintervention and at follow-up.

Conclusions—

Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are not superior to dose-matched conventional treatment or each other in improving upper limb motor function 1 to 6 months after stroke.

Clinical Trial Registration—

URL:
http://www.trialregister.nl
. Unique identifier: NTR1665.
Surgical Decompression for Space-Occupying Cerebral Infarction
Authors: Geurts Marjolein , van der Worp H. Bart , Kappelle L. Jaap , Amelink G. Johan , Algra Ale , Hofmeijer Jeannette
Published: July 2013

Background and Purpose—

We assessed whether the effects of surgical decompression for space-occupying hemispheric infarction, observed at 1 year, are sustained at 3 years.

Methods—

Patients with space-occupying hemispheric infarction, who were enrolled in the Hemicraniectomy After Middle cerebral artery infarction with Life-threatening Edema Trial within 4 days after stroke onset, were followed up at 3 years. Outcome measures included functional outcome (modified Rankin Scale), death, quality of life, and place of residence. Poor functional outcome was defined as modified Rankin Scale >3.

Results—

Of 64 included patients, 32 were randomized to decompressive surgery and 32 to best medical treatment. Just as at 1 year, surgery had no effect on the risk of poor functional outcome at 3 years (absolute risk reduction, 1%; 95% confidence interval, −21 to 22), but it reduced case fatality (absolute risk reduction, 37%; 95% confidence interval, 14–60). Sixteen surgically treated patients and 8 controls lived at home (absolute risk reduction, 27%; 95% confidence interval, 4–50). Quality of life improved between 1 and 3 years in patients treated with surgery.

Conclusions—

In patients with space-occupying hemispheric infarction, the effects of decompressive surgery on case fatality and functional outcome observed at 1 year are sustained at 3 years.

Clinical Trial Registration—

URL:
http://www.controlled-trials.com
. Unique identifier: ISRCTN94237756.
Arterial Spin–Labeled Perfusion Imaging to Predict Mismatch in Acute Ischemic Stroke
Authors: Niibo Takeya , Ohta Hajime , Yonenaga Kazuma , Ikushima Ichiro , Miyata Shirou , Takeshima Hideo
Published: July 2013

Background and Purpose—

We assigned a threshold to arterial spin–labeling (ASL) perfusion-weighted images (PWI) from patients with acute ischemic stroke and compared them with dynamic susceptibility contrast perfusion images to examine whether mismatch can be determined.

Methods—

Pseudocontinuous ASL was combined with dynamic susceptibility contrast PWI in 23 patients with acute ischemic stroke. Scans were obtained within 24 hours of symptom onset. PWI volumes were defined by ASL cerebral blood flow (<15, <20, and <25 mL/100 g per minute) and dynamic susceptibility contrast–mean transit time (MTT) thresholds (>10 s) that show a strong association with cerebral blood flow <20 mL/100 g per minute in Xenon CT studies. Agreement between the ASL–diffusion-weighted imaging and MTT–diffusion-weighted imaging mismatch and the correlation between penumbra salvage and infarct growth, defined as the difference between the baseline PWI and the baseline diffusion-weighted imaging lesion, respectively, and the final infarct volume were assessed.

Results—

The lesion volumes defined by MTT>10 s and ASL<20 mL/100 g per minute showed an excellent correlation. There was 100% agreement on the mismatch status between MTT>10 s and ASL<20 mL/100 g per minute. The correlation between infarct growth and penumbra salvage volume was significantly better for PWI lesions defined by ASL<20 mL/100 g per minute and MTT>10 s.

Conclusions—

In acute ischemic stroke, PWI lesions based on ASL threshold of <20 mL/100 g per minute can provide a reliable estimate of mismatch in correspondence at MTT threshold of >10 s.
Ideal Cardiovascular Health Metrics and the Risks of Ischemic and Intracerebral Hemorrhagic Stroke
Authors: Zhang Qian , Zhou Yong , Gao Xiang , Wang Chunxue , Zhang Shufeng , Wang Anxin , Li Na , Bian Liheng , Wu Jianwei , Jia Qian , Wu Shouling , Zhao Xingquan
Published: July 2013

Background and Purpose—

Previous studies showed an inverse association between ideal cardiovascular health (CVH) metrics and the total risk of cardiovascular diseases and stroke. This study aimed to investigate the relationship between ideal CVH metrics and the risks of ischemic and hemorrhagic stroke, respectively.

Methods—

We collected information on the 7 ideal CVH metrics (including smoking status, body mass index, dietary intake, physical activity, blood pressure, total cholesterol, and fasting blood glucose) among 91 698 participants from the Kailuan study, China (72 826 men and 18 872 women between the ages of 18 and 98 years), free of myocardial infarction and stroke at baseline (2006–2007). Cox proportional hazards models were used to estimate stroke risk.

Results—

During the 4-year follow-up, we identified 1486 incident stroke events (1057 ischemic, 386 intracerebral hemorrhagic, and 43 subarachnoid hemorrhagic). The hazard ratios (95% confidence interval) for total stroke with adherence to 0 (reference), 1, 2, 3, 4, 5, and 6/7 ideal CVH metrics were: 1, 0.92 (0.69–1.23), 0.69 (0.52–0.92), 0.52 (0.39–0.68), 0.38 (0.28–0.51), 0.27 (0.18–0.40), and 0.24 (0.11–0.54), respectively (
P
trend <0.01), after adjusting for age, sex, education, income, and hospital. Similar inverse associations were observed for both ischemic and intracerebral hemorrhagic stroke (both
P
trend <0.01).

Conclusions—

We observed a clear inverse gradient relationship between the number of ideal CVH metrics and the risk of stroke in a Chinese population, supporting the importance of ideal health behaviors and factors in stroke prevention.
Corporate Personality from an Islamic Perspective
Authors: Zahid Anowar
Published: July 2013

Abstract

Corporate personality is said to be a Western concept, but is it also Islamic? Answering this question is a demand of the day in view of the ever-increasing number of Islamic commercial and financial entities. For example, the legal personality of the first Islamic Bank of Malaysia, Bank Islam Malaysia Berhad, has been brought to question following an unreported case, Bank Islam Malaysia Bhd. v. Adnan Bin Omar (1994). In an attempt to answer this question, this article overviews the arguments of Islamic jurists on this issue and puts forward its own judgment.
Shariʿah Governance System in Islamic Financial Institutions: New Issues and Challenges
Authors: Grassa Rihab
Published: July 2013

Abstract

Shariʿah governance is considered an unique characteristic of governance in financial architecture as it is concerned with the religious aspect of the overall behaviour of Islamic financial institutions compared to the conventional model of governance. Shariʿah governance is defined as the internal mechanism which helps to ensure that an Islamic financial institution complies with the Shariʿah in its operations and activities and which helps it to achieve the objectives of maqāṣid al-shariʿah. Today, with the significant and rapid growth of the Islamic financial industry worldwide, a strong Shariʿah governance framework seems to be needed now more than before. Effective Shariʿah governance is crucial to strengthen the credibility of the Islamic financial industry. Failure to provide efficient Shariʿah governance may have serious consequences on the development of the Islamic financial system. This article aims to review the Shariʿah governance system and its practice in Islamic financial institutions internationally and discusses the current issues and challenges facing Shariʿah governance.
Property (Māl) and Credit Relations in Islamic Law: An Explanation of Dayn and the Function of Legal Personality (Dhimma)
Authors: Cattelan Valentino
Published: July 2013

Abstract

This article deals with the notion of property (māl) and the conceptualization of credit relations in Islamic law by investigating the dyad ʿayn/dayn and highlighting the functional linkage between dayn (debt/credit) and dhimma (legal personality). More precisely, in accordance with the elaboration of classical scholars, the work illustrates the notion of dayn, not in terms of obligation but as a property already owned by the creditor, while subsisting over the dhimma of the debtor: i.e., a property-in-the-future guaranteed by this dhimma. Differences from the Western notion of obligation, as well as peculiarities of Islamic contract law, are subsequently outlined.
“Weather Girls” on the Big Screen: Stereotypes, Sex Appeal, and Science
Authors: Perryman Nyssa , Theiss Sandra
Published: July 2013

Women currently in the broadcasting meteorology field have dealt with—and continue to deal with—restrictive stereotypes based on the public's perception of their physical appearance and intelligence, largely stemming from the “weather girl” stereotype developed in the 1950s. This sexist stereotype is best seen and often exaggerated in cinematic films and television shows; however, the public's ability to distinguish the truthful and fictitious aspects of these stereotypes is important because these stereotypes limit the level of trust established between female weathercasters and viewers while consequently impeding the public response to dangerous weather situations.

This study will evaluate the origin of the weather girl stereotype associated with female broadcast meteorologists throughout history and use this information to further understand the representation of women weathercasters in several films and television episodes, in order to determine if the weather girl stereotype is further perpetrated in popular cultural media. The study found that these films and episodes actually serve to diminish the role of female weathercasters by reducing them to nothing more than a weather girl.
Investigation of PR and TMI Version 6 and Version 7 Rainfall Algorithms in Landfalling Tropical Cyclones Relative to the NEXRAD Stage-IV Multisensor Precipitation Estimate Dataset
Authors: Zagrodnik Joseph P. , Jiang Haiyan
Published: July 2013

Rainfall estimates from versions 6 (V6) and 7 (V7) of the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) 2A25 and Microwave Imager (TMI) 2A12 algorithms are compared relative to the Next Generation Weather Radar (NEXRAD) Multisensor Precipitation Estimate stage-IV hourly rainfall product. The dataset consists of 252 TRMM overpasses of tropical cyclones from 2002 to 2010 within a 230-km range of southeastern U.S. Weather Surveillance Radar-1988 Doppler (WSR-88D) sites. All rainfall estimates are averaged to a uniform 1/7° square grid. The grid boxes are also divided by their TMI surface designation (land, ocean, or coast). A detailed statistical analysis is undertaken to determine how changes to the TRMM rainfall algorithms in the latest version (V7) are influencing the rainfall retrievals relative to ground reference data. Version 7 of the PR 2A25 is the best-performing algorithm over all three surface types. Over ocean, TMI 2A12 V7 is improved relative to V6 at high rain rates. At low rain rates, the new ocean TMI V7 probability-of-rain parameter creates ambiguity in differentiating light rain (≤0.5 mm h−1) and nonraining areas. Over land, TMI V7 underestimates stage IV more than V6 does at a wide range of rain rates, resulting in an increased negative bias. Both versions of the TMI coastal algorithm are also negatively biased at both moderate and heavy rain rates. Some of the TMI biases can be explained by uncertain relationships between rain rate and 85-GHz ice scattering.
Retrieval of Cloud Properties Using CALIPSO Imaging Infrared Radiometer. Part II: Effective Diameter and Ice Water Path
Authors: Garnier Anne , Pelon Jacques , Dubuisson Philippe , Yang Ping , Faivre Michaël , Chomette Olivier , Pascal Nicolas , Lucker Pat , Murray Tim
Published: July 2013

This paper describes the version-3 level-2 operational analysis of the Imaging Infrared Radiometer (IIR) data collected in the framework of the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission to retrieve cirrus cloud effective diameter and ice water path in synergy with the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) collocated observations. The analysis uses a multisensor split-window technique relying on the concept of microphysical index applied to the two pairs of channels (12.05, 10.6 μm) and (12.05, 8.65 μm) to retrieve cirrus microphysical properties (effective diameter, ice water path) at 1-km pixel resolution. Retrievals are performed for three crystal families selected from precomputed lookup tables identified as representative of the main relationships between the microphysical indices. The uncertainties in the microphysical indices are detailed and quantified, and the impact on the retrievals is simulated. The possible biases have been assessed through consistency checks that are based on effective emissivity difference. It has been shown that particle effective diameters of single-layered cirrus clouds can be retrieved, for the first time, down to effective emissivities close to 0.05 when accurate measured background radiances can be used and up to 0.95 over ocean and land, as well as over low opaque clouds. The retrieval of the ice water path from the IIR effective optical depth and the effective diameter is discussed. Taking advantage of the cloud boundaries retrieved by CALIOP, an IIR power-law relationship between ice water content and extinction is established for four temperature ranges and shown to be consistent with previous results on average for the chosen dataset.
The Upslope–Downslope Flow Transition on a Basin Sidewall
Authors: Villagrasa Daniel Martínez , Lehner Manuela , Whiteman C. David , Hoch Sebastian W. , Cuxart Joan
Published: July 2013

The late afternoon upslope–downslope flow transition on the west inner sidewall of Arizona’s Meteor Crater, visualized by photographs of smoke dispersion, is investigated for 20 October 2006 using surface radiative and energy budget data and mean and turbulent flow profiles from three towers, two at different distances up the slope and one on the basin floor. The bowl-shaped crater allows the development of the upslope–downslope flow transition with minimal influence from larger-scale motions from outside and avoiding the upvalley–downvalley flow interactions typical of valleys. The slow downslope propagation of the shadow from the west rim causes a change in the surface radiation budget and the consequent loss of heat from the shallow atmospheric layer above the western slope at a time when the sun still heats the crater floor and the inner east sidewall. The onset of the katabatic flow is visualized by the dispersion of the smoke, and the onset occurs at the same time at the two slope towers. The katabatic flow arrives later at the crater floor, cooling the air and contributing to the stabilization of a shallow but strong inversion layer there. A wavelet analysis indicates that the initial upslope current is driven by crater-size scales, whereas the later downslope flow is influenced by the thermal gradient between opposing sidewalls generated by their different cooling rates. A comparison with other days suggests that the timing of the transition is also influenced by the presence of convective eddies in addition to the local energy balance.
Interannual Variability of the East Asian Winter Monsoon and Related Modulations of the Planetary Waves
Authors: Takaya Koutarou , Nakamura Hisashi
Published: July 2013

Interannual variability of the East Asian winter monsoon is investigated through composite analysis applied to observational data for 50 recent years. Although the monsoon activity itself is confined into the lower troposphere, its midwinter variability tends to accompany upper-tropospheric geopotential height anomalies similar to the Eurasian (EU) and western Pacific (WP) teleconnection patterns. The “EU-like” pattern is characterized by a wavy signature over the Eurasian continent and the North Atlantic, with surface temperature anomalies over the Far East and North America. In the “WP-like” pattern, a meridional dipole of upper-level height anomalies is evident over the Far East.

These anomaly patterns related to the anomalous winter monsoon activity are found to accompany marked modulations of the climatological development of the upper-tropospheric planetary waves from late autumn to midwinter. Enhanced monsoon activity in January associated with the WP-like pattern involves anomalous seasonal development of a planetary wave ridge with enhanced positive height tendencies from November to January over eastern Siberia and Alaska, while the corresponding tendencies are anomalously negative under the weakened monsoon activity. The stronger monsoon also accompanies an enhanced seasonal decline of geopotential height over the midlatitude North Pacific, corresponding to the enhanced southeastward development of a planetary wave trough. Similar modulations of the planetary wave evolution are observed with the anomalous monsoon activity associated with the EU-like pattern. In addition, the anomalous midwinter activity of the monsoon is also accompanied by noticeable variability of the seasonal development of the planetary waves over the Euro-Atlantic sector.
Multiscale Performance of the ALARO-0 Model for Simulating Extreme Summer Precipitation Climatology in Belgium
Authors: De Troch Rozemien , Hamdi Rafiq , Van de Vyver Hans , Geleyn Jean-François , Termonia Piet
Published: July 2013

Daily summer precipitation over Belgium from the Aire Limitée Adaptation Dynamique Développement International (ALADIN) model and a version of the model that has been updated with physical parameterizations, the so-called ALARO-0 model [ALADIN and AROME (Application de la Recherche à l'Opérationnel à Meso-Echelle) combined model, first baseline version released in 1998], are compared with respect to station observations for the period 1961–90. The 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) is dynamically downscaled using both models on a horizontal resolution of 40 km, followed by a one-way nesting on high spatial resolutions of 10 and 4 km. This setup allows us to explore the relative importance of spatial resolution versus parameterization formulation on the model skill to correctly simulate extreme daily precipitation. Model performances are assessed through standard statistical errors and density, frequency, and quantile distributions as well as extreme value analysis, using the peak-over-threshold method and generalized Pareto distribution. The 40-km simulations of ALADIN and ALARO-0 show similar results, both reproducing the observations reasonably well. For the high-resolution simulations, ALARO-0 at both 10 and 4 km is in better agreement with the observations than ALADIN. The ALADIN model consistently produces too high precipitation rates. The findings demonstrate that the new parameterizations within the ALARO-0 model are responsible for a correct simulation of extreme summer precipitation at various horizontal resolutions. Moreover, this study shows that ALARO-0 is a good candidate model for regional climate modeling.
Probability of Tornado Occurrence across Canada
Authors: Cheng Vincent Y. S. , Arhonditsis George B. , Sills David M. L. , Auld Heather , Shephard Mark W. , Gough William A. , Klaassen Joan
Published: July 2013

The number of tornado observations in Canada is believed to be significantly lower than the actual occurrences. To account for this bias, the authors propose a Bayesian modeling approach founded upon the explicit consideration of the population sampling bias in tornado observations and the predictive relationship between cloud-to-ground (CG) lightning flash climatology and tornado occurrence. The latter variable was used as an indicator for quantifying convective storm activity, which is generally a precursor to tornado occurrence. The CG lightning data were generated from an 11-yr lightning climatology survey (1999–2009) from the Canadian Lightning Detection Network. The results suggest that the predictions of tornado occurrence in populated areas are fairly reliable with no profound underestimation bias. In sparsely populated areas, the analysis shows that the probability of tornado occurrence is significantly higher than what is represented in the 30-yr data record. Areas with low population density but high lightning flash density demonstrate the greatest discrepancy between predicted and observed tornado occurrence. A sensitivity analysis with various grid sizes was also conducted. It was found that the predictive statements supported by the model are fairly robust to the grid configuration, but the population density per grid cell is more representative to the actual population density at smaller resolution and therefore more accurately depicts the probability of tornado occurrence. Finally, a tornado probability map is calculated for Canada based on the frequency of tornado occurrence derived from the model and the estimated damage area of individual tornado events.
Global Hydrological Cycle Response to Rapid and Slow Global Warming
Authors: Back Larissa , Russ Karen , Liu Zhengyu , Inoue Kuniaki , Zhang Jiaxu , Otto-Bliesner Bette
Published: July 2013

This study analyzes the response of global water vapor to global warming in a series of fully coupled climate model simulations. The authors find that a roughly 7% K−1 rate of increase of water vapor with global surface temperature is robust only for rapid anthropogenic-like climate change. For slower warming that occurred naturally in the past, the Southern Ocean has time to equilibrate, producing a different pattern of surface warming, so that water vapor increases at only 4.2% K−1. This lower rate of increase of water vapor with warming is not due to relative humidity changes or differences in mean lower-tropospheric temperature. A temperature of over 80°C would be required in the Clausius–Clapeyron relationship to match the 4.2% K−1 rate of increase. Instead, the low rate of increase is due to spatially heterogeneous warming. During slower global warming, there is enhanced warming at southern high latitudes, and hence less warming in the tropics per kelvin of global surface temperature increase. This leads to a smaller global water vapor increase, because most of the atmospheric water vapor is in the tropics. A formula is proposed that applies to general warming scenarios. This study also examines the response of global-mean precipitation and the meridional profile of precipitation minus evaporation and compares the latter to thermodynamic scalings. It is found that global-mean precipitation changes are remarkably robust between rapid and slow warming. Thermodynamic scalings for the rapid- and slow-warming zonal-mean precipitation are similar, but the precipitation changes are significantly different, suggesting that circulation changes are important in driving these differences.