bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing a Message for Public Education Regarding Stroke
Authors: Kleindorfer Dawn O. , Miller Rosie , Moomaw Charles J. , Alwell Kathleen , Broderick Joseph P. , Khoury Jane , Woo Daniel , Flaherty Matthew L. , Zakaria Tarek , Kissela Brett M.
Published: August 2007

Background and Purpose—

Previous studies have shown poor public knowledge of stroke warning signs. The current public education message adopted by the American Heart Association lists 5 stroke warning signs (“suddens”). Another message called FAST (face, arm, speech, time) could be easier to remember, but it does not contain as many stroke symptoms. We sought to assess the percentage of stroke/transient ischemic attack (TIA) patients identified by both public awareness messages by examining presenting symptoms of all stroke/TIA patients from a large, biracial population in 1999.

Methods—

Cases of stroke who presented to an emergency department or were directly admitted were ascertained at all local hospitals by screening of ICD-9 codes 430 to 436, and prospective screening of emergency department admission logs, in 1999. Study nurses abstracted initial presenting symptoms from the medical record. All-cause 30-day case-fatality was calculated.

Results—

During 1999, 3498 stroke/TIA patients (17% black, 56% female) presented to an emergency department. Of these events, 11.1% had presenting symptoms not included in FAST, whereas 0.1% had presenting symptoms not included in the suddens. The FAST message performed much better for ischemic stroke and TIA than for hemorrhage, missing 8.9% of the ischemic strokes and 8.2% of the TIAs, versus 30.6% of intracerebral hemorrhage/subarachnoid hemorrhage cases. Case-fatality in patients missed by FAST was similar to patients with FAST symptoms (9.0% versus 11.6%,
P
=0.15).

Conclusions—

Within our population, we found that the FAST message identified 88.9% of stroke/TIA patients. The FAST message performed better for ischemic stroke and TIA than for hemorrhagic stroke. Whether the FAST message is easier to recall for the public than the “suddens” message has yet to be determined.
The Increase of Circulating Endothelial Progenitor Cells After Acute Ischemic Stroke Is Associated With Good Outcome
Authors: Sobrino Tomás , Hurtado Olivia , Moro María Ángeles , Rodríguez-Yáñez Manuel , Castellanos Mar , Brea David , Moldes Octavio , Blanco Miguel , Arenillas Juan F. , Leira Rogelio , Dávalos Antonio , Lizasoain Ignacio , Castillo José
Published: August 2007

Background and Purpose—

Increased circulating endothelial progenitor cells (EPC) have been associated with a low cardiovascular risk and may be involved in endothelial cell regeneration. The present study was designed to evaluate the prognostic value of EPC in acute ischemic stroke.

Methods—

Forty-eight patients with a first-ever nonlacunar ischemic stroke were prospectively included in the study within 12 hours of symptoms onset. Stroke severity was evaluated by the National Institutes of Health Stroke Scale, and functional outcome was assessed at 3 months by the modified Rankin Scale (mRS). Infarct volume growth between admission and days 4 to 7 was measured on multiparametric MRI. EPC colonies were defined as early outgrowth colony-forming unit-endothelial cell (CFU-EC). The increment of CFU-EC was quantified during the first week and defined as the absolute difference between the number of CFU-EC at day 7 and admission. The influence of CFU-EC increase on good functional outcome (mRS ≤2) and infarct growth was analyzed by logistic regression and linear models.

Results—

Patients with good outcome (n=25) showed a higher CFU-EC increment during the first week (median [quartiles], 23 [11, 36] versus −3 [−7, 1],
P
<0.0001) compared with patients with poor outcome. CFU-EC increment ≥4 during the first week was associated with good functional outcome at 3 months (odds ratio, 30.7; 95% CI, 2.4 to 375.7;
P
=0.004) after adjustment for baseline stroke severity, ischemic volume and thrombolytic treatment. For each unit increase in the CFU-EC the mean reduction in the growth of infarct volume was 0.39 (0.03 to 0.76) mL (
P
=0.033).

Conclusions—

The increase of circulating EPC after acute ischemic stroke is associated with good functional outcome and reduced infarct growth. These findings suggest that EPC might participate in neurorepair after ischemic stroke.
Echocardiographic Left Ventricular Mass Index Predicts Incident Stroke in African Americans
Authors: Fox Ervin R. , Alnabhan Nabhan , Penman Alan D. , Butler Kenneth R. , Taylor Herman A. , Skelton Thomas N. , Mosley Thomas H.
Published: August 2007

Background and Purpose—

Despite theories that link stroke to left ventricular mass, few large, population-based studies have examined the predictive value of echocardiographically derived left ventricular mass index (LVMI) to incident stroke in African Americans.

Methods—

Participants in the Jackson cohort of the Atherosclerotic Risk in Communities study have had extensive baseline evaluations, have undergone echocardiography during the third examination (1993–1995), and have been followed up for incident cardiovascular disease including ischemic stroke.

Results—

The study population consisted of 1792 participants, of whom 639 (35.7%) were men and the mean±SD age was 58.8±5.7 years. Compared with those without ischemic stroke, those with ischemic stroke had a higher frequency of hypertension (85.6% vs 58.7%) and diabetes (46.9% vs 21.0%). Left ventricular hypertrophy was more prevalent in those with stroke (62.2% vs 38.6%). During a median follow-up of 8.8 years, 98 incident strokes occurred (6.5 per 1000 person-years). LVMI was independently associated with stroke after adjusting for age, sex, hypertension, systolic blood pressure, smoking, diabetes, total to HDL cholesterol ratio, body mass index, and low left ventricular ejection fraction (adjusted hazard ratio per 10 g/m
2.7
increment of LVMI=1.15; 95% CI, 1.02 to 1.28). The relation remained statistically significant after adding left atrial size and mitral annular calcification to the multivariable model.

Conclusions—

In this large, population-based African American cohort, we found that echocardiographic LVMI was an independent predictor of incident ischemic stroke even after taking into account traditional clinical risk factors.
Stimulating Circle of Willis Nerve Fibers Preserves the Diffusion-Perfusion Mismatch in Experimental Stroke
Authors: Henninger Nils , Fisher Marc
Published: August 2007

Background and Purpose—

Stimulation of the nerves traversing the ethmoidal foramen (including postsynaptic, parasympathetic projections from the sphenopalatine ganglion [SPG], henceforth referred to as “SPG-stimulation”) has been shown to elevate cerebral blood flow (CBF) and to be neuroprotective after permanent, middle cerebral artery occlusion (pMCAO).

Methods—

Employing diffusion (DWI)- and perfusion (PWI) weighted MRI, the effect of SPG-stimulation (started at 60 minutes post-MCAO) on the spatiotemporal evolution of ischemia during and after pMCAO was investigated. In an additional experiment, regional CBF changes were investigated in the nonischemic brain.

Results—

In the nonischemic brain, SPG stimulation significantly elevated CBF predominantly within areas supplied by the anterior cerebral artery (by 0.64 mL/g/min relative to baseline). In the ischemic brain, CBF only marginally increased within the penumbra and core (by up to 0.08 and 0.15 mL/g/min relative to prestimulation, respectively). However, the threshold-derived CBF lesion volume did not change significantly. Penumbral apparent diffusion coefficient (ADC)-values improved to almost baseline values and the threshold derived ADC/CBF-mismatch was preserved up to 180 minutes after MCAO. TTC-derived lesion volumes were significantly smaller in stimulated versus nonstimulated animals (120.4±74.1 mm
3
versus 239.3±68.5 mm
3
, respectively).

Conclusion—

This study demonstrates that unilateral SPG-stimulation increases CBF bilaterally within the normal brain, acutely preserves the CBF/ADC mismatch largely independent of altering cerebral blood flow, and reduces infarct size in the rat permanent suture model.
Continuous Time-Domain Analysis of Cerebrovascular Autoregulation Using Near-Infrared Spectroscopy
Authors: Brady Ken M. , Lee Jennifer K. , Kibler Kathleen K. , Smielewski Piotr , Czosnyka Marek , Easley R. Blaine , Koehler Raymond C. , Shaffner Donald H.
Published: August 2007

Background and Purpose—

Assessment of autoregulation in the time domain is a promising monitoring method for actively optimizating cerebral perfusion pressure (CPP) in critically ill patients. The ability to detect loss of autoregulatory vasoreactivity to spontaneous fluctuations in CPP was tested with a new time-domain method that used near-infrared spectroscopic measurements of tissue oxyhemoglobin saturation in an infant animal model.

Methods—

Piglets were made progressively hypotensive over 4 to 5 hours by inflation of a balloon catheter in the inferior vena cava, and the breakpoint of autoregulation was determined using laser-Doppler flowmetry. The cerebral oximetry index (COx) was determined as a moving linear correlation coefficient between CPP and INVOS cerebral oximeter waveforms during 300-second periods. A laser-Doppler derived time-domain analysis of spontaneous autoregulation with the same parameters (LDx) was also determined.

Results—

An increase in the correlation coefficient between cerebral oximetry values and dynamic CPP fluctuations, indicative of a pressure-passive relationship, occurred when CPP was below the steady state autoregulatory breakpoint. This COx had 92% sensitivity (73% to 99%) and 63% specificity (48% to 76%) for detecting loss of autoregulation attributable to hypotension when COx was above a threshold of 0.36. The area under the receiver-operator characteristics curve for the COx was 0.89. COx correlated with LDx when values were sorted and averaged according to the CPP at which they were obtained (
r
=0.67).

Conclusions—

The COx is sensitive for loss of autoregulation attributable to hypotension and is a promising monitoring tool for determining optimal CPP for patients with acute brain injury.
Association of Kallikrein Gene Polymorphisms With Intracranial Aneurysms
Authors: Weinsheimer Shantel , Goddard Katrina A.B. , Parrado Antonio R. , Lu Qing , Sinha Moumita , Lebedeva Elena R. , Ronkainen Antti , Niemelä Mika , Khusnutdinova Elza K. , Khusainova Rita I. , Helin Katariina , Jääskeläinen Juha E. , Sakovich Vladimir P. , Land Susan , Kuivaniemi Helena , Tromp Gerard
Published: August 2007

Background and Purpose—

Genomewide DNA linkage analysis identified a susceptibility locus for intracranial aneurysm (IA) on chromosome 19q13 in the Finnish population, a region including the kallikrein gene cluster. We investigated the association of single nucleotide polymorphisms (SNPs) in the kallikrein gene cluster with IA in the Finnish population.

Methods—

We genotyped 18 haplotype-tagging SNPs spanning a 244 kbp region in the kallikrein gene cluster for 266 Finnish IA cases and 290 Finnish control subjects. In a second phase, we genotyped 2 SNPs (rs1722561 and rs1701946) in an additional set of 102 Finnish IA cases and 102 Finnish control subjects; and in a third phase, we genotyped these 2 SNPs in 156 Russian IA cases and 186 Russian control subjects. Both single-marker and haplotype-based tests of association were performed.

Results—

In phase I, SNPs rs1722561 and rs1701946 were significantly associated with IA in the Finnish population for single locus models (rs1722561:
P
=0.0395; rs1701946:
P
=0.0253). A 2-SNP haplotype block (rs1722561–rs1701946) identified in phase I was also associated with IA in the expanded Finnish (phase II) data set (asymptotic
P
=0.012; empirical
P
=0.019). In the Finnish and Russian combined data set (phase III) with 524 cases and 578 control subjects, the same 2 SNPs (OR: 1.35, 95% CI: 1.14, 1.60;
P
=0.0005 for rs1722561 and OR: 1.32, 95% CI: 1.12, 1.57;
P
=0.0011 for rs1701946) were significantly associated with IA. These SNPs are located in the intronic region of
KLK8
, although linkage disequilibrium could extend from rs268912–rs2250066, a ≈76-kbp region that includes KLK5–KLK10.

Conclusions—

Polymorphisms within the kallikrein gene cluster are associated with IA suggesting that the kallikreins are important candidate genes for IA.
Artery-Related Differences in Atherosclerosis Expression
Authors: Dalager Søren , Paaske William P. , Bayer Kristensen Ingrid , Marsvin Laurberg Jacob , Falk Erling
Published: August 2007

Background and Purpose—

Information about the expression of atherosclerosis in different arteries is important. The impact of cardiovascular risk factors is artery-related, and the assessment of arterial structure and function in peripheral arteries are increasingly used as surrogate markers for coronary atherosclerosis and the risk of developing heart attack.

Methods—

In an autopsy study, we analyzed the coronary, carotid and superficial femoral arteries from 100 individuals (70 men; 20 to 82 years of age) of which 27 died from coronary atherosclerosis. Microscopic sections (n=4756) were analyzed blindly using a modification of the histological classification endorsed by the American Heart Association (AHA).

Results—

We found distinct artery-dependent patterns of atherosclerosis with a high prevalence of foam cell lesions and lipid core plaques in the carotid arteries. The femoral arteries were least affected by atherosclerosis, foam cell lesions were rare, and the development of advanced atherosclerosis was strongly age-dependent and dominated by fibrous plaques. Plaques were most common in the left anterior descending coronary artery and the carotid bifurcation. In coronary (versus noncoronary) death, lipid core plaques were more prevalent in all arteries.

Conclusions—

The initiation, speed of development, and phenotypic expression of atherosclerotic plaques are artery-related. Foam cell lesions are frequent in the carotid arteries, probably explaining the dynamics in carotid intima-media thickness. Atherosclerosis develops slowly in femoral arteries, and severe atherosclerosis is dominated by fibrous plaques. The higher prevalence of lipid core plaques in all arteries in coronary death indicates a systemically more vulnerable expression of atherosclerosis in these individuals.
Lipopolysaccharide Induces Early Tolerance to Excitotoxicity via Nitric Oxide and cGMP
Authors: Orio Marcello , Kunz Alexander , Kawano Takayuki , Anrather Josef , Zhou Ping , Iadecola Costantino
Published: August 2007

Background and Purpose—

Sublethal injury induces tolerance to a subsequent lethal insult, a phenomenon termed preconditioning (PC). PC occurs within hours (early tolerance) or days (delayed tolerance) after the inducing stimulus. In the brain, delayed tolerance has been studied extensively, but very little is known about early tolerance. We investigated whether the proinflammatory agent lipopolysaccharide (LPS), a well-established inducer of delayed tolerance, can also induce early tolerance and, if so, whether nitric oxide (NO) is involved in its mechanisms.

Methods—

In C57BL/6 mice, LPS was administered and
N
-methyl-
d
-aspartate (NMDA) was microinjected into the neocortex 30 minutes to 24 hours later. Lesion volume was assessed 24 hours after NMDA administration in thionine-stained sections.

Results—

LPS reduced NMDA lesions when administered 1 hour (−25±1%;
P
<0.05, n=5 per group) or 24 hours (−25±4%;
P
<0.05, n=5 per group) before NMDA application. LPS administration 30 minutes or 2 to 4 hours before NMDA administration was not neuroprotective (
P
>0.05). The protection at 1 hour was independent of protein synthesis and was blocked by inhibition of neuronal NO synthase or soluble guanylyl cyclase. Furthermore, early protection was not observed in neuronal or endothelial NO synthase–null mice, but it was present in inducible NO synthase–null mice.

Conclusions—

The data demonstrate that LPS induces both early and late tolerance. At variance with delayed tolerance, which depends on inducible NO synthase and peroxynitrite, early tolerance is mediated by endothelial and neuronal NO through production of cGMP. The findings suggest that LPS can trigger signaling between endothelial cells and neurons, leading to NO production and cGMP-dependent neuroprotection.
Risk Factors for Intracerebral Hemorrhage in a Pooled Prospective Study
Authors: Sturgeon Jared D. , Folsom Aaron R. , Longstreth W.T. , Shahar Eyal , Rosamond Wayne D. , Cushman Mary
Published: August 2007

Background and Purpose—

Few prospective studies have reported risk factors for intracerebral hemorrhage (ICH), and results are inconsistent. We studied risk factors for ICH in a pooled cohort of the Atherosclerosis Risk in Communities Study (ARIC) and the Cardiovascular Health Study (CHS).

Methods—

The ARIC cohort was recruited in 1987 to 1989 and involves 15 792 men and women, aged 45 to 64 years at baseline, sampled from 4 US communities. The CHS cohort was recruited in 1989 to 1993 and involves 5888 men and women, aged 65 or over at baseline, sampled from 4 US communities. Baseline measurements included many potential vascular risk factors. The cohorts were followed for incident stroke events.

Results—

Over 263 489 person-years of follow-up, 135 incident ICH events occurred. In a multivariable model, age, African-American ethnicity (versus Whites), and hypertension were positively associated with incident ICH, whereas low-density lipoprotein cholesterol and triglycerides were inversely related to incident ICH. Participants with systolic blood pressure
≥
160 mm Hg or diastolic blood pressure
≥
110 mm Hg had 5.55 (95% CI 3.07 to 10.0) times the rate of ICH as nonhypertensives. Sex, smoking, alcohol intake, body mass index, waist-to-hip ratio, waist circumference, and diabetes were not related to ICH.

Conclusions—

In this pooled cohort the risk factors for ICH were older age, African-American ethnicity, hypertension, lower LDL-C, and lower triglycerides.
Magnetic Resonance Spectroscopy Study of Oxygen Therapy in Ischemic Stroke
Authors: Singhal Aneesh B. , Ratai Eva , Benner Thomas , Vangel Mark , Lee Vallent , Koroshetz Walter J. , Schaefer Pamela W. , Sorensen A. Gregory , Gonzalez R. Gilberto
Published: August 2007

Background and Purpose—

Recent studies suggest that normobaric oxygen therapy (NBO) is neuroprotective in acute ischemic stroke.

Methods—

We performed multivoxel magnetic resonance spectroscopic imaging and diffusion/perfusion MRI in patients with stroke treated with NBO or room air. Imaging was performed before, during, and after therapy.

Results—

Voxel-based analysis showed excellent correlation between apparent diffusion coefficient values, lactate, and
N
-acetyl-aspartate levels at all time points. Lactate decreased during NBO and increased post-NBO.
N
-acetyl-aspartate decreased in patients receiving room air but not in NBO-treated patients.

Conclusion—

These data suggest that NBO improves aerobic metabolism and preserves neuronal integrity in the ischemic brain.
Detection of Carotid Adventitial Vasa Vasorum and Plaque Vascularization With Ultrasound Cadence Contrast Pulse Sequencing Technique and Echo-Contrast Agent
Authors: Vicenzini Edoardo , Giannoni Maria Fabrizia , Puccinelli Francesco , Ricciardi Maria Chiara , Altieri Marta , Di Piero Vittorio , Gossetti Bruno , Benedetti Valentini Fabrizio , Lenzi Gian Luigi
Published: August 2007

Background and Purpose—

Adventitial vasa vasorum and plaque vascularization have been established as predictors of unstable atheromasic lesions in cerebro- and cardiovascular patients. Ultrasound contrast agents provide reliable information on tissue perfusion and microcirculation. We used contrast ultrasound duplex scanning to identify carotid plaque vascularization.

Methods—

Contrast carotid duplex scanning was performed in 23 patients with plaques of different degree of stenosis and echogenicity.

Results—

Plaque vascularization was detected in the fibrous and fibro-fatty tissue and not observed in the calcific nor in the necrotic and hemorrhagic tissue. Constantly, a small vessel was observed under ulcerations.

Conclusions—

Carotid contrast ultrasound imaging appears to be an emerging technique for identifying plaque angiogenesis. Further studies are needed to clarify the role of plaque angiogenesis for assessing cerebrovascular risk and to monitor effects of therapies aimed to plaque remodelling.
Selective Impairment of Working Memory in a Mouse Model of Chronic Cerebral Hypoperfusion
Authors: Shibata Masunari , Yamasaki Nobuyuki , Miyakawa Tsuyoshi , Kalaria Rajesh N. , Fujita Youshi , Ohtani Ryo , Ihara Masafumi , Takahashi Ryosuke , Tomimoto Hidekazu
Published: August 2007

Background and Purpose—

We recently designed a mouse model of chronic cerebral hypoperfusion, in which the cerebral white matter is damaged without significant gray matter lesions. The behavioral characteristics of these mice were studied using a test battery for neurological and cognitive functions.

Methods—

Adult C57Bl/6 male mice were subjected to either sham-operation or bilateral common carotid artery stenosis (BCAS) using microcoils with an internal diameter of 0.18 mm. At 30 days after BCAS, 70 animals were divided into 3 groups and subjected to behavioral test batteries. The first group underwent comprehensive behavioral test, including the neurological screen, prepulse inhibition, hot plate, open field, light/dark transition, Porsolt forced swim and contextual and cued fear conditioning (BCAS n=13; sham-operated n=11). The second group was for the working memory task of the 8-arm radial maze test (BCAS n=12; sham-operated n=10), and the third for the reference memory task of the 8-arm radial maze test (BCAS n=13; sham-operated n=11). Another batch of animals were examined for histological changes (BCAS n=11; sham-operated n=12).

Results—

The white matter including the corpus callosum was consistently found to be rarefied without clear ischemic lesions in the hippocampus. No apparent differences were observed in the comprehensive test batteries between the control and BCAS mice. However, in the working memory tasks tested with the 8-arm radial maze, the BCAS mice made significantly more errors than the control mice (
P
<0.0001). Again, there were no detectable differences in the reference memory tasks between the groups.

Conclusions—

At 30 days after BCAS, working memory deficits as well as white matter changes were apparent in the mice. Working memory deficit was attributable to damage of the frontal-subcortical circuits, suggesting the BCAS model is useful to evaluate the substrates of subcortical vascular dementia.
Higher Total Serum Cholesterol Levels Are Associated With Less Severe Strokes and Lower All-Cause Mortality
Authors: Olsen Tom Skyhøj , Christensen Rune Haubo Bojesen , Kammersgaard Lars Peter , Andersen Klaus Kaae
Published: August 2007

Background and Purpose—

Evidence of a causal relation between serum cholesterol and stroke is inconsistent. We investigated the relation between total serum cholesterol and both stroke severity and poststroke mortality to test the hypothesis that hypercholesterolemia is primarily associated with minor stroke.

Methods—

In the study, 652 unselected patients with ischemic stroke arrived at the hospital within 24 hours of stroke onset. A measure of total serum cholesterol was obtained in 513 (79%) within the 24-hour time window. Stroke severity was measured with the Scandinavian Stroke Scale (0=worst, 58=best); a full cardiovascular risk profile was established for all. Death within 10 years after stroke onset was obtained from the Danish Registry of Persons.

Results—

Mean±SD age of the 513 patients was 75±10 years, 54% were women, and the mean±SD Scandinavian Stroke Scale score was 39±17. Serum cholesterol was inversely and almost linearly related to stroke severity: an increase of 1 mmol/L in total serum cholesterol resulted in an increase in the Scandinavian Stroke Scale score of 1.32 (95% CI, 0.28 to 2.36,
P
=0.013), meaning that higher cholesterol levels are associated with less severe strokes. A survival analysis revealed an inverse linear relation between serum cholesterol and mortality, meaning that an increase of 1 mmol/L in cholesterol results in a hazard ratio of 0.89 (95% CI, 0.82 to 0.97,
P
=0.01).

Conclusions—

The results of our study support the hypothesis that a higher cholesterol level favors development of minor strokes. Because of selection, therefore, major strokes are more often seen in patients with lower cholesterol levels. Poststroke mortality, therefore, is inversely related to cholesterol.
Analysis of a Reconstructed Oceanic Kelvin Wave Dynamic Height Dataset for the Period 1974–2005
Authors: Roundy Paul E. , Kiladis George N.
Published: August 2007

Intraseasonal oceanic Kelvin waves are the dominant mode of variability in the thermocline of the equatorial Pacific. Dynamic height data from the Tropical Atmosphere Ocean (TAO) Array of buoys moored in the tropical Pacific offer a convenient grid on which to study the waves but can only be effectively applied to study basinwide wave activity since about 1988 because of insufficient data at earlier times. Kelvin wave signals are also present in sea level data from island and coastal sites from the University of Hawaii Sea Level Center, some of which are available from before 1970 and up to 2003. This work describes a technique for reconstructing equatorial dynamic height data back to 1974, by utilizing regression relationships between the TAO data and daily sea level time series from 11 stations in the tropical Pacific. The reconstructed data are analyzed for skill in approximating Kelvin wave signals when TAO data are available. Reconstructed Kelvin wave signals prior to the TAO period are then analyzed for consistency with the wind stress anomalies that are responsible for generating the waves.

A regression analysis showing intraseasonal patterns of convection and winds that occur during periods of adjustment toward El Niño conditions is applied during the period 1974–87 for comparison with an earlier result calculated from TAO data for 1988–2005. Systematic changes in Kelvin wave phase speed with respect to ENSO documented for the latter period are confirmed in the earlier reconstructed dataset.
Evaluation of Cirrus Parameterizations for Radiative Flux Computations in Climate Models Using TOVS–ScaRaB Satellite Observations
Authors: Stubenrauch C. J. , Eddounia F. , Edwards J. M. , Macke A.
Published: August 2007

Combined simultaneous satellite observations are used to evaluate the performance of parameterizations of the microphysical and optical properties of cirrus clouds used for radiative flux computations in climate models. Atmospheric and cirrus properties retrieved from Television and Infrared Observation Satellite (TIROS-N) Operational Vertical Sounder (TOVS) observations are given as input to the radiative transfer model developed for the Met Office climate model to simulate radiative fluxes at the top of the atmosphere (TOA). Simulated cirrus shortwave (SW) albedos are then compared to those retrieved from collocated Scanner for Radiation Budget (ScaRaB) observations. For the retrieval, special care has been given to angular direction models. Three parameterizations of cirrus ice crystal optical properties are represented in the Met Office radiative transfer model. These parameterizations are based on different physical approximations and different hypotheses on crystal habit. One parameterization assumes pristine ice crystals and two ice crystal aggregates. By relating the cirrus ice water path (IWP) retrieved from the effective infrared emissivity to the cirrus SW albedo, differences between the parameterizations are amplified. This study shows that pristine crystals seem to be plausible only for cirrus with IWP less than 30 g m−2. For larger IWP, ice crystal aggregates lead to cirrus SW albedos in better agreement with the observations. The data also indicate that climate models should allow the cirrus effective ice crystal diameter (De) to increase with IWP, especially in the range up to 30 g m−2. For cirrus with IWP less than 20 g m−2, this would lead to SW albedos that are about 0.02 higher than the ones of a constant De of 55 μm.
Comparison of the Stability of the Atlantic Thermohaline Circulation in Two Coupled Atmosphere–Ocean General Circulation Models
Authors: Yin Jianjun , Stouffer Ronald J.
Published: August 2007

Two coupled atmosphere–ocean general circulation models developed at GFDL show differing stability properties of the Atlantic thermohaline circulation (THC) in the Coupled Model Intercomparison Project/Paleoclimate Modeling Intercomparison Project (CMIP/PMIP) coordinated “water-hosing” experiment. In contrast to the R30 model in which the “off” state of the THC is stable, it is unstable in the CM2.1. This discrepancy has also been found among other climate models. Here a comprehensive analysis is performed to investigate the causes for the differing behaviors of the THC. In agreement with previous work, it is found that the different stability of the THC is closely related to the simulation of a reversed thermohaline circulation (RTHC) and the atmospheric feedback. After the shutdown of the THC, the RTHC is well developed and stable in R30. It transports freshwater into the subtropical North Atlantic, preventing the recovery of the salinity and stabilizing the off mode of the THC. The flux adjustment is a large term in the water budget of the Atlantic Ocean. In contrast, the RTHC is weak and unstable in CM2.1. The atmospheric feedback associated with the southward shift of the Atlantic ITCZ is much more significant. The oceanic freshwater convergence into the subtropical North Atlantic cannot completely compensate for the evaporation, leading to the recovery of the THC in CM2.1. The rapid salinity recovery in the subtropical North Atlantic excites large-scale baroclinic eddies, which propagate northward into the Nordic seas and Irminger Sea. As the large-scale eddies reach the high latitudes of the North Atlantic, the oceanic deep convection restarts. The differences in the southward propagation of the salinity and temperature anomalies from the hosing perturbation region in R30 and CM2.1, and associated different development of a reversed meridional density gradient in the upper South Atlantic, are the cause of the differences in the behavior of the RTHC. The present study sheds light on important physical and dynamical processes in simulating the dynamical behavior of the THC.
An Assessment of the Southern Ocean Mixed Layer Heat Budget
Authors: Dong Shenfu , Gille Sarah T. , Sprintall Janet
Published: August 2007

The mixed layer heat balance in the Southern Ocean is examined by combining remotely sensed measurements and in situ observations from 1 June 2002 to 31 May 2006, coinciding with the period during which Advanced Microwave Scanning Radiometer-Earth Observing System (EOS) (AMSR-E) sea surface temperature measurements are available. Temperature/salinity profiles from Argo floats are used to derive the mixed layer depth. All terms in the heat budget are estimated directly from available data. The domain-averaged terms of oceanic heat advection, entrainment, diffusion, and air–sea flux are largely consistent with the evolution of the mixed layer temperature. The mixed layer temperature undergoes a strong seasonal cycle, which is largely attributed to the air–sea heat fluxes. Entrainment plays a secondary role. Oceanic advection also experiences a seasonal cycle, although it is relatively weak. Most of the seasonal variations in the advection term come from the Ekman advection, in contrast with western boundary current regions where geostrophic advection controls the total advection. Substantial imbalances exist in the regional heat budgets, especially near the northern boundary of the Antarctic Circumpolar Current. The biggest contributor to the surface heat budget error is thought to be the air–sea heat fluxes, because only limited Southern Hemisphere data are available for the reanalysis products, and hence these fluxes have large uncertainties. In particular, the lack of in situ measurements during winter is of fundamental concern. Sensitivity tests suggest that a proper representation of the mixed layer depth is important to close the budget. Salinity influences the stratification in the Southern Ocean; temperature alone provides an imperfect estimate of mixed layer depth and, because of this, also an imperfect estimate of the temperature of water entrained into the mixed layer from below.
Evaluation of a Long-Term (1882–2005) Equivalent Temperature Time Series
Authors: Rogers Jeffrey C. , Wang Sheng-Hung , Coleman Jill S. M.
Published: August 2007

A 124 (1882–2005) summer record of total surface energy content consisting of time series of surface equivalent temperature (TE) and its components T (mean air temperature) and Lq/cp (moist enthalpy, denoted Lq) is developed, quality controlled, and analyzed for Columbus, Ohio, where long records of monthly dewpoint temperature are available. The analysis shows that the highest TE occurs during the summer of 1995 when both T and Lq were very high, associated with a severe midwestern heat wave. That year contrasts with the hot summers of 1930–36, when Lq and TE had relatively low or negative anomalies (low humidity) compared to those of T. Following the 1930–36 summers, T and Lq departures are much more typically the same sign in individual summers, and the two parameters develop a statistically significant high positive correlation into the twenty-first century. Mean T and Lq departures from the long-term normal have opposite signs, however, when summers are stratified either by seasonal total rainfall amounts or by the Palmer drought severity soil moisture index. Normalized trends of T, Lq, and TE are downward from 1940 to 1964 with those of TE exceeding T. Since 1965, however, significant positive T trends slightly exceed TE in magnitude and those of dewpoint temperature and Lq are comparatively lower. A highly significant upward trend in minimum temperatures especially dominates the T variability, creating a significant downward trend in the temperature range that dominates recent summer climate variability more than moisture trends. Regional moisture flux variations are largest away from Columbus, over the upper Midwest and western Atlantic Ocean, during its seasonal extremes in total surface energy.
Rituximab Pharmacokinetics in Patients With Rheumatoid Arthritis: B‐Cell Levels Do Not Correlate With Clinical Response
Authors: Breedveld Ferdinand , Agarwal Sunil , Yin Ming , Ren Song , Li Nicole F. , Shaw Tim M. , Davies Brian E.
Published: August 2007

This study characterized the relationship between clinical response, serum rituximab concentrations, and peripheral B‐cell levels in patients with rheumatoid arthritis treated with rituximab. Data were analyzed from a double‐blind, phase IIa trial in which 161 patients with active rheumatoid arthritis despite continuing methotrexate were randomized to methotrexate alone (10–25 mg/wk), rituximab alone (single course: 1000 mg administered intravenously on days 1 and 15), rituximab plus cyclophosphamide (750 mg administered intravenously on days 3 and 17), or rituximab plus methotrexate. Serum samples for pharmacokinetic analysis were collected through 24 weeks, and peripheral circulating CD19+ B‐cell levels were measured through 48 weeks. All treatments were generally well tolerated, with no clinically relevant excess of adverse events leading to withdrawal among patients who received rituximab compared with those who received methotrexate alone. The proportions of patients who achieved an American College of Rheumatology score of 50 at week 24 were 13% (methotrexate alone), 33% (rituximab alone), 41% (rituximab plus cyclophosphamide), and 43% (rituximab plus methotrexate). Peripheral B‐cell depletion occurred by day 15 in all patients treated with rituximab. There was no relationship between B‐cell depletion and clinical response. Recovery of peripheral B cells was variable and showed no relationship with return of disease activity in patients who responded to rituximab. The mean terminal half‐life of rituximab was 19 to 22 days; pharmacokinetic parameters were similar whether rituximab was administered alone or with methotrexate or cyclophosphamide. Because the level of peripherally circulating B cells does not appear to correlate with a maintained clinical response in patients with rheumatoid arthritis, the timing of rituximab retreatment should be based on clinical symptoms rather than peripheral B‐cell levels.
Maternal Depression and Adolescent Behavior Problems
Authors: Aisenberg Eugene , Trickett Penelope K. , Mennen Ferol E. , Saltzman William , Zayas Luis H.
Published: August 2007

This study examines the psychological and behavioral effects of exposure to community violence of 47 Latino mothers and their young adolescent children. Using data gathered from multiple sources, this study tests the associations between lifetime exposure to community violence, maternal depression, and child behavior problems. More than 80% of the youngsters ranging from age 11 to 14 years and 68% of the mothers reported being exposed to at least one act of community violence either as a victim or as a witness. Analyses reveal that maternal depression is a mediator of child behavior problems, reducing the direct effect of community violence exposure by more than 50%. Findings suggest that maternal depression is a factor more important than child's community violence exposure in contributing to young adolescents' behavioral problems.
Predictors of Adult Attitudes Toward Corporal Punishment of Children
Authors: Gagné Marie-Hélène , Tourigny Marc , Joly Jacques , Pouliot-Lapointe Joëlle
Published: August 2007

This study identifies predictors of favorable attitudes toward spanking. Analyses were performed with survey data collected from a representative sample of 1,000 adults from Quebec, Canada. According to this survey, a majority of respondents endorsed spanking, despite their recognition of potential harm associated with corporal punishment (CP) of children. The prediction model of attitudes toward spanking included demographics, experiencing or witnessing various forms of family violence and abuse in childhood, and perceived frequency of physical injuries resulting from CP. Spanking was the most reported childhood experience (66.4%), and most violence and abuse predictors were significantly and positively correlated. Older respondents who were spanked in childhood and who believed that spanking never or seldom results in physical injuries were the most in favor of spanking. On the other hand, respondents who reported more severe physical violence or psychological abuse in childhood were less in favor of spanking. Findings are discussed in terms of prevention of CP and family coercion cycle.
The Relationship Between Childhood Sexual Abuse and Adult Mental Health Among Undergraduates
Authors: Young M. Scott , Harford Kelli-Lee , Kinder Bill , Savell Jodi K.
Published: August 2007

A large body of research has documented the harmful effects of childhood sexual abuse (CSA) on adult mental health among females, but less work has examined this issue among males. This study examined whether gender moderated the relationship between CSA and adult mental health among a mixed-gender sample of 406 undergraduates. A Pearson chi-square test indicated that a significantly greater proportion of females (41.6%) than males (30.7%) reported a history of CSA. ANCOVAs tested whether gender, CSA status, and their interaction were related to adult mental health symptomatology as measured by Brief Symptom Inventory gender-normed t scores. Participants with a history of CSA reported significantly higher levels of global mental health problems, hostility, paranoid ideation, and psychoticism. The gender by CSA status interaction was not significant for any scale, indicating that the harmful effects of CSA on adult mental health did not vary by gender.
The Influence of Length of Marriage and Fidelity Status on Perception of Marital Rape
Authors: Munge Bethany A. , Pomerantz Andrew M. , Pettibone Jonathan C. , Falconer Jameca W.
Published: August 2007

To what extent does the length of the marriage or the wife's faithfulness to the husband influence the perception of responsibility or trauma in marital rape? In the current study, each participant was presented with one of four marital rape vignettes. The vignettes varied only in the length of the marriage (3 years or 15 years) and the fidelity status of the wife (continuously faithful or involved in an ongoing sexual affair with another man). Results indicate that both length of marriage and fidelity status significantly influence perceptions of marital rape. Specifically, participants assigned greater responsibility for the rape to unfaithful wives than to faithful wives. This finding is particularly salient for wives in long-term marriages as compared to wives in short-term marriages. Additionally, participants perceived rapes within long-term marriages as more traumatic than rapes within short-term marriages.
Adult Perspectives on Growing Up Following Uxoricide
Authors: Steeves Richard H. , Parker Barbara
Published: August 2007

The purpose of this article is to provide an overview of the state of the science on uxoricide, including qualitative findings on 47 survivors. Two qualitative interviews were conducted between January 2004 and January 2005 with 47 convenience sample adult survivors of uxoricide. Data were analyzed using hermeneutic analysis. A number of themes emerge, such as later experiences with violence, including sexual abuse as a child; family difficulties in speaking about the death; the need to learn about the homicide as an adult as well as a need to reconnect with and forgive the assailant; and the importance of a caring adult to provide stability.
Conceptualizing Functional Cognition in Stroke
Authors: Donovan Neila J. , Kendall Diane L. , Heaton Shelley C. , Kwon Sooyeon , Velozo Craig A. , Duncan Pamela W.
Published: August 2007

Background. Up to 65% of individuals demonstrate poststroke cognitive impairments, which may increase hospital stay and caregiver burden. Randomized stroke clinical trials have emphasized physical recovery over cognition. Neuropsychological assessments have had limited utility in randomized clinical trials. These issues accentuate the need for a measure of functional cognition (the ability to accomplish everyday activities that rely on cognitive abilities, such as locating keys, conveying information, or planning activities). Objective. The aim of the study was to present the process used to establish domains of functional cognition for development of computer adaptive measure of functional cognition for stroke. Methods. Functional cognitive domains involved in identifying relevant neuropsychological constructs from the literature were conceptualized and finalized after advisory panel feedback from experts in neurology, neuropsychology, aphasiology, clinical trials, and epidemiology. Results. The following 17 domains were proposed: receptive aphasia, expressive aphasia, agraphia, alexia, calculation, visuospatial, visuoperceptual, visuoconstruction, attention, language usage, executive functions, orientation, processing speed, memory, working memory, mood, awareness and abstract reasoning. The advisory panel recommended retaining the first 12 domains. Recommended changes included: to address only encoding and retrieval of recent information in the memory domain; to add domains for limb apraxia and poststroke depression; and to keep orientation as a separate domain or reclassify it under memory or attention. The final 10 domains included: language, reading and writing, numeric/calculation, limb praxis, visuospatial function, social use of language, emotional function, attention, executive function, and memory. Conclusion. Conceptualizing domains of functional cognition is the first step in developing a computer adaptive measure of functional cognition for stroke. Additional steps include developing, refining, and field-testing items, psychometric analysis, and computer adaptive test programming.
Mutations of the ELA2 gene found in patients with severe congenital neutropenia induce the unfolded protein response and cellular apoptosis
Authors: Grenda David S. , Murakami Mark , Ghatak Jhuma , Xia Jun , Boxer Laurence A. , Dale David , Dinauer Mary C. , Link Daniel C.
Published: August 2007

Severe congenital neutropenia (SCN) is an inborn disorder of granulopoiesis. Mutations of the ELA2 gene encoding neutrophil elastase (NE) are responsible for most cases of SCN and cyclic neutropenia (CN), a related but milder disorder of granulopoiesis. However, the mechanisms by which these mutations disrupt granulopoiesis are unclear. We hypothesize that the ELA2 mutations result in the production of misfolded NE protein, activation of the unfolded protein response (UPR), and ultimately apoptosis of granulocytic precursors. Expression of mutant NE but not wild-type NE strongly induced BiP/GRP78 mRNA expression and XBP1 mRNA splicing, 2 classic markers of the UPR. The magnitude of UPR activation by a specific ELA2 mutation correlated with its associated clinical phenotype. Consistent with the UPR model, expression of mutant NE in primary human granulocytic precursors increased expression of CHOP (DDITS) and induced apoptosis in a protease-independent fashion. Most strikingly, UPR activation and decreased NE protein expression were detected in primary granulocytic precursors from SCN patients. Collectively, these data provide strong support for a UPR model of SCN disease pathogenesis and place SCN in a growing list of human diseases caused by misfolded proteins.
The Akt pathway regulates survival and homing in Waldenstrom macroglobulinemia
Authors: Leleu Xavier , Jia Xiaoying , Runnels Judith , Ngo Hai T. , Moreau Anne-Sophie , Farag Mena , Spencer Joel A. , Pitsillides Costas M. , Hatjiharissi Evdoxia , Roccaro Aldo , O'Sullivan Garrett , McMillin Douglas W. , Moreno Daisy , Kiziltepe Tanyel , Carrasco Ruben , Treon Steven P. , Hideshima Teru , Anderson Kenneth C. , Lin Charles P. , Ghobrial Irene M.
Published: August 2007

Waldenstrom macroglobulinemia (WM) is an incurable low-grade lymphoplasmacytic lymphoma. We demonstrate up-regulated Akt activity in WM, and that Akt down-regulation by Akt knockdown and the inhibitor perifosine leads to significant inhibition of proliferation and induction of apoptosis in WM cells in vitro, but not in normal donor peripheral blood and hematopoietic progenitors. Importantly, down-regulation of Akt induced cytotoxicity of WM cells in the bone marrow microenvironment (BMM) context. Perifosine induced significant reduction in WM tumor growth in vivo in a subcutaneous xenograft model through inhibition of Akt phosphorylation and downstream targets. We also demonstrated that Akt pathway down-regulation inhibited migration and adhesion in vitro and homing of WM tumor cells to the BMM in vivo. Proteomic analysis identified other signaling pathways modulated by perifosine, such as activation of ERK MAPK pathway, which induces survival of tumor cells. Interestingly, MEK inhibitor significantly enhanced perifosine-induced cytotoxicity in WM cells. Using Akt knockdown experiments and specific Akt and PI3K inhibitors, we demonstrated that ERK activation is through a direct effect, rather than feedback activation, of perifosine upstream ERK pathway. These results provide understanding of biological effects of Akt pathway in WM and provide the framework for clinical evaluation of perifosine in WM patients.