bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain Monoaminergic Activity in Rainbow Trout Selected for High and Low Stress Responsiveness
Authors: Øverli Øyvind , Pottinger Tom G. , Carrick Toby R. , Øverli Elisabeth , Winberg Svante
Published: April 2003

This paper investigates whether two lines of rainbow trout displaying genetically determined variation in stress responsiveness and behavior also show differences in brain monoaminergic activity. In several brain regions, strains of rainbow trout selected for consistently high or low post-stress cortisol levels displayed differences in tissue concentrations of monoamines and/or monoamine metabolites, or in metabolite/monoamine ratios. High-responsive trout reacted to stress by an increase in the concentrations of both serotonin (brain stem), dopamine (brain stem), and norepinephrine (optic tectum, telencephalon), whereas low-responsive fish did not. Brain stem and optic tectum concentrations of monoamine metabolites were also elevated after stress in high responders, but not in low-responsive fish. The simultaneous increase in the concentration of monoamines and their metabolites suggests that both synthesis and metabolism of these transmitters were elevated after stress in high-responsive trout. A divergent pattern was seen in the hypothalamus, where low-responsive fish displayed elevated levels of 5-hydroxyindoleacetic acid (a serotonin metabolite) and 3-methoxy-4-hydroxyphenylglycol (a norepinephrine metabolite). In the telencephalon, both populations had elevated concentrations of these metabolites after stress. These results clearly suggest that selection for stress responsiveness in rainbow trout is also associated with changes in the function of brain monoaminergic systems. The possible functional significance of these observations is discussed with respect to the physiological and behavioral profile of these strains of fish. Literature is reviewed showing that several factors affecting brain monoaminergic activity might be altered by selection for stress responsiveness, or alternatively be under direct influence of circulating glucocorticoids.
Sciaenid Inner Ears: A Study in Diversity
Authors: Ramcharitar John , Higgs Dennis M. , Popper Arthur N.
Published: April 2003

Sciaenid fishes (Family Sciaenidae) could potentially serve as models for understanding the relationship between structure and function in the teleost auditory system, as they show a broad range of variation in not only the structure of the ear but also in the relationship between the ear and swim bladder. In this study, scanning electron microscopy (SEM) was used to investigate inner ear ultrastructure of the Atlantic croaker (Micropogonias undulatus), spotted seatrout (Cynoscion nebulosus), kingfish (Menticirrhusamericanus) and spot (Leiostomus xanthurus). These species reflect the diversity of otolith and swim bladder morphology in sciaenids. The distribution of different hair cell bundle types, as well as hair cell orientation patterns on the saccular and lagenar maculae of these fishes were similar to one another. The rostral ends of the saccular sensory epithelia (maculae) were highly expanded in a dorsal-ventral direction in the Atlantic croaker and spotted seatrout as compared to the kingfish and spot. Also, ciliary bundles of the saccular maculae contained more stereocilia in the Atlantic croaker and spotted seatrout as compared with kingfish and spot. The shapes of the lagenar maculae were similar in all four species. In the Atlantic croaker and spotted seatrout lagenar maculae, the number of stereocilia per bundle was greater than those for the kingfish and spot. Given that saccular macula shape and numbers of stereocilia per bundle correlate with swim bladder proximity to the ear in the studied species, it is possible that inner ear ultrastructure could be indicative of auditory ability in fishes.
Mechanisms of Development of Heart Failure in the Hypertensive Patient
Authors: Bristow Michael R.
Published: April 2003

Hypertension is a major risk factor for the development of heart failure. Mechanisms which maintain normal function in the short term in the pressure overloaded heart have longer term deleterious effects. These include left ventricular (LV) hypertrophy and chronic activation of the adrenergic and renin-angiotensin systems. β-Blocking agents are capable of blocking the adrenergic system and, to some extent, the renin-angiotensin system. They are therefore attractive in treating hypertension, both for preventing the development of abnormalities and for reversing established LV dysfunction and hypertrophy. Trials in heart failure have shown that these agents prevent progressive myocardial dysfunction, prevent and reverse remodelling and improve intrinsic systolic function. Non-selective β-blocking agents appear to offer greater anti-adrenergic effects than selective ones. However, more research is needed, including direct comparisons of different agents.
Influence of Maternal Xylitol Consumption on Mother–Child Transmission of Mutans Streptococci: 6–Year Follow–Up
Authors: Söderling E. , Isokangas P. , Pienihäkkinen K. , Tenovuo J. , Alanen P.
Published: April 2003

Xylitol is effective as a noncariogenic or even cariostatic sugar substitute. Habitual xylitol consumption appears to select for mutans streptococci (MS) which shed easily into saliva from plaque. We have earlier shown that habitual xylitol consumption of mothers was associated with a statistically significant reduction in the probability of mother–child transmission of MS assessed at 2 years of age. The aim of the present study was to assess the children’s MS counts 1 and 4 years after the maternal xylitol consumption had been discontinued. At baseline, during pregnancy, all mothers (n = 195) showed high salivary levels of MS. The mothers were randomly assigned to xylitol, fluoride (F) and chlorhexidine (CHX) groups. In the xylitol group, the mothers chewed xylitol–sweetened gum, for 21 months, starting 3 months after delivery. In the two control groups, the mothers received CHX or F varnish treatments at 6, 12 and 18 months after delivery. At the 2–year examination, 169 mother–child pairs participated. At the 3–year and 6–year examinations, there were 159 and 147 children in the study, respectively. For children’s MS analyses, visible plaque was collected using toothpicks at the age of 3 and paraffin–stimulated saliva at the age of 6. The persons involved in the collection and analysis of the microbiological samples were blinded as to the study design and group. Both the plaque and salivary MS were cultured on Mitis salivarius agars containing bacitracin. In all groups, the colonization percentages increased during the follow–up. At the 3–year examination, the children’s risk of having MS colonization was 2.3–fold in the F group (95% CI 1.3–4.2) compared to the xylitol group. This difference was statistically significant. Even at 6 years of age, the salivary MS levels were significantly lower in the xylitol group than in the other groups (ANOVA, p<0.001). In conclusion, the earlier demonstrated, xylitol–associated reduction in the probability of mother–child transmission of MS was still found in the children’s MS counts at the age of 3 and 6 years.
Influence of Approximal Caries in Primary Molars on Caries Rate for the Mesial Surface of the First Permanent Molar in Swedish Children from 6 to 12 Years of Age
Authors: Mejàre I. , Stenlund H. , Julihn A. , Larsson I. , Permert L.
Published: April 2003

The objective was to assess the influence on the caries rate for the mesial surface of the first permanent molar (6m) of the caries status of the distal surface of the second primary molar (05d) in children from 6 to 12 years of age. The study design was retrospective and included 374 children with an average of 5 sets of bite–wing radiographs. The mean age of the children was 6.7 years when the first bite–wing radiographs were taken and 11.5 years at the time of the latest radiographs included in the study. The approximal surfaces were classified according to a scoring system: 0 = no visible radiolucency, 1= radiolucency in the outer half of the enamel, 2 = radiolucency in the inner half up to the enamel–dentin border, 3 = radiolucency with a broken enamel–dentin border but with no obvious involvement of the dentin, 4 = radiolucency with obvious spread in the outer half of the dentin, and score 5 = radiolucency in the inner half of the dentin. The influence of the status of 05d on the caries rate for 6m (state ≧2) was assessed by using a model for dependence between the two neighbouring surfaces. Presence or absence of approximal caries in the distal surface of the first primary molars (04d) and/or the mesial surface of the second primary molars (05m) at the time of eruption of 6m was also related to the caries rate for 6m. The caries rate for 6m was 15 times higher if 05d had developed enamel/enamel–dentin border caries (state 2 or 3) compared to a radiographically sound 05d (state 0 or 1). No significant increase in the caries rate for 6m was found when 05d had deeper unrestored dentin caries than when 05d had superficial caries (state 2 or 3). Furthermore, for preventing caries in 6m, no benefit could be found from restoring an 05d with dentin caries with amalgam as opposed to leaving the carious lesion unrestored until exfoliation. The caries rates for 6m and 05d were 3.4 and 2.7 times higher, respectively, in the presence of dentin caries/restoration in 04d/05m compared to absence of dentin caries in these molar surfaces at the time of eruption of 6m. In conclusion, the caries rate for 6m depended on the status of 05d and increased 15 times if 05d had enamel/enamel–dentin border caries compared to a sound 05d. Deeper unrestored or restored dentin lesions in 05d did not result in a higher caries rate for 6m compared with more shallow carious lesions in 05d.
Effect of a Low–Fluoride–Content, Two–Component Rinse on Fluoride Uptake and on De– and Remineralization of Enamel Lesions: An in vitro Study
Authors: Takagi S. , Liao H. , Chow L.C.
Published: April 2003

The effect of calcium (Ca) concentrations and added ethanol on fluoride (F) depositions by experimental two–component rinses, each consisting of a Ca–containing and an F–containing component, was evaluated in an in vitro system. Among the tested rinses, a 3 mmol/l F two–component rinse with 200 mmol/l Ca and 10% v/v ethanol was found to produce the greatest F deposition relative to the F concentration in the rinse. Specifically, this rinse produced an F deposition that was about 7 times greater than a conventional 13.2–mmol/l sodium fluoride (NaF) rinse. In a second experiment, an in vitro pH cycling model was used to evaluate the potential anti–caries effects of 4 rinses: (1) placebo rinse (no F), (2) 13.2–mmol/l NaF rinse, (3) 52.6–mmol/l NaF rinse, and (4) the 3–mmol/l F two–component rinse in a 7–day in vitro pH cycling model. The changes in lesion mineral contents, delta(ΔZ), as assessed by quantitative microradiographic measurements, were as follows [mean ± standard deviation, n = 10]: (1) 72.5±10.2 µm, (2) 43.4±5.6 µm, (3) 17.3±10.2 µm and (4) 45.3±5.2 µm. These results showed that the 3–mmol/l F two–component rinse produced the same (p>0.05) protection against demineralization as did the 13.2–mmol/l NaF rinse which had 4 times the fluoride content. The results suggest that it is possible to formulate an effective low–F two–component rinse.
Effectiveness of Two Fluoridation Measures on Erosion Progression in Human Enamel and Dentine in vitro
Authors: Ganss C. , Klimek J. , Schäffer U. , Spall T.
Published: April 2003

The aim of the present study was to evaluate the effect of fluoride on the progression of erosive demineralisation in human enamel and dentine using a cyclic de– and remineralisation model in vitro. The mineral content expressed in micrometres was determined daily by longitudinal microradiography (LMR) and presented as cumulative mineral loss over 5 days. For erosive demineralisation, all samples were immersed in 0.05 M citric acid (pH 2.3) for 6×10 min/day and stored in a remineralisation solution. Fluoridation measures were performed as follows: group 1: control, no fluoridation; group 2: toothpaste fluoridation 3×5 min/daily (NaF, 0.15% F–); group 3: toothpaste fluoridation as group 2 and additionally application of a fluoride mouthrinse (Olaflur/SnF2, 0.025%F–) 3×5 min/daily and on days 1 and 3 gel fluoridation (Olaflur/NaF; 1.25% F–) for 1×5 min. After the first experimental day, no significant differences were found between the groups. However, after 5 days the erosive mineral loss values for enamel were 147.5±18.7 µm in the control group, 128.1±15.0 µm in group 2 (p≤0.05) and 116.1±12.4 µm in group 3 (p≤0.001). In dentine, the respective values were 136.7±16.4, 111.8±26.9 (p≤0.001) and 60.3±17.8 (p≤0.001). The intensive fluoridation significantly reduced erosion progression in enamel but had a more pronounced effect on dentine. The results suggest that subjects with erosive lesions should use an intensive fluoridation measure.
The Effects of Benzoate and Fluoride on Dental Caries in Intact and Desalivated Rats
Authors: Davis B.A. , Raubertas R.F. , Pearson S.K. , Bowen W.H.
Published: April 2003

The decline in prevalence of dental caries in some segments of the population has been attributed mainly to extensive exposure to fluoride. Over the past decades, the use of fluoridated products has increased. During the same period, the consumption of food preservatives such as benzoates and sorbates has also increased substantially. Benzoates, in vitro, possess antibacterial properties similar to those of fluoride and in combination with fluoride could affect caries development. In the present study we explored the effects of sodium benzoate and fluoride in combination and alone on dental caries in our animal model. The results showed a combination of benzoate and fluoride reduced caries activity more effectively in rodents fed a cariogenic diet ad libitum than fluoride alone (p = 0.038).
Twenty–Four Month Incidence of Root Caries among a Diverse Group of Adults
Authors: Gilbert G.H. , Duncan R.P. , Dolan T.A. , Foerster U.
Published: April 2003

Objectives: (1) Describe for a diverse sample the 24–month incidence of root caries, and (2) test its association with a broad range of clinical, behavioral, financial, and sociodemographic factors. Methods: The Florida Dental Care Study was a cohort study of randomly selected subjects who had at least 1 tooth and were 45 years or older at baseline. In–person interviews and clinical examinations were conducted at baseline and 24 months, with 6–monthly telephone interviews between those times; 723 subjects participated for both examinations. A multinomial logistic regression was done to predict whether the subject was in one of four mutually exclusive groups [new root decay only (NDO); new root filling(s) only (NFO); both new decay and new filling(s) (BOTH), or had neither (NONE)]. Results: Thirty–six percent of subjects had at least 1 new root decayed and/or filled surface (DFS); 17% were in the NDO group, 14% in the NFO group, and 5% in the BOTH group. When limited to participants who had a nonzero increment, the mean (SD) DFS was 2.7 (2.9). Baseline clinical condition (presence of root decay, root filling(s), coronal decay, noncarious root defects, number of teeth present, percent of teeth with at least 4 mm of attachment loss) was predictive of moving from the NONE group into the NDO, NFO, or BOTH groups. The addition of behavioral, financial, and sociodemographic factors improved model fit. For example, regular dental attenders were significantly more likely to move from the NONE group into the NFO group, but regular attendance was not associated with a lower probability of moving from the NONE group into the NDO or BOTH groups. Conclusions: Root caries is a substantive dental health problem in this diverse sample of adults. These analyses demonstrate the utility of disaggregating caries incidence into four mutually exclusive groups for predictive models.
Ancrod in the Treatment of Acute Ischemic Stroke
Authors: Atkinson Richard P.
Published: April 2003

Although ancrod has been used in Europe and Canada since 1968 for various conditions including heparin-induced thrombocytopenia [1], peripheral vascular disease [2] and deep-vein thrombosis [3], its first described use for stroke patients was in 1983 [4]. Since then one large double-blind placebo-controlled randomized study treating acute stroke patients within 6 h has been completed and published [5]. Another larger study, treating patients within 3 h of stroke onset, is nearing completion in 1997.
New Concepts for Drug Therapy after Stroke
Authors: Wahlgren Nils Gunnar , Martinsson Louise
Published: April 2003

Neurologic functions improve in most patients days and weeks after onset of a stroke. This can not be explained by recovery of the early salvageable ischemia zone. The most likely mechanism is relearning, a process in which healthy brain takes over functions lost with the infarct. Experimental studies indicate that this recovery can be modulated by pharmacological agents. NMDA antagonists and GABA agonists found to reduce infarct size in stroke models may have a harmful effect on relearning and neurologic recovery. This should be considered when clinical trial protocols are designed.
Evaluation of the Secretory Pattern of Plasma Arginine Vasopressin in Stroke Patients
Authors: Barreca T. , Gandolfo C. , Corsini G. , Del Sette M. , Cataldi A. , Rolandi E. , Franceschini R.
Published: April 2003

Arginine vasopressin (AVP) may play a role in the development of ischemic brain edema and/or cerebral vasospasm. Data available on AVP plasma levels in ischemic stroke are few and discordant. In order to ascertain whether changes in AVP plasma levels occur in ischemic stroke, plasma AVP levels, plasma osmolality and mean arterial pressure were determined in 24 patients with unprecedented ischemic cerebral infarction and in 15 controls over a 24-hour period. In stroke patients, mean 24-hour plasma AVP levels (7.2 ± 0.8 ng/l) were higher (p < 0.05) than in control subjects (2.4 ± 0.3 ng/l), and correlated with the severity score of the neurologic deficit and the mean size of the lesion. In patients with a more severe neurologic deficit, the mean 24-hour plasma AVP levels (8.7 ± 1.0 ng/l) were higher than in patients with a less severe neurologic deficit (5.2 ± 0.8 ng/l). Data indicate that in ischemic stroke an increased AVP secretion occurs independently of osmotic or baroreceptorial mechanisms. The possibility that AVP may play a role in neuronal cell damage following cerebral ischemia warrants further attention.
Diffusion-Weighted MR in Cerebral Venous Thrombosis
Authors: Lövblad Karl-Olof , Bassetti Claudio , Schneider Jacques , Guzman Raphael , El-Koussy Marwan , Remonda Luca , Schroth Gerhard
Published: April 2003

The diagnosis of cerebral venous thrombosis is often difficult both clinically and radiologically and until now there is no method available to predict if brain lesions, detected clinically and using conventional brain imaging methods, may lead to full recovery, as expected in vasogenic edema or ischemic infarcts and even a hematoma. New fast neuroimaging techniques such as diffusion-weighted imaging (DWI) are sensitive to different reasons of changes in local tissular water concentration thus giving further insight into the pathophysiological mechanism as well as prognosis of cerebral venous thrombosis. We report the cases of 18 consecutive patients with a diagnosis of cerebral venous thrombosis based on clinical and imaging criteria. All patients underwent magnetic resonance imaging (MRI) of the brain, which comprised isotropic diffusion-weighted MR. Diffusion-weighted MRI showed positive findings in 17/18 cases. In 7 cases the clot could be directly visualized as an area of hyperintensity in the affected vein on DWI. In 7 cases DWI showed areas of signal loss corresponding to hematomas. In 6 cases DWI showed changes in signal intensity that were more subtle. In 4 cases of superficial venous thrombosis, there were areas of decreased ADC values (0.65–0.79 × 10–3 mm2/s) whereas in 2 cases of deep venous thrombosis, increased DWI intensities could be found that corresponded to both an increase and a decrease in ADC, corresponding to a coexistence of cytotoxic and vasogenic edemas. Diffusion-weighted MRI can demonstrate directly the presence of an intravenous clot in a select number of patients. It can also demonstrate early ischemic changes, and can differentiate conventional T2-weighted MR areas of cytotoxic from vasogenic edema.
Longitudinal Study of Blood Pressure and Stroke in over 37,000 People in China
Authors: Fang Xiang-Hua , Longstreth Jr W.T. , Li Shi-Chuo , Kronmal Richard A. , Cheng Xue-Ming , Wang Wen-Zhi , Wu Shengping , Du Xiao-Li , Dai Xiu-Ying
Published: April 2003

As part of a longitudinal study performed in urban China, 37,655 subjects were evaluated for stroke risk factors, including having their blood pressure measured in a standard fashion. The cohort was followed for 3.5 years during which time 427 subjects experienced incident strokes – 221 ischemic, 203 hemorrhagic, and 3 undefined. Both systolic and diastolic blood pressure were significantly related to risk of stroke and stroke type. Associations were stronger for systolic than diastolic blood pressure. These results emphasize the importance of systolic blood pressure, as opposed to diastolic, as a risk factor for stroke. In this study, the risk of stroke is increased by about 25% with each 10 mm Hg increase in systolic blood pressure.
Blood Pressure Variability in Binswanger’s Disease and Isolated Lacunar Infarction
Authors: Martí-Fàbregas Joan , Valencia Carlos , López-Contreras Joaquín , Roca-Cusachs Alex , Solé María José , García-Sánchez Carmen , Martí-Vilalta Josep-Lluis
Published: April 2003

To determine whether blood pressure (BP) variability is increased in hypertensive patients with Binswanger’s disease (BD), we studied two samples of consecutive treated hypertensive patients: (1) 11 with BD (mean age 71.3 ± 5.2 years); (2) 16 with lacunar infarction (mean age 65.2 ± 8.3 years) without cognitive impairment. An averaged baseline office BP was obtained for 3 consecutive weeks. Ambulatory BP monitoring was then carried out to obtain the averaged mean systolic (SBP) and diastolic BP, and BP variability was defined as the standard deviation of consecutive BP values. Results: Diurnal SBP variability was significantly increased in the BD group (p = 0.04). However, with the analysis of covariance for age and baseline office BP, the difference was no longer significant (p = 0.17 and p = 0.09, respectively). We conclude that increased BP variability in BD patients is probably due to older age and increased baseline office BP. Increased BP variability may be a risk factor for small-vessel disease, but not for cognitive impairment.
Acetylsalicylic Acid and Microembolic Events Detected by Transcranial Doppler in Symptomatic Arterial Stenoses
Authors: Goertler Michael , Blaser Till , Krueger Stephan , Lutze Gerd , Wallesch Claus-Werner
Published: April 2003

Background: In patients with symptomatic carotid artery stenosis, high-intensity transient signals detected by transcranial Doppler (TCD) have been related to particulate microemboli originating at the stenotic lesion. The occurrence of these microembolic events within the Doppler spectrum should be influenced by antithrombotic agents of proven efficacy in these patients mainly by reducing cerebral embolism. Methods: Seventy-four of 192 consecutive patients with symptomatic arterial stenosis in the anterior circulation and clinical symptoms within the last 30 days underwent 1-hour bilateral TCD monitoring. Patients were selected, if they presented temporal bone windows enabling transcranial insonation, revealed normal Doppler CO2 test excluding hemodynamic impairment, had not received antithrombotic therapy other than acetylsalicylic acid (ASA) before sonographic examination, and gave informed consent to 1-hour monitoring which could be performed immediately on admission/presentation of the patient at the Department of Neurology. Results: Microembolic events were detected in 38 patients (51%). The proportion of patients with events among 26 patients without antithrombotic medication was 73% as compared with 40% in 48 patients receiving ASA at the time of TCD monitoring (p = 0.023). Multivariate analysis including time from ischemia to TCD, presence and start of ASA prevention, degree and localization of stenosis, and presence of a single or recurrent ischemia revealed that absence of an ASA prevention (odds ratio OR 7.1, 95% confidence interval CI 1.6–31.4, p = 0.010), recurrent ischemic events (OR 7.1, 95% CI 1.6–32.7, p = 0.011), and extracranial localization of the stenosis (OR 3.8, 95% CI 1.1–13.2, p = 0.038) were independent predictors for microembolic events. Conclusion: In patients with symptomatic arterial stenosis, the absence of an ASA medication is associated with the occurrence of TCD-detected microembolic events, suggesting a relation between these events and ASA-sensitive microemboli from the stenotic lesion.
Circadian Variation of Stroke Onset in Hong Kong Chinese: A Hospital-Based Study
Authors: Cheung Raymond T.F. , Mak Windsor , Chan K.H.
Published: April 2003

Circadian variation of onset of transient ischaemic attack (TIA) or stroke during four 6-hourly periods starting from midnight was studied in Hong Kong Chinese patients admitted to a regional hospital between October 1996 and July 1999. The onset was classifiable into one of the 6-hourly periods in 832 of 905 patients; patients with unclassifiable onset were more likely to have lacunar infarct and less likely to have intracerebral haemorrhage (ICH). There was a significant circadian variation of onset in all strokes and TIA, TIA alone, ischaemic stroke (IS), ICH and different IS subtypes. The risk of onset was greatest between 6 a.m. and noon for IS or TIA, but between noon and 6 p.m. for ICH. There was no difference in the circadian variation between patients with and without prior TIA or stroke. This hospital-based study revealed a significant circadian variation of onset in different types and subtypes of stroke.
Vascular Dementia: A Cognitive SPET-CBF Activation Study
Authors: Di Piero V. , Giannini M. , Bragoni M. , Vicenzini E. , Di Legge S. , Altieri M. , Pantano P. , Lenzi G.L.
Published: April 2003

Objective: We investigated the pattern of regional cerebral blood flow (rCBF) responses to a cognitive task in vascular patients with and without dementia. Method: We studied 8 controls and 18 vascular patients by quantitative rCBF assessed by 133Xe inhalation method and SPET, both at rest and during a cognitive figure recognition task. Eight were mildly demented and 10 were nondemented vascular patients. According to their task performance, 12 patients were classified as ‘good performers’ (GPs) and 6 patients as ‘poor performers’ (PPs). Results: Vascular patients activated a larger number of brain areas than controls. No differences were observed between controls, nondemented and mildly demented patients in the pattern of rCBF activation. GPs presented a lower mean percentage of rCBF increase than either controls or PPs. GPs had lower values than PPs in the left temporal, parietal and occipital regions and in the right posterior cingulate and occipital regions. Conclusions: These data suggest that vascular patients may functionally compensate for vascular damage by activating more brain areas than controls do and, consequently, by increasing the rate of regional activation.
Clinically Silent Circulating Microemboli in 20 Patients with Carotid or Vertebral Artery Dissection
Authors: Droste Dirk W. , Junker Katja , Stögbauer Florian , Lowens Stefan , Besselmann Michael , Braun Bertram , Ringelstein E. Bernd
Published: April 2003

Background and Purpose: Carotid and vertebral artery dissections are frequently complicated by cerebral embolism. Detection of clinically silent circulating microemboli by transcranial Doppler sonography (TCD) is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke. Methods: In 20 patients with carotid (n = 17) or vertebral (n = 2) artery dissection, or both (n = 1), we performed a 1-hour microembolus detection downstream to the dissection in the middle or in the posterior cerebral artery, respectively. Results: Five patients with a carotid artery stenosis of ≧90% or with carotid artery occlusion showed microembolic signals at a rate of up to 15 events/h. In all these patients, the onset of the dissection was within the last 58 days. Patients with lower degrees of stenosis or onset of symptoms beyond 58 days did not show microembolic signals at all. Three patients who had presented with recurrent ischaemic events prior to TCD monitoring unexceptionally had microembolic signals. Conclusion: Microembolic signals occur in patients with high-grade stenosis or occlusion due to acute cervical artery dissection. Patients with microemboli seem to be at increased macroembolic risk, i.e. stroke recurrence, and may require close-meshed clinical follow-up and possibly stronger antithrombotic treatment.
Correlation between Diffusion- and Perfusion-Weighted MRI and Neurological Deficit Measured by the Scandinavian Stroke Scale and Barthel Index in Hyperacute Subcortical Stroke (≤6 Hours)
Authors: Røhl L. , Geday J. , Østergaard L. , Simonsen C.Z. , Vestergaard-Poulsen P. , Andersen G. , Le Bihan D. , Gyldensted C.
Published: April 2003

Objective: We used combined diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI to characterize hyperacute infarctions within 6 h of symptom onset with special reference to subcortical infarctions, and investigated the relation between perfusion-diffusion mismatch volume and functional outcome. Material and Methods: Twenty-two patients presenting with symptoms of acute stroke underwent DWI and PWI within 6 h of symptom onset, and follow-up MRI 30 days later. Twelve of these had a subcortical infarction on acute DWI. Lesion volumes were measured by acute DWI and PWI as well as chronic T2-weighted MRI (T2WI). Clinical severity was measured by the Scandinavian Stroke Scale (SSS) and the Barthel Index (BI). Results: In the 12 patients with subcortical infarctions, PWI and especially DWI correlated strongly with acute and chronic neurological SSS score, as well as with final infarct volume. Furthermore, a hyperacute PWI/DWI mismatch in this subgroup predicted lesion growth. There was a weaker correlation between acute DWI/PWI and neurological score among all 22 patients, and patients with a PWI/DWI mismatch larger than 100 ml had a significantly larger lesion growth and a poorer outcome than patients with a smaller mismatch. Conclusions: Subcortical infarctions may represent a sizeable subgroup of acute stroke patients. Also subcortical infarctions may have a PWI/DWI mismatch and therefore may respond to neuroprotective/thrombolytic therapy. Hyperacute DWI may reflect the acute clinical status and predict the outcome in patients with subcortical infarction.
Outcome in Patients with Symptomatic Occlusion of the Internal Carotid Artery or Intracranial Arterial Lesions: A Meta-Analysis of the Role of Baseline Characteristics and Type of Antithrombotic Treatment
Authors: Klijn Catharina J.M. , Kappelle L. Jaap , Algra Ale , van Gijn Jan
Published: April 2003

Objectives: We performed a systematic review of the literature to assess the impact of potential risk factors of recurrent stroke other than a compromised cerebral blood flow in patients with carotid occlusion or intracranial arterial lesions. In addition, we investigated the effect of treatment with aspirin or oral anticoagulation on recurrent stroke rate and assessed whether the incidence of recurrent stroke has decreased over the years. Methods: We searched Medline (1966 and onwards) and reference lists of identified articles for papers reporting on the recurrent stroke risk in patients with carotid occlusion or intracranial arterial lesions. Two authors independently extracted information from all papers. The influence of study characteristics on the risk of the endpoints ‘recurrent stroke’, ‘ipsilateral stroke’ and ‘vascular death’ was determined by Poisson regression analysis. Rate ratios were calculated per 10 percentage points increase of a characteristic. Results and Conclusions: Patients with intracranial carotid stenosis or occlusion had a higher rate of recurrent stroke (rate ratio 1.09; 95% CI 1.05–1.14) than patients with extracranial carotid occlusion or middle cerebral artery stenosis or occlusion. In patients with bilateral carotid occlusion the rate was lower (rate ratio 0.82; 95% CI 0.68–0.98). No other vascular risk factors than hypertension (rate ratio 1.23; 95% CI 1.07–1.41) could be shown to increase the rate of recurrent stroke. Oral anticoagulation but not aspirin had a protective effect on the incidence of recurrent stroke (rate ratio 0.86; 95% CI 0.79–0.93). The reported rates of recurrent stroke in patients with symptomatic occlusion of the internal carotid artery or intracranial arterial lesions have not decreased over the years.
Elevated Levels of Anti-Heat Shock Protein Antibodies in Patients with Cerebral Ischemia
Authors: Gromadzka Grażyna , Zielińska Justyna , Ryglewicz Danuta , Fiszer Urszula , Członkowska Anna
Published: April 2003

One of the important mechanisms involved in the development of vascular lesions leading to ischemic stroke could be an immune response to heat shock proteins (hsp). For carotid atherosclerosis and myocardial infarction, an association with an increase in anti-hsp 65 antibodies has been demonstrated. The aim of our study was (1) to investigate whether ischemic stroke is associated with a humoral immune response to hsp; (2) to study the connection between anti-hsp antibodies and other stroke risk factors; (3) to estimate if the elevated levels of anti-hsp antibodies could be an independent risk factor for stroke. We examined 180 patients (in the first 48 h after stroke onset) and 64 age-matched healthy controls. The levels of IgG and IgM antibodies to hsp 65 and 70 were measured by ELISA. Ischemic stroke was connected with a significant elevation of anti-hsp 65 and anti-hsp 70 antibody levels (IgG and IgM) compared with controls (p < 0.0001). The multifactorial logistic regression analysis showed that increased levels of anti-hsp 65 and anti-hsp 70 IgG antibodies are independent risk factors for stroke. Our results suggest that humoral immunity to hsp is common in stroke patients and that elevated levels of anti-hsp antibodies could be triggering factors for stroke.
Neurometabolic Changes during Treatment with Moderate Hypothermia in a Patient Suffering from Severe Middle Cerebral Artery Infarction
Authors: Schäbitz W.R. , Berger C. , Schellinger P.D. , Aschoff A. , Steiner T. , Schwab S.
Published: April 2003

Microdialysis is a means of measuring neurochemical changes in the extracellular space and has been applied in acute brain trauma, subarachnoid hemorrhage and stroke patients. In this study, we monitored neurochemical changes in the extracellular space using microdialysis in a patient with left-sided hemispheric infarction treated with moderate hypothermia (33°C). Microdialysis probes were obtained from the infarcted and noninfarcted hemisphere during hypothermia and rewarming. Concentrations of extracellular substances in the infarcted hemisphere (glutamate, glycerine, lactate/pyruvate) decreased with hypothermia and remained stable (glutamate) or increased (glycerine, lactate/pyruvate) during rewarming. Concentrations of these substances in the noninfarcted hemisphere remained at normal levels. Microdialysis monitoring of therapeutic hypothermia in severe hemispheric infarction might be a useful additional monitoring tool to assess the status of the brain and to predict further deterioration.
Should One Use Echocardiography or Contrast Transcranial Doppler Ultrasound for the Detection of a Patent Foramen Ovale after an Ischemic Cerebrovascular Accident?
Authors: Baguet Jean-Philippe , Besson Gérard , Tremel Frédéric , Mangin Lionel , Richardot Christelle , Mallion Jean-Michel
Published: April 2003

Patent foramen ovale is frequently associated with embolic cerebrovascular accidents. The diagnosis of patent foramen ovale is easier since the advent of transesophageal echocardiography. However, this method is semi-invasive and is not readily available in all units. Contrast transcranial Doppler ultrasound enables the detection of the passage of a contrast material injected into a peripheral vein to the cerebral circulation across an orifice which is most often a patent foramen ovale. Contrast transcranial Doppler ultrasound may facilitate, with a high sensitivity and specificity, the diagnosis of a patent foramen ovale when a transesophageal echo is not possible. However, transesophageal echocardiography remains the preferred test especially in the young since other potentially embolic sources, such as a thrombus in the left atrium, may be demonstrable.
Lacunar Stroke: Transoesophageal Echocardiographic Factors Influencing Long-Term Prognosis
Authors: Kazui S. , Levi C.R. , Jones E.F. , Quang L. , Calafiore P. , Donnan G.A.
Published: April 2003

Objective: Since little is known concerning factors which may influence long-term prognosis of patients presenting with lacunar stroke, we conducted a longitudinal study of this stroke subtype. Variables likely to affect outcome were assessed at baseline, including those from transoesophageal echocardiographic studies. Methods: Consecutive patients presenting with first-ever lacunar stroke underwent diagnostic workup that included brain CT or MRI, carotid duplex, and transthoracic and transoesophageal echocardiography. An assessment of patients was planned at entry (baseline), and thereafter every 12 months (clinic visit or telephone call), drop-out, or endpoint. The primary endpoint was nonfatal or fatal stroke. Secondary endpoint was death due to any cause. Results: Among 60 consecutive lacunar patients with the mean follow-up period of 3.9 years, 12 patients (20%) had stroke recurrence. The mean annual rate for stroke was 5.2%, and for death 2.8%. For multivariate Cox proportional hazards analysis, the following three variables with the values of p < 0.1 after univariate testing were chosen: age (p = 0.095); aortic atheroma (p = 0.066); and any source of embolism from heart (p = 0.007). Any source of embolism from heart was the only factor which significantly enhanced the risk of stroke recurrence (p = 0.015). Using Kaplan-Meier life table analysis, the curves of percent free of recurrent stroke were significantly different (log rank test p = 0.002). Conclusions: Until the mechanism of lacunar stroke is better understood, it is reasonable to suggest that its investigation and prevention should be directed at all potential causes of future strokes including cardioembolism.
Circulating Microemboli in 33 Patients with Intracranial Arterial Stenosis
Authors: Droste Dirk W. , Junker Katja , Hansberg Tjark , Dittrich Ralf , Ritter Martin , Ringelstein E. Bernd
Published: April 2003

Background: Intracranial arterial stenosis is a rare cause of stroke in Caucasians. Detection of clinically silent circulating microemboli by transcranial Doppler sonography is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke. Methods: In 33 patients with intracranial internal carotid (n = 12), middle cerebral (n = 18), posterior cerebral (n = 2), or basilar artery stenosis (n = 1), we performed a 1-hour microembolus detection downstream to the stenosis in the middle or in the posterior cerebral artery, respectively. The stenosis was assessed by transcranial Doppler and duplex ultrasound. 18 patients had been symptomatic in the dependent territory. Results: Five patients with ischaemic symptoms within the last 8 days and with a peak systolic flow velocity of ≧210 cm/s in the stenosis showed microembolic signals at a rate of 3–25 events/h, despite effective anticoagulation. All these 5 patients had a lesion pattern on cranial CT or MRI scan suggesting embolic origin. All the asymptomatic patients (n = 15) and all the patients with a peak systolic intrastenostic velocity of 160 to <210 cm/s (n = 13) did not show microembolic signals at all. Conclusion: Microembolic signals occur in recently symptomatic patients with high-grade intracranial arterial stenosis indicated by a sonographically measured stenotic peak flow velocity of ≧210 cm/s. Therapeutic anticoagulation was not sufficient to suppress microemboli formation.
Poststroke Emotional Incontinence and Decreased Sexual Activity
Authors: Choi-Kwon Smi , Kim Jong S.
Published: April 2003

Background: Although poststroke depression has been shown to be related to decreased sexual activity (SA), the relationship between poststroke emotional incontinence (EI) and SA has not been properly investigated. Methods: We examined 70 nondepressed, sexually active patients with first-ever stroke approximately 3 months after stroke and conducted a follow-up interview approximately 2 years after stroke in 55 of them. EI (excessive/inappropriate laughing/crying) and SA (libido, coital frequency, erectile function) were assessed with the use of a standardized questionnaire. Results: Of these 70 patients, 24 (34%) had EI 3 months after stroke, which had resolved 2 years after stroke. Libido, coital frequency and erectile function were reported to have declined in 49, 65 and 26% of the patients, respectively, 3 months after stroke, and in 44, 49 and 20% of the patients 2 years after stroke. Multivariate analyses showed that low coital frequency before stroke (CFBS) was significantly (p < 0.05) related to decreased poststroke coital frequency, while the presence of EI (p < 0.05) and low CFBS (p < 0.05) was significantly associated with decreased erectile function 3 months after stroke. Two years after stroke, the presence of EI 3 months after stroke was significantly related to decreased libido, coital frequency and erectile function (p < 0.05 each). Age, gender, laterality of stroke, Barthel Index score, motor dysfunction and the presence of hypertension and diabetes mellitus were not independently related to SA 3 months and 2 years after stroke. Conclusion: The presence of EI is a factor related to decreased poststroke SA, more so in chronic than in subacute stages.
Elevated C-Reactive Protein Is Associated with an Increased Intima to Media Thickness of the Common Carotid Artery
Authors: Winbeck Kerstin , Kukla Christian , Poppert Holger , Klingelhöfer Jürgen , Conrad Bastian , Sander Dirk
Published: April 2003

In this study, we analyzed the relationship between serum C-reactive protein (CRP) and the intima to media thickness (IMT) of the common carotid artery in 411 consecutive neurological inpatients (215 males, mean age 64.1 years). The CRP concentration was determined within 12 h and patients were subdivided according to the CRP level. Patients with an elevated CRP (n = 149) showed a significantly larger IMT [1.05 mm (95% confidence interval (CI) 1.02–1.09) vs. 0.92 mm (95% CI 0.89–0.94)]. Multivariate linear regression analysis revealed that an elevated CRP level, age, pack-years of smoking, body mass index, incidence of diabetes mellitus and ischemic stroke were independently associated with an increased IMT (p < 0.05).
Patent Foramen Ovale, a Possible Cause of Symptomatic Migraine: A Study of 74 Patients with Acute Ischemic Stroke
Authors: Sztajzel R. , Genoud D. , Roth S. , Mermillod B. , Le Floch-Rohr J.
Published: April 2003

Recent studies reported an increased prevalence of patent foramen ovale (PFO) in patients with migraine with aura (MA+). To investigate the possible relationship between MA+ and paradoxical embolism, we studied the prevalence of both conditions. Investigation of PFO was undertaken in 74 consecutive patients presenting with an acute stroke of undetermined origin. The patients were questioned about MA+ or migraine without aura (MA–) according to the criteria of the International Headache Society. Follow-up was performed to investigate the evolution of MA+ and MA– according to different treatments of stroke. PFO was found in 44 of 74 patients, 16 of whom had MA+ (36%), compared to 4 (13%) MA+ patients without PFO (p = 0.03). Of 25 patients in whom the PFO was considered to play a causal role in the stroke, 13 (52%) had MA+, whereas only 3 (16%) of 19 patients in whom PFO was considered unrelated had MA+ (p = 0.014). Thirty-nine of the patients with MA+ and MA– were studied over a mean follow-up of 13 months. Seven of 15 patients with MA+ and PFO, treated either with surgical closure or anticoagulants, noticed complete disappearance of MA+ attacks. The prevalence of MA+ is high among stroke patients with PFO. In patients with a high presumption of paradoxical embolism, the proportion of MA+ is increased, and this suggests a possible role of this association in the occurrence of the cerebrovascular event. Forty-seven percent of patients with PFO and MA+ reported complete suppression of their aura attacks after surgical closure or anticoagulant treatment. This finding suggests that at least in some patients, MA+ attacks may be due to paradoxical embolism.
Pericytes: Cell Biology and Pathology
Authors: Allt G. , Lawrenson J.G.
Published: April 2003

Pericytes are perivascular cells with multifunctional activities which are now being elucidated. The functional interaction of pericytes with endothelial cells (EC) is now being established, using current molecular and cytochemical techniques. The detailed morphology of the pericyte has been well described. Pericytes extend long cytoplasmic processes over the surface of the EC, the two cells making interdigitating contacts. At points of contact, communicating gap junctions, tight junctions and adhesion plaques are present. Pericytes appear to show both structural and functional heterogeneity. The coverage of EC by pericytes varies considerably between different microvessel types and the location of pericytes on the microvessel is not random but appears to be functionally determined. Interaction between pericytes and EC is important for the maturation, remodelling and maintenance of the vascular system via the secretion of growth factors or modulation of the extracellular matrix. There is also evidence that pericytes are involved in the transport across the blood-brain barrier and the regulation of vascular permeability. The long-standing view that pericytes are the microvessel equivalent of larger vessel smooth muscle cells and are contractile is being reassessed using current methods. An important role for pericytes in pathology, and neuropathology in particular, has been indicated in hypertension, diabetic retinopathy, Alzheimer’s disease, multiple sclerosis and CNS tumour formation.
MRI Morphometric Study and Correlation with Cognitive Functions in Young Adults Shunted for Congenital Hydrocephalus Related to Spina bifida
Authors: Hommet C. , Cottier J.P. , Billard C. , Perrier D. , Gillet P. , De Toffol B. , Sirinelli D. , Bertrand P. , Autret A.
Published: April 2003

We studied the morphometric MRI findings and their correlation with cognitive functions in a population of 10 young adults shunted for congenital hydrocephalus related to spina bifida. Morphometric MRI analysis included measurement of the ventricular dilatation index, frontal and occipital parenchymal thickness and the size of the corpus callosum. The neuropsychological status was evaluated, notably to look for a discrepancy between verbal and performance skills, a finding which has previously been described in hydrocephalic children. We also investigated whether there was a correlation between cognitive function and cerebral morphometric indexes. In each case, MRI demonstrated the structural changes associated with the Chiari II malformation. The size of the lateral ventricles varied, ranging from important dilatation to small ventricles. Six patients had only partial development of the corpus callosum. All patients had a normal global IQ. In our population of young adults, we did not observe any discrepancy between verbal and visuospatial performances as has been described in children with hydrocephalus. We found no relationship between cognitive function and ventricle dilatation or parenchymal thickness or between the size of the corpus callosum and callosal transfer.