bluuebunny/crossref_metadata_2025 huggingface dataset:
Poststroke Depression
Authors: Berg Anu , Palomäki Heikki , Lehtihalmes Matti , Lönnqvist Jouko , Kaste Markku
Published: January 2003

Background and Purpose—

This prospective study was designed to examine the course, associates, and predictors of depressive symptoms during the first 18 months after stroke.

Methods—

A total of 100 patients were followed up for 18 months after stroke. Depressive symptoms were assessed at 2 weeks and 2, 6, 12, and 18 months after stroke with the Beck Depression Inventory and the Hamilton Rating Scale for Depression, and diagnoses were performed using criteria outlined in the
Diagnostic and Statistical Manual of Mental Disorders
,
Third Edition-Revised
. Stroke severity was assessed with the Scandinavian Stroke Scale and cognitive functions with a comprehensive neuropsychological battery. Patients participated in a randomized clinical trial of antidepressive medication.

Results—

In all, 54% of patients felt at least mildly depressive at some time during the follow-up; 46% of those who were depressive during the first 2 months were also depressive at 12 and/or 18 months. Only 12% of patients were depressive for the first time at 12 or 18 months. The male sex was associated with a more negative change in depressive symptoms during the follow-up. Older age was associated with depressive symptoms during the first 2 months, stroke severity from 6 to 12 months, and the male sex at 18 months. Depressive symptoms were unrelated to the lesion location.

Conclusions—

Depressive symptoms are frequent and they often have a chronic course. Depression is associated with stroke severity and functional impairment, and with the male sex at 18 months. Attention should be focused on the long-term prognosis of mood disturbances and adaptation.
Temporal Relationship Between Apparent Diffusion Coefficient and Absolute Measurements of Cerebral Blood Flow in Acute Stroke Patients
Authors: Lin Weili , Lee Jin-Moo , Lee Yueh Z. , Vo Katie D. , Pilgram Thomas , Hsu Chung Y.
Published: January 2003

Background and Purpose—

Diffusion-weighted imaging (DWI) has been established as a marker of acute ischemic brain injury. We sought to determine the relationship between cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) and to explore whether the elapsed time between MRI acquisition and symptom onset alters this relation in acute stroke patients.

Methods—

Sixteen acute stroke patients were studied with DWI and perfusion-weighted imaging, from which ADC and CBF were calculated. ADC values were normalized (nADC) to the contralateral, nonischemic hemisphere and then correlated pixel by pixel with CBF within a region of interest defined by abnormal transit time. To explore potential temporal effects on the relationship between CBF and nADC, patients were divided into 2 groups based on the duration between symptom onset and MR imaging for data analysis: group A, 2 to 4 hours (n=8), and group B, 4.5 to 6.5 hours (n=8).

Results—

nADC was plotted against CBF for each pixel in all 16 subjects, and a composite relationship was derived. After a gradual decline, an abrupt drop in nADC occurred below a CBF threshold value of 21 mL · min
−1
· 100 g
−1
. When subjects were divided into early and late imaging groups, the group of patients imaged earlier (group A) had a lower threshold (15 mL · min
−1
· 100 g
−1
) than the group imaged later (group B, 24 mL · min
−1
· 100 g
−1
).

Conclusions—

Our results demonstrate that a relationship between nADC and CBF exists in the ischemic brain and that ADC values alone may provide useful information in predicting perfusion status. However, this relationship may change with elapsing time between stroke onset and imaging.
Establishing Data Elements for the Paul Coverdell National Acute Stroke Registry
Authors: Wattigney Wendy A. , Croft Janet B. , Mensah George A. , Alberts Mark J. , Shephard Timothy J. , Gorelick Philip B. , Nilasena David S. , Hess David C. , Walker Michael D. , Hanley Daniel F. , Shwayder Patti , Girgus Meighan , Neff Linda J. , Williams Janice E. , LaBarthe Darwin R. , Collins Janet L.
Published: January 2003

Background and Purpose—

Stroke is the third-leading cause of death and a leading cause of disability in adults in the United States. In recent years, leaders in the stroke care community identified a national registry as a critical tool to monitor the practice of evidence-based medicine for acute stroke patients and to target areas for continuous quality of care improvements. An expert panel was convened by the Centers for Disease Control and Prevention to recommend a standard list of data elements to be considered during development of prototypes of the Paul Coverdell National Acute Stroke Registry.

Methods—

A multidisciplinary panel of representatives of the Brain Attack Coalition, professional associations, nonprofit stroke organizations, and federal health agencies convened in February 2001 to recommend key data elements. Agreement was reached among all participants before an element was added to the list.

Results—

The recommended elements included patient-level data to track the process of delivering stroke care from symptom onset through transport to the hospital, emergency department diagnostic evaluation, use of thrombolytic therapy when indicated, other aspects of acute care, referral to rehabilitation services, and 90-day follow-up. Hospital-level measures pertaining to stroke center guidelines were also recommended to augment patient-level data.

Conclusions—

Routine monitoring of the suggested parameters could promote community awareness campaigns, support quality improvement interventions for stroke care and stroke prevention in each state, and guide professional education in hospital and emergency system settings. Such efforts would reduce disability and death among stroke patients.
Risk Factors for Aneurysmal Subarachnoid Hemorrhage in Aomori, Japan
Authors: Ohkuma Hiroki , Tabata Hidefumi , Suzuki Shigeharu , Islam Md Shafiqul
Published: January 2003

Background and Purpose—

Japan is known to have an incidence of aneurysmal subarachnoid hemorrhage (SAH) as high as that in Finland, where SAH is especially common. However, the risk factors for SAH in Japan are unknown. The purpose of this study was to identify the risk factors and then examine their possible roles in cases of SAH in Japan.

Methods—

Case-control data were collected in the Aomori prefecture between June 2000 and May 2001 and in the Shimokita area between 1989 and 1998. A history of hypertension, cigarette smoking, alcohol consumption, hypercholesterolemia, and diabetes mellitus were examined as possible risk factors for SAH by using stepwise logistic regression analysis.

Results—

Stepwise logistic regression analysis showed that a history of hypertension and current smoking increased the risk of SAH and that a history of hypercholesterolemia decreased the risk of SAH. Alcohol consumption and a history of diabetes mellitus were excluded from the model, because their log-likelihood ratios were not significant. The adjusted odds ratios, obtained by forcing matching factors, were 2.29 for a history of hypertension (95% CI, 1.66 to 3.16), 3.12 for current smoking (95% CI, 2.05 to 4.77), and 0.41 for a history of hypercholesterolemia (95% CI, 0.24 to 0.71). The prevalence of hypertension in control subjects was 27% in men and 31% in women, whereas the prevalence of cigarette smoking in control subjects was 46% in men and 9% in women.

Conclusions—

Hypertension and cigarette smoking seem to be independent risk factors for SAH in Japan. The high prevalence of hypertension in both sexes and the high prevalence of cigarette smoking in men in the general population might contribute to the high incidence of SAH in Japan.
Yield of Screening for CADASIL Mutations in Lacunar Stroke and Leukoaraiosis
Authors: Dong Yanbin , Hassan Ahamad , Zhang Zhongyi , Huber Dionne , Dalageorgou Chrysoula , Markus Hugh S.
Published: January 2003

Background and Purpose—

Cerebral autosomal dominant arteriopathy subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic disorder typified by early onset lacunar strokes, subcortical dementia, psychiatric disturbances, and migraine. Mutations in the
Notch3
gene are responsible. Atypical phenotypes have been recognized, and the disease is probably underdiagnosed in the wider stroke population. Therefore, we determined the yield of screening for
Notch3
mutations in lacunar stroke with or without leukoaraiosis.

Methods—

Two hundred eighteen consecutive patients were studied. All had brain and carotid imaging. Polymerase chain reaction-single-stranded conformational polymorphism analysis was used to screen exons 3, 4, 5, and 6 of the
Notch3
gene for mutations and polymorphisms.

Results—

A single mutation in exon 4 (C697T) was identified in a young patient, giving an overall carrier frequency of 0.05% (95% CI, 0.0 to 2.0). For patients with onset of lacunar stroke at ≤65 years and leukoaraiosis, the yield was 2.0% (95% CI, 0.4 to 10.9).

Conclusions—

Notch3
mutations are rare in patients with typical strokes due to cerebral small-vessel disease. In the absence of classic features suggestive of CADASIL, screening for
Notch3
mutations has a low yield.
HMG-CoA Reductase Inhibitor Has Protective Effects Against Stroke Events in Stroke-Prone Spontaneously Hypertensive Rats
Authors: Kawashima Seinosuke , Yamashita Tomoya , Miwa Yoichi , Ozaki Masanori , Namiki Masayuki , Hirase Tetsuaki , Inoue Nobutaka , Hirata Ken-ichi , Yokoyama Mitsuhiro
Published: January 2003

Background and Purpose—

Recent clinical studies suggest that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) exert protective effects against nonhemorrhagic stroke. In a murine cerebral ischemia model produced by occlusion of the middle cerebral artery, statins were shown to reduce infarct size. However, the effect of statins on hypertension-based stroke is unknown. The purpose of this study is to clarify the effect of a statin on stroke in stroke-prone spontaneously hypertensive rats (SHR-SP), in which both cerebral hemorrhage and infarction occur.

Methods—

We treated SHR-SP chronically from 4 weeks of age with cerivastatin (2 mg/kg per day by gavage) or vehicle. The physiological parameters, the incidence of stroke-associated symptoms, and mortality were assessed.

Results—

At 14 weeks of age, the incidence (13±3% versus 37±8%;
P
<0.01) and the size of stroke (1.6±0.2 versus 2.2±0.1 arbitrary units;
P
<0.01) were significantly decreased by cerivastatin, although blood pressure and plasma cholesterol levels were not different. Moreover, stroke-associated symptoms and early mortality of SHR-SP were markedly reduced in the statin-treated group (mortality at the age of 15 weeks: 15% versus 50%;
P
<0.05). Statin treatment significantly reduced superoxide production from nonstroke parenchyma of brain and infiltration of inflammatory cells to the stroke lesions.

Conclusions—

Our data show that a high dose of statin exerts protection against hypertension-based stroke and ameliorates the disease severity via inhibition of superoxide production and modulation of inflammation in brain.
Ischemic Preconditioning in the Hippocampus of a Knockout Mouse Lacking SUR1-Based K
ATP
Channels
Authors: Muñoz Alvaro , Nakazaki Mitsuhiro , Goodman J. Clay , Barrios Roberto , Onetti Carlos G. , Bryan Joseph , Aguilar-Bryan Lydia
Published: January 2003

Background and Purpose—

ATP-sensitive K
+
(K
ATP
) channels have been implicated in the mechanism of neuronal ischemic preconditioning. To evaluate the role of neuronal/β–cell-type K
ATP
channels, SUR1 null (Sur1KO) mice lacking (K
IR
6.x/SUR1)
4
K
ATP
channels were subjected to a preconditioning protocol with the use of double carotid occlusion.

Methods—

Wild-type C57BL/6 and Sur1KO mice were subjected to a double carotid block for 40 minutes with or without a 20-minute preconditioning block. After a 10-day reperfusion period, damage was assessed histologically in the hippocampal CA1, CA2, and CA3 areas and in the dentate gyrus. The neuroprotective effects of intracerebroventricular injections of diazoxide, which selectively affects mitochondria versus opening SUR1-type K
ATP
channels, and 5-hydroxydecanoate, a selective blocker of mitoK
ATP
channels, were evaluated with the same protocol.

Results—

Neurons in the CA1 region of both Sur1KO and wild-type animals subjected to a 20-minute ischemic insult were protected equally from neuronal damage produced by a subsequent 40-minute ischemic period. Pretreatment with diazoxide protected both Sur1KO and wild-type neurons, while 5-hydroxydecanoate augmented neurodegeneration in both strains of animals when administered before a 20-minute bout of ischemia.

Conclusions—

SUR1-based K
ATP
channels are not obligatory for neuronal preconditioning or augmentation of neurodegeneration by 5-hydroxydecanoate.
CP-465,022, a Selective Noncompetitive AMPA Receptor Antagonist, Blocks AMPA Receptors but Is Not Neuroprotective In Vivo
Authors: Menniti Frank S. , Buchan Alistair M. , Chenard Bertrand L. , Critchett Donald J. , Ganong Alan H. , Guanowsky Victor , Seymour Patricia A. , Welch Willard M.
Published: January 2003

Background and Purpose—

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor inhibition has been hypothesized to provide neuroprotective efficacy after cerebral ischemia on the basis of the activity in experimental ischemia models of a variety of compounds with varying selectivity for AMPA over other glutamate receptor subtypes. CP-465,022 is a new, potent, and selective noncompetitive AMPA receptor antagonist. The present study investigated the ability of this compound to reduce neuronal loss after experimental cerebral ischemia to probe the neuroprotective potential of AMPA receptor inhibition.

Methods—

To demonstrate that CP-465,022 gains access to the brain, the effects of systemic administration of CP-465,022 were investigated on AMPA receptor-mediated electrophysiological responses in hippocampus and on chemically induced seizures in rats. The compound was then investigated for neuroprotective efficacy in rat global and focal ischemia models at doses demonstrated to be maximally effective in the electrophysiology and seizure models.

Results—

CP-465,022 potently and efficaciously inhibited AMPA receptor-mediated hippocampal synaptic transmission and the induction of seizures. However, at comparable doses, CP-465,022 failed to prevent CA1 neuron loss after brief global ischemia or to reduce infarct volume after temporary middle cerebral artery occlusion.

Conclusions—

Given the high selectivity of CP-465,022 for AMPA over kainate and
N
-methyl-
d
-aspartate subtypes of glutamate receptors, the lack of neuroprotective efficacy of the compound calls into question the neuroprotective efficacy of AMPA receptor inhibition after ischemia.
Utility of the NIH Stroke Scale as a Predictor of Hospital Disposition
Authors: Schlegel Daniel , Kolb Stephen J. , Luciano Jean M. , Tovar Jennifer M. , Cucchiara Brett L. , Liebeskind David S. , Kasner Scott E.
Published: January 2003

Background and Purpose—

Early identification of stroke patients in need of rehabilitation or long-term nursing facility (NF) care may promote more efficient use of health care resources and lead to better outcomes. The NIH Stroke Scale (NIHSS) is an attractive candidate predictor of disposition because it is widely used, is easily learned, and can be performed rapidly on admission.

Methods—

We present a retrospective study of stroke patients admitted within 24 hours of symptom onset to a university hospital from March through June 2000. Medical records were reviewed for demographic information, stroke type, prestroke living arrangement and independence, initial NIHSS, and medical complications during hospitalization.

Results—

Among 94 patients evaluated during the study period, 59% were discharged home, 30% to rehabilitation, and 11% to NF. In multivariate analyses, disposition was associated only with initial NIHSS. For each 1-point increase in NIHSS, the likelihood of going home was significantly reduced (odds ratio, 0.79; 95% CI, 0.70 to 0.89,
P
<0.001). Categorization of NIHSS was also predictive of disposition, with NIHSS ≤5 being most strongly associated with discharge home, NIHSS 6 to 13 with rehabilitation, and NIHSS >13 with NF (
P
<0.001). Although no other baseline characteristics predicted disposition, major medical complications during hospitalization tended to reduce the odds of going home (odds ratio, 0.30; 95% CI, 0.08 to 1.0,
P
=0.07).

Conclusion—

The NIHSS predicts postacute care disposition among stroke patients. Predicting disposition on the first day of admission may facilitate the time-consuming and costly process of securing a bed at rehabilitation or NF, and perhaps decrease unnecessary length of stay in acute care settings.
Relation Between Serum Albumin and Carotid Atherosclerosis
Authors: Djoussé Luc , Rothman Kenneth J. , Cupples L. Adrienne , Arnett Donna K. , Ellison R. Curtis
Published: January 2003

Background and Purpose—

Lower concentrations of albumin have been positively related to coronary disease. The aim of this project was to assess the association between serum albumin and carotid atherosclerosis.

Methods—

B-mode ultrasound was used to assess carotid plaques and intima-media thickness (IMT) among white subjects from 592 randomly ascertained families in the National Heart, Lung, and Blood Institute Family Heart Study. Logistic regression was used to estimate prevalence odds ratios of any carotid plaques.

Results—

Of the 2072 persons studied, 47% were men. Higher serum albumin was associated with younger age, lower body mass index, and lower prevalence of hypertension and coronary disease. Lower serum albumin levels were not associated with an increased odds of carotid plaques. From the lowest to the highest quartile of albumin, multivariate adjusted odds ratios for the prevalence of any carotid plaques were 1.05 (95% CI, 0.59 to 1.86), 1.34 (95% CI, 0.78 to 2.32), 1.03 (95% CI, 0.52 to 1.86), and 1.0 (reference), respectively, in men and 0.71 (95% CI, 0.40 to 1.26), 0.76 (95% CI, 0.42 to 1.36), 0.79 (95% CI, 0.46 to 1.36), and 1.0, respectively, in women. Similarly, in a linear regression model adjusted for demographic, lifestyle, and metabolic factors, serum albumin was not associated with carotid IMT. When the first 3 were compared with the highest quartile of serum albumin, regression coefficients for internal carotid IMT were 0.06458 (SE, 0.06408), 0.07205 (SE, 0.05469), and 0.000773 (SE, 0.05687), respectively, for men and −0.01795 (SE, 0.05085), −0.08501 (SE, 0.04800), and 0.009528 (SE, 0.04622), respectively, for women.

Conclusions—

Our data suggest that lower serum albumin levels are not associated with an increased odds of prevalent carotid atherosclerosis in either men or women.
Cerebral Hypoperfusion and Delayed Hippocampal Response After Induction of Adult Kaolin Hydrocephalus
Authors: Klinge Petra Margarete , Samii Amir , Mühlendyck Annette , Visnyei Koppany , Meyer Geerd-Jürgen , Walter Gerhard Franz , Silverberg Gerald D. , Brinker Thomas
Published: January 2003

Background and Purpose—

In chronic hydrocephalus, a role for tissue hypoxia resulting from cerebrovascular compression is suggested. The purpose of this study was to evaluate whether changes in cerebral blood flow (CBF) in the time course of adult kaolin-induced hydrocephalus correlated with immunohistochemical neuronal responses.

Methods—

In 46 adult Sprague-Dawley rats, kaolin hydrocephalus was induced and immunostaining of neurofilament protein (NF68), synaptophysin (SYN38), and neuronal nitric oxide synthase (NOS) was performed at 2 (short term), 4 (intermediate term), and 6 and 8 (long term) weeks. Local CBF was measured quantitatively by [
14
C]iodoantipyrine ([
14
C]IAP) autoradiography in the short-term stage and in both long-term stages.

Results—

At 2 weeks, neuronal NOS immunoreactivity was globally increased in cortical areas and within the hippocampus. Four weeks after hydrocephalus induction, a reactive increase of SYN38 and NF68 immunoreactivity in the periventricular cortex was seen. At 6 and 8 weeks, when the ventricular size was decreasing, immunohistochemical changes in the hippocampus became most evident. A maintained toxic NOS reactivity in the CA1 subfield was accompanied by a loss of NF68 staining. In the CA3 subfield, however, focal increases in NF68 and SYN38 immunoreactivity were found. Cortical and hippocampal blood flow showed prolonged decreases of 25% to 55% compared with control animals. At 8 weeks, control levels were reached.

Conclusions—

The observed temporary CBF decrease appears to correlate with an early global neuronal ischemic response. In addition, it may also account for the delayed selective response of ischemia-vulnerable structures, eg, hippocampus, in chronic adult kaolin-induced hydrocephalus.
Early-Onset Carotid Atherosclerosis Is Associated With Increased Intima-Media Thickness and Elevated Serum Levels of Inflammatory Markers
Authors: Magyar Mária T. , Szikszai Zita , Balla József , Valikovics Attila , Kappelmayer János , Imre Sándor , Balla György , Jeney Viktória , Csiba László , Bereczki Dániel
Published: January 2003

Background and Purpose—

Several factors have been held responsible for the development of atherosclerosis. To avoid the masking effect of age, we evaluated correlates of carotid atherosclerosis in patients <55 years of age.

Methods—

Plasma lipids, oxidative resistance of low-density lipoprotein, homocysteine, inflammatory markers, plasma viscosity, and red cell deformability were measured in fasting blood samples of 100 subjects: 45 patients with >30% stenosis of the internal carotid artery, 20 patients with carotid occlusion, and 35 control subjects. Stenosis and intima-media thickness (IMT) of the carotid artery were evaluated by duplex ultrasound.

Results—

White blood cell (WBC) count, plasma fibrinogen, C-reactive protein (CRP), and lipoprotein(a) levels were significantly higher in patients than in control subjects, and patients had increased IMT (
P
<0.01 for all comparisons). There was a tendency for higher homocysteine levels in patients. Smokers had higher WBC, fibrinogen, and CRP levels. After the effect of smoking was controlled for, WBC count, natural logarithmic transform of homocysteine, and online-measured IMT remained significantly higher in patients than in control subjects. WBC, fibrinogen, and CRP levels were highest in the highest IMT quartile (
P
=0.012,
P
=0.007, and
P
=0.036, respectively).

Conclusions—

Inflammatory markers and homocysteine have a more important role than lipid factors in early-onset carotid atherosclerosis. We cannot recommend the measurement of low-density lipoprotein peroxidation as a routine screening test to identify high-risk patients for early-onset carotid atherosclerosis. The confounding effect of smoking on inflammatory markers should be considered in studies on atherosclerosis.
Determination of Lipid Profiles and Use of Statins in Patients With Ischemic Stroke or Transient Ischemic Attack
Authors: Lalouschek Wolfgang , Lang Wilfried , Greisenegger Stefan , Müllner Marcus
Published: January 2003

Background and Purpose—

Statins reduce the risk of myocardial infarction and stroke in patients with vascular disease. Inappropriate serum lipid determination and underuse of statins have been documented in patients with coronary artery disease. Evaluation of hyperlipidemia and treatment with statins in patients with recent ischemic cerebrovascular events have not yet been investigated.

Methods—

We determined the frequency of total cholesterol (TC) and low-density lipoprotein cholesterol measurements and the use of statins in a multicenter prospective cohort study of 1743 patients with acute ischemic stroke or transient ischemic attack (TIA). Using multivariate logistic regression analysis, we determined the influence of several clinical variables on lipid measurements and the prescription of statins at hospital discharge.

Results—

TC was measured in 90% and low-density lipoprotein cholesterol was measured in 48% of the patients. Differences between the centers accounted for most of the observed variability in a multivariate model. Statin prescription also varied widely between the centers. The prescription of a statin at discharge was most strongly associated with statin intake before the event and with increasing TC levels; elderly patients received statins less often. Coronary artery disease, peripheral artery disease, and other manifestations of atherosclerosis were not independently associated with the use of statins; 68% of the patients with manifest atherosclerosis and TC levels >200 mg/dL were discharged without a statin.

Conclusions—

The determination of serum lipid profiles varies widely between different centers. Statins are highly underused in patients with recent ischemic stroke or TIA, particularly in those in whom statins are indicated according to existing recommendations (eg, patients with additional coronary artery disease and hypercholesterolemia). Currently, international guidelines concerning the use of statins are not adequately implemented in clinical practice in patients with stroke or TIA.
Periodontal Disease, Tooth Loss, and Incidence of Ischemic Stroke
Authors: Joshipura Kaumudi J. , Hung Hsin-Chia , Rimm Eric B. , Willett Walter C. , Ascherio Alberto
Published: January 2003

Background and Purpose—

Periodontal and other infections have been suggested as potential risk factors for stroke. This study evaluates periodontal disease and tooth loss as risk factors for ischemic stroke.

Methods—

The study population consisted of 41 380 men who were free of cardiovascular disease and diabetes at baseline. Periodontal disease history was assessed by mailed validated questionnaires. During 12 years of follow-up, stroke incidence was assessed and subclassified by use of medical history, medical records, and imaging reports. Hazard ratios (HRs) were adjusted for age, amount smoked, obesity, alcohol, exercise, family history of cardiovascular disease, multivitamin use, vitamin E use, profession, baseline reported hypertension, and hypercholesterolemia. Sex and socioeconomic status were inherently controlled for by restriction. Confounding variables were updated in the analyses for each 2-year follow-up interval.

Results—

We documented 349 ischemic stroke cases during the follow-up period. Men who had ≤24 teeth at baseline were at a higher risk of stroke compared to men with ≥25 teeth (HR=1.57; 95% CI, 1.24 to 1.98). There was little evidence of an increased risk with recent tooth loss during follow-up. A modest association was seen between baseline periodontal disease history and ischemic stroke (HR=1.33; 95% CI, 1.03 to 1.70). Addition of dietary factors to the model changed the HR only slightly.

Conclusions—

Our results suggest that periodontal disease and fewer teeth may be associated with increased risk of ischemic stroke.
The KGB, Perestroika, and the Collapse of the Soviet Union
Authors: Knight Amy
Published: January 2003

This article examines the role of the Committee on State Security (KGB) during the turbulent six-and-a-half years under Mikhail Gorbachev, from March 1985 to December 1991. Contrary to popular impressions, the KGB was never an independent actor in the Soviet system; it acted at the behest of the Communist Party. When Vladimir Kryuchkov replaced Viktor Chebrikov as head of the KGB in 1986, the move signaled what was intended to be a new role for the KGB. But as the reforms launched by Gorbachev became more radical, and as political instability in the Soviet Union became widespread, many in the KGB grew anxious about the possible fragmentation of the country. These concerns were instrumental in the decision by Kryuchkov and other high-ranking KGB officials to organize a hardline coup in August 1991. Even then, however, the KGB was not truly independent of the party. On the contrary, KGB officials were expecting—and then desperately hoping—that Gorbachev would agree to order an all-out crackdown. Because Gorbachev was unwilling to take a direct part in mass repression, Kryuchkov lacked the authority he was seeking to act. As a result, the attempted coup failed, and the KGB was forced onto the defensive. Shortly before the Soviet state was dissolved, the KGB was broken up into a number of agencies that soon came under Russia's direct control.
The August 1991 Coup and Its Impact on Soviet Politics
Authors: Dunlop John B.
Published: January 2003

A book published by the author in 1993 contained a lengthy chapter on the August 1991 coup attempt in the Soviet Union. This article builds on and updates that chapter, making use of a trove of newly available documents and memoirs. The article discusses many aspects of the coup attempt, but it particularly seeks to explain why the coup failed and what the implications were for the Soviet Union. The events of December 1991 that culminated in the dissolution of the Soviet Union were the direct result of changes set in motion by the failed coup. The major state and party institutions that might ordinarily have tried to hold the country together—the Communist Party apparatus, the secret police, the military-industrial complex, the Ministry of Defense, and the state administrative organs—all were compromised by their participation in the coup. As a result, when events pushed the Soviet Union toward collapse there was no way of staving off that outcome.
Dimerization of Incomplete Cuboidal Mo3S4 Units via α,ω-Dicarboxylates, and Their Supramolecular Architectures through Intermolecular S···S and C–H···S Interactions
Authors: Tang Yanhong , Yao Yuangen , Wu Ling , Qin Yeyan , Kang Yao , Li Zhaoji
Published: January 2003

Two novel hexanuclear molybdenum cluster compounds [Mo3S4(dtp)3(L)]2[η2-μ-OOC(CH2)nCOO-μ-η2] (n = 4, L = DMF for 1; n = 3, L = DMSO for 2) have been synthesized by reaction of Mo3S4(dtp)3(ClCH2COO)(Py) with α,ω-dicarboxylates. Intermolecular S···S and C–H···S interactions are observed, yielding two different two-dimensional supramolecular structures.
A minimal axisymmetric hurricane model
Authors: Mai Nguyen Chi , Smith Roger K. , Zhu Hongyan , Ulrich Wolfgang
Published: January 2003

Solutions of an axisymmetric version of the minimal three‐dimensional numerical model of a tropical cyclone developed by Zhu et al. (2001) are described and compared with those of the three‐dimensional model. Vortex evolution is similar in the two models during the early stages of intensification, but the period of rapid intensification occurs earlier in the axisymmetric model due to the higher effective resolution obtained using a staggered grid. There are marked differences at later times, when, in the three‐dimensional model, asymmetric structures develop. The findings are compared with those of an earlier study by Anthes (1972).

The axisymmetric model is used to investigate certain fundamental aspects of tropical‐cyclone dynamics, including the emergence of a region of supergradient winds in the boundary layer and the evolution of regions satisfying necessary conditions for inertial and barotropic instability. Supergradient winds develop in the boundary layer within a radius of about 100 km of the vortex axis at an early stage of evolution and appear to be a natural feature of the vortex boundary layer. The development of flow regions satisfying necessary conditions for inertial and barotropic instability occur later, and may be attributed inter alia to the upward transfer of air with relatively high angular momentum, from the boundary layer to the middle and upper layers, by the secondary circulation of the vortex, and the downward transfer of air with relatively low angular momentum to the middle layer. A linear analysis of a two‐layer slab‐symmetric flow suggests why inertial instability does not occur in the axisymmetric model. Barotropic instability does not appear to be the mechanism responsible for the growth of asymmetries in the calculations using the three‐dimensional version of the model. Copyright © 2002 Royal Meteorological Society.
Order‐based fitness functions for genetic algorithms applied to relevance feedback
Authors: López‐Pujalte Cristina , Guerrero‐Bote Vicente P. , de Moya‐Anegón Félix
Published: January 2003

Recently there have been appearing new applications of genetic algorithms to information retrieval, most of them specifically to relevance feedback. The evolution of the possible solutions are guided by fitness functions that are designed as measures of the goodness of the solutions. These functions are naturally the key to achieving a reasonable improvement, and which function is chosen most distinguishes one experiment from another. In previous work, we found that, among the functions implemented in the literature, the ones that yield the best results are those that take into account not only when documents are retrieved, but also the order in which they are retrieved. Here, we therefore evaluate the efficacy of a genetic algorithm with various order‐based fitness functions for relevance feedback (some of them of our own design), and compare the results with the Ide dec‐hi method, one of the best traditional methods.
A profile of faculty reading and information‐use behaviors on the cusp of the electronic age
Authors: Belefant‐Miller Helen , King Donald W.
Published: January 2003

The majority of a university faculty's work deals with information or knowledge—finding, getting, reading, and using it. We analyzed the demographic portion of a library use survey given to faculty and staff of the University of Tennessee at Knoxville (UTK) to obtain a profile of information‐related activities carried out by university faculty. Journal articles were the predominant document type that faculty both read and authored. Faculty averaged 4.2 journal subscriptions per person, of which 84% were paid for personally. Twenty‐five percent of the faculty had obtained some funds for information products and of those funded, the median amount provided was $500. Faculty spent 24 minutes per day using e‐mail and 78 minutes per week using non‐e‐mail computer network. Faculty reported publishing 3.0 journal articles per year and 31% of the faculty had won an award for professional contributions in the previous 2 years.
Informational environments: Organizational contexts of online information use
Authors: Lamb Roberta , King John Leslie , Kling Rob
Published: January 2003

Before the Web, the story of online information services was largely one of over‐estimates and unmet expectations. This study examines sustained use and non‐use of online services within organizations in a way that overcomes limitations of the traditional approaches that repeatedly led to exuberant usage projections. By adopting an open‐systems view, we see that firms in highly technical and highly institutional environments have many more incentives to gather data and go online than do firms in low‐tech, unregulated industries. But firms make important choices about partnering and outsourcing that can shift informational activities across organizational boundaries. Our analysis focuses on the informational environments of firms in three industries: law, real estate and biotech/pharmaceuticals. This environmental model provides richer conceptualizations about the use of information and communication technologies, including Internet technologies, and better projections about future use. In support of our analysis, we briefly discuss insights from an ongoing intranets study informed by an informational environments perspective.
NLPIR: A theoretical framework for applying natural language processing to information retrieval
Authors: Zhou Lina , Zhang Dongsong
Published: January 2003

The role of information retrieval (IR) in support of decision making and knowledge management has become increasingly significant. Confronted by various problems in traditional keyword‐based IR, many researchers have been investigating the potential of natural language processing (NLP) technologies. Despite widespread application of NLP in IR and high expectations that NLP can address the problems of traditional IR, research and development of an NLP component for an IR system still lacks support and guidance from a cohesive framework. In this paper, we propose a theoretical framework called NLPIR that aims at integrating NLP into IR and at generalizing broad application of NLP in IR. Some existing NLP techniques are described to validate the framework, which not only can be applied to current research, but is also envisioned to support future research and development in IR that involve NLP.
Maillard reactions and increased enzyme inactivation during oligosaccharide synthesis by a hyperthermophilic glycosidase
Authors: Bruins M. E. , Van Hellemond E. W. , Janssen A. E. M. , Boom R. M.
Published: January 2003

The thermostable Pyrococcus furiosus β‐glycosidase was used for oligosaccharide production from lactose in a kinetically controlled reaction. Our experiments showed that higher temperatures are beneficial for the absolute as well as relative oligosaccharide yield. However, at reaction temperatures of 80°C and higher, the inactivation rate of the enzyme in the presence of sugars was increased by a factor of 2 compared to the inactivation rate in the absence of sugars. This increased enzyme inactivation was caused by the occurrence of Maillard reactions between the sugar and the enzyme. The browning of our reaction mixture due to Maillard reactions was modeled by a cascade of a zeroth‐ and first‐order reaction and related to enzyme inactivation. From these results we conclude that modification of only a small number of amino groups already gives complete inactivation of the enzyme. © 2003 Wiley Periodicals. Biotechnol Bioeng 81:546–552, 2003.
Simulation of growth and detachment in biofilm systems under defined hydrodynamic conditions
Authors: Horn Harald , Reiff Helmut , Morgenroth Eberhard
Published: January 2003

Detachment from biofilms was evaluated using a mixed culture biofilm grown on primary wastewater in a tube reactor. The growth of biofilms and the detachment of biomass from biofilms are strongly influenced by hydrodynamic conditions. In a long‐term study, three biofilms were cultivated in a biofilm tube reactor. The conducted experiments of biofilm growth and detachment can be divided into three phases: 1) an exponential phase with a rapid increase of the biofilm thickness, 2) a quasi‐steady‐state with spontaneous fluctuation of the biofilm thickness between 500 and 1,200 μm in the investigated biofilm systems, and 3) a washout experiment with increased shear stress in three to four steps after several weeks of quasi‐steady‐state. Whereas the biofilm thickness during the homogeneous growth phase can be regarded constant throughout the reactor, it was found to be very heterogeneous during the quasi‐steady‐state and the washout experiments. Growth and detachment during all three phases was simulated with the same one‐dimensional biofilm model. For each of the three phases, a different detachment rate model was used. During the homogeneous growth phase, detachment was modeled proportional to the biofilm growth rate. During the quasi‐steady‐state phase, detachment was described by random detachment events assuming a base biofilm thickness. Finally, the washout experiment was simulated with detachment being a function of the biofilm thickness before the increase of the shear stress. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 607–617, 2003.
Anisotropic stretch‐induced hypertrophy in neonatal ventricular myocytes micropatterned on deformable elastomers
Authors: Gopalan Sindhu M. , Flaim Chris , Bhatia Sangeeta N. , Hoshijima Masahiko , Knoell Ralph , Chien Kenneth R. , Omens Jeffrey H. , McCulloch Andrew D.
Published: January 2003

Because cell shape and alignment, cell–matrix adhesion, and cell–cell contact can all affect growth, and because mechanical strains in vivo are multiaxial and anisotropic, we developed an in vitro system for engineering aligned, rod‐shaped, neonatal cardiac myocyte cultures. Photolithographic and microfluidic techniques were used to micropattern extracellular matrices in parallel lines on deformable silicone elastomers. Confluent, elongated, aligned myocytes were produced by varying the micropattern line width and collagen density. An elliptical cell stretcher applied 2:1 anisotropic strain statically to the elastic substrate, with the axis of greatest stretch (10%) either parallel or transverse to the myofibrils. After 24 h, the principal strain parallel to myocytes did not significantly alter myofibril accumulation or expression of atrial natriuretic factor (ANF), connexin‐43 (Cx‐43), or N‐cadherin (by indirect immunofluorescent antibody labeling and immunoblotting) compared with unstretched controls. In contrast, 10% transverse principal strain resulted in continuous staining of actin filaments (rhodamine phalloidin); increased immunofluorescent labeling of ANF, Cx‐43, and N‐cadherin; and upregulation of protein signal intensity by western blotting. By using microfabrication and microfluidics to control cell shape and alignment on an elastic substrate, we found greater effects for transverse than for longitudinal stretch in regulating sarcomere organization, hypertrophy, and cell‐to‐cell junctions. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 578–587, 2003.
Raman and Fourier transform infrared study of phytol effects on saturated and unsaturated lipid multibilayers
Authors: Picquart M. , Lefèvre T.
Published: January 2003

The effects of phytol on DPPC and OPPC multilayers were investigated using FT‐IR and Raman spectroscopy. The results were compared with those obtained with α‐tocopherol (α‐T) and α‐tocopherol acetate (α‐TA). The chain packing was analyzed using Raman intensity ratios measured in the CH2 stretching region, whereas the number of gauche bonds introduced by phytol was estimated by the measure of the FT‐IR absorbance of the CH2 wagging progression modes. It is shown that the chain packing is reduced and that gauche rotamer formation is promoted by phytol in the gel phase. Phytol has a very similar effect on the acyl chains of DPPC to α‐T but does not have the same impact on the CO stretching vibrations of this lipid. The results indicate that phytol perturbs the interfacial region of DPPC causing dehydration or a conformational modification of the ester groups. Furthermore, the modification of the OPPC chain order induced by phytol is slightly different with respect to α‐T. It is concluded that (1) a hydrogen bond between the hydroxyl group of α‐T and the phospholipid carbonyl groups may not necessarily be associated with the stabilization of the membrane, (2) the studied phytyl compounds may be located more or less close to the membrane interface, (3) the presence of the chromanol ring may strongly influence the location of vitamin E within the membrane and, consequently, its capacity to catch free radicals and (4) the hydroxyl group, chroman moiety and phytyl chain all play a crucial role that determines the effects of α‐T on lipid acyl chains and its location within membranes, which in turn can affect its biological function. Copyright © 2002 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering (SERS) of 4‐mercaptobenzoic acid on silver and gold substrates
Authors: Michota A. , Bukowska J.
Published: January 2003

Surface‐enhanced Raman scattering (SERS) spectra were recorded for p‐mercaptobenzoic acid (PMBA) monolayers on Ag and Au surfaces. As evidenced by the relative intensities of the bands corresponding to the symmetric stretching COO− vibration and to the out‐of‐plane vibration of the phenyl ring, the molecules are at least tilted with respect to the surface and simultaneously bonded through the sulfur atom and COO− groups. This situation takes place when modification is carried out from aqueous solutions at natural or alkaline pH and at low concentrations of monomer. At higher concentration of the monomer (>10−3) and/or at acidic pH, carboxylic groups are protonated and PMBA molecules adopt a more vertical configuration. It was also found that rough Ag and Au surfaces that are applied in SERS experiments promote partial decarboxylation of PMBA. Copyright © 2002 John Wiley & Sons, Ltd.
A new version of AgFON substrates for high‐throughput analytical SERS applications
Authors: Stropp J. , Trachta G. , Brehm G. , Schneider S.
Published: January 2003

The drop coating technique was applied to generate thin films of various polymer nanospheres as a basis for the preparation of AgFON (Ag films over nanospheres). In contrast to the well known spin coating technique, the chosen procedure also allows the use of multiwell (microtiter) plates as substrate, thereby opening up the possibility of a high‐throughput analysis technique based on SERS. Employing commercially available spheres of polystyrene (diameter 533 nm) or silica (diameter 470 nm) and an Ag top layer 200 nm thick, SERS spectra of several food dyes were recorded; for Brillant Green (E 142), the detection limit was about 500 pg per well. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies of L‐argininium dinitrate
Authors: Ramaswamy S. , Rajaram R. K. , Ramakrishnan V.
Published: January 2003

The Fourier transform IR and Raman spectra of (C6H16N4O22+·2NO3−) crystal were studied and the observed IR and Raman lines were assigned. There is extensive intermolecular hydrogen bonding in the crystal and this is responsible for the changes in the position and intensity of several bands. The vibrational spectra show that the carboxyl group forms a strong hydrogen bond whereas the nitrogen atoms of the amino and guanidyl groups of the cation form normal hydrogen bonds with the oxygen atoms of the anions. Copyright © 2002 John Wiley & Sons, Ltd.
Analyse vibrationnelle et structurale en série aliphatique saturée. XI—Spectres de vibration de l'acide 3‐méthylglutarique et de ses sels alcalins
Authors: Roger J. , Delarbre J. L. , Maury et L.
Published: January 2003

Raman and infrared spectra of 3‐methylglutaric acid and its sodium salts in aqueous solution (H2O and D2O) were recorded from 4000 to 200 cm−1. The analysis of the polarization of the Raman lines indicated that 3‐methylglutaric acid and its disodium salts belong to the Cs group whereas the acid salt belongs to the C1 group. On the basis of the intermolecular hydrogen bond present in the crystalline state of the acid salts, sodium 3‐methylglutarate can be classified as a type B structure whereas two polymorphic forms (A and B) of the potassium salt were identified. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational spectra of racemic and enantiomeric malic acids
Authors: Barańska H. , Kuduk‐Jaworska J. , Szostak R. , Romaniewska A.
Published: January 2003

The IR and Raman spectra of racemic (DL‐) and both enantiomeric (L‐ and D‐) forms of malic acids and also their silver salts and deuterated analogues were measured in the polycrystalline state in the range 4000–100 cm−1. Significant differences in the spectra of the racemic and enantiomeric forms of malic acid were described for the first time and are discussed in relation to the structural features, including crystal symmetry, geometric parameter distinctions and hydrogen bonding. The most significant spectral differences were noted in the ranges 3000–2800 and 1740–1630 cm−1. In the ν(CH) stretching region distinctions were strongly pronounced in the Raman spectra and the observed pattern was ascribed to crystal symmetry differences. In the second region differences were visible in both the IR and Raman spectra and they were explained as a result of distinctions in the geometric properties of carboxyl‐dimer rings of the L‐ and DL‐forms, namely two non‐equivalent types of H‐bonded carboxyl‐dimer rings are present in the crystal of DL‐form, which results in a doublet in the ν(CO) stretching region. In the case of the enantiomeric form, all H‐bonded carboxyl‐dimer rings are equivalent, so a single ν(CO) band is observed in their spectra. Other differences in the spectra of these species were observed in the region below 1500 cm−1 but their explanation is less straightforward. Copyright © 2002 John Wiley & Sons, Ltd.