Influence of treadmill training on motor performance and organization of exploratory behavior in Meriones unguiculatus with unilateral ischemic stroke: Histological correlates in hippocampal CA1 region and the neostriatum

This study examined the effects of motor stimulation via treadmill on the behavior of male gerbils after external carotid ischemic brain lesion. The animals were assigned to five groups; ischemic with no stimulation (SIG), ischemic with stimulation (SIG 12/24/48/72 It after surgery), non-ischemic with no stimulation (CC), non-ischemic with stimulation (CE) and sham, surgery without occlusion with no stimulation (SH). All the animals were tested in the open-field (OF) and rotarod (RR), 4 days after surgery in order to evaluate exploratory behaviors and motor performance. Data were submitted to one-way variance (ANOVA) and Dunnett`s post hoc comparisons. SIG and SIG 12 groups showed a significant decrease in motor response (crossing) when compared to the control group (CC) (F = 20.65, P < 0.05) in the OF. SIG 12 group showed an increase in grooming behavior (F = 23.136, P < 0.05) and all ischemia groups (SIG, SIG 12/24/48/72) spent less time on the RR (F = 10.40, P < 0.05), when compared to the control group (CC). Histological analyses show extensive lesions in the hippocampus and neostriatum for all groups with ischemia (SIG, SIG 12/24/48/72), which are structures involved in the organization of motor behavior. Interestingly, the most pronounced damage was found in animals submitted to motor stimulation 12 h after ischemia which can be correlated to the increased number of grooming behavior showed by them in the OF. These findings suggest that motor stimulation through treadmill training improve motor behavior after ischemia, except when it starts 12h after surgery. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Upregulation of intermediate calcium-activated potassium channels counterbalance the impaired endothelium-dependent vasodilation in stroke-prone spontaneously hypertensive rats

Endothelial dysfunction has been linked to a decrease in nitric oxide (NO) bioavailability and attenuated endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation. The small (SK(Ca)) and intermediate (IK(Ca)) calcium-activated potassium channels play a key role in endothelium-dependent relaxation. Because the repressor element 1-silencing transcription factor (REST) negatively regulates IK(Ca) expression, we hypothesized that augmented REST and decreased IK(Ca) expression contributes to impaired endothelium-dependent vasodilation associated with hypertension. Acetylcholine (ACh) responses were slightly decreased in small mesenteric arteries from male stroke-prone spontaneously hypertensive rats (SHRSPs) versus arteries from Wistar Kyoto (WKY) rats. Incubation with N-nitro-L-arginine methyl ester (L-NAME; 100 mu mol/L) and indomethacin (100 mu mol/L) greatly impaired ACh responses in vessels from SHRSP. lberiotoxin (0.1 mu mol/L), which is a selective inhibitor of large-conductance K(Ca) (BK(Ca)) channels, did not modify EDHF-mediated vasodilation in SHRSP or WKY. UCL-1684 (0.1 mu mol/L.), which is a selective inhibitor of SKCa channels, almost abolished EDHF-mediated vasodilation in WKY and decreased relaxation in SHRSP. 1-((2-chlorophenyl)diphenylmethyl)-1H-pyrazole (TRAM-34; 10 mu mol/L) and charybdotoxin (0.1 mu mol/L), which are both IKCa inhibitors, produced a small decrease of EDHF relaxation in WKY but completely abrogated EDHF vasodilation in SHRSP. EDHF-mediated relaxant responses were completely abolished in both groups by simultaneous treatment with UCL-1684 and TRAM-34 or charybdotoxin. Relaxation to SK(Ca)/IK(Ca) channels agonist NS-309 was decreased in SHRSP arteries. The expression of SK(Ca) was decreased, whereas IK(Ca) was increased in SHRSP mesenteric arteries. REST expression was reduced in arteries from SHRSP. Vessels incubated with TRAM-34 (10 mu mol/L) for 24h displayed reduced REST expression and demonstrated no differences in IK(Ca). In conclusion, IK(Ca) channel upregulation, via decreased REST, seems to compensate deficient activity of SK(Ca) channels in the vasculature of spontaneously hypertensive rats. (Translational Research 2009; 154:183-193)

Validation of the National Institutes of Health Stroke Scale, Modified Rankin Scale and Barthel Index in Brazil: The Role of Cultural Adaptation and Structured Interviewing

Background: We aimed to validate three widely used scales in stroke research in a multiethnic Brazilian population. Methods: The National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI) were translated, culturally adapted and applied by two independent investigators. The mRS was applied with or without a previously validated structured interview. Interobserver agreement (kappa statistics) and intraclass correlation coefficients were calculated. Results: 84 patients underwent mRS (56 with and 28 without a structured interview), 57 BI and 62 NIHSS scoring. Intraclass correlation coefficient was 0.902 for NIHSS and 0.967 for BI. For BI, interobserver agreement was good (kappa = 0.70). For mRS, the structured interview improved interobserver agreement (kappa = 0.34 without a structured interview; 0.75 with a structured interview). Conclusion: The NIHSS, BI and mRS show good validity when translated and culturally adapted. Using a structured interview for the mRS improves interobserver concordance rates. Copyright (C) 2008 S. Karger AG, Basel

Stroke awareness in Brazil - Alarming results in a community-based study

Background and Purpose-Stroke is the leading cause of death in Brazil. This community-based study assessed lay knowledge about stroke recognition and treatment and risk factors for cerebrovascular diseases and activation of emergency medical services in Brazil. Methods-The study was conducted between July 2004 and December 2005. Subjects were selected from the urban population in transit about public places of 4 major Brazilian cities: S (a) over tildeo Paulo, Salvador, Fortaleza, and Ribeir (a) over tildeo Preto. Trained medical students, residents, and neurologists interviewed subjects using a structured, open-ended questionnaire in Portuguese based on a case presentation of a typical patient with acute stroke at home. Results-Eight hundred fourteen subjects were interviewed during the study period (53.9% women; mean age, 39.2 years; age range, 18 to 80 years). There were 28 different Portuguese terms to name stroke. Twenty-two percent did not recognize any warning signs of stroke. Only 34.6% of subjects answered the correct nationwide emergency telephone number in Brazil (# 192). Only 51.4% of subjects would call emergency medical services for a relative with symptoms of stroke. In a multivariate analysis, individuals with higher education called emergency medical services (P=0.038, OR=1.5, 95%, CI: 1.02 to 2.2) and knew at least one risk factor for stroke (P<0.05, OR=2.0, 95% CI: 1.2 to 3.2) more often than those with lower education. Conclusions-Our study discloses alarming lack of knowledge about activation of emergency medical services and availability of acute stroke treatment in Brazil. These findings have implications for public health initiatives in the treatment of stroke and other cardiovascular emergencies.

Comparisons of the release of vasodilator substances from left and right cardiac chambers of the isolated perfused rabbit heart: Implications for intraventricular thrombus formation

Prostacyclin (PgI(2)) and endothelium-derived nitric oxide (EDNO) are produced by the arterial and venous endothelium. In addition to their vasodilator action on vascular smooth muscle, both act together to inhibit platelet aggregation and promote platelet disaggregation. EDNO also inhibits platelet adhesion to the endothelium. EDNO and PgI(2) have been shown to be released from the cultured endocardial cells. In this study, we examined the release of vasoactive substances from the intact endocardium by using isolated rabbit hearts perfused with physiological salt solution (95% O(2)/5% CO(2), T = 37 degrees C). The right and left cardiac chambers were perfused through separate constant-flow perfusion loops (physiological salt solution, 8 ml min(-1)). Effluent from left and right cardiac, separately, was bioassayed on canine coronary artery smooth muscle, which had been contracted with prostaglandin F(2 alpha_)(2 x 10(-6) M) and no change in tension was exhibit. However, addition of calcium ionophore A23187 (10(-6) M) to the cardiac chambers` perfusion line induced vasodilation of the bioassay coronary ring, 61.4 +/- 7.4% versus 70.49 +/- 6.1% of initial prostaglandin F(2 alpha) contraction for the left and right cardiac chambers perfusate, respectively (mean +/- SEM, n = 10, p > 0.05). Production of vasodilator was blocked totally in the left heart but, only partially blocked in the right heart by adding indomethacin (10(-5) M) to the perfusate, respectively, 95.2 +/- 2.2% versus 41.5 +/- 4.8% (mean +/- SEM, n = 10, p < 0.05). 6-Keto prostaglandin F(1 alpha), measured in the endocardial superfusion effluent was also higher for the left cardiac chambers than for the right at the time of stimulation with the A23187, respectively, 25385.88 +/- 5495 pg/ml (n = 8) versus 13,132.45 +/- 1839.82 pg/ml (n = 8), (p < 0.05). These results showed that cyclooxygenase pathway plays major role in generating vasoactive substances for the left cardiac chamber endocardium; while it is not the main pathway for the right ventricular endocardium at which EDNO and PgI(2) Could act together and potentiate their antithrombogenic activities in isolated perfused rabbit heart. This may be an explanation for the intraventricular thrombus mostly seen in left ventricle rather than in right ventricle as a complication of myocardial infarction. (C) 2009 Elsevier Inc. All rights reserved.

Assessment of two central auditory tests in elderly patients without hearing complaints

Speech understanding disorders in the elderly may be due to peripheral or central auditory dysfunctions. Asymmetry of results in dichotic testing increases with age, and may reflect on a lack of inter-hemisphere transmission and cognitive decline. Aim: To investigate auditory processing of aged people with no hearing complaints. Study design: clinical prospective. Materials and Methods: Twenty-two voluntary individuals, aged between 55 and 75 years, were evaluated. They reported no hearing complaints and had maximal auditory thresholds of 40 dB HL until 4 KHz, 80% of minimal speech recognition scores and peripheral symmetry between the ears. We used two kinds of tests: speech in noise and dichotic alternated dissyllables (SSW). Results were compared between males and females, right and left ears and between age groups. Results: There were no significant differences between genders, in both tests. Their Left ears showed worse results, in the competitive condition of SSW. Individuals aged 65 or older had poorer performances than those aged 55 to 64. Conclusion: Central auditory tests showed worse performance with aging. The employment of a dichotic test in the auditory evaluation setting in the elderly may help in the early identification of degenerative processes, which are common among these patients.

Matrix metalloproteinase 9 gene haplotypes affect left ventricular hypertrophy in hypertensive patients

Background: Matrix metalloproteinases (MMPs) are involved in cardiac remodeling and are encoded by genes showing genetic polymorphisms that have functional implications. We examined whether MMP-9 genetic polymorphisms are associated with hypertension and with left ventricular (LV) remodeling in hypertensive patients. Methods: We studied 173 hypertensive patients and 137 age, race and gender matched healthy controls. Heart echocardiography was performed in all patients and the following MMP-9 genetic polymorphisms were analyzed: C-(1562)T (rs3918242). -90 (CA)(14-24) (rs2234681) and Q279R (rs17576). Haplo.stats analysis was used to assess whether MMP-9 haplotypes are associated with hypertension. Linear regression analysis was performed to assess whether MMP-9 haplotypes affect LV mass index (LVMI) and other echocardiography parameters. Results: MMP-9 90 (CA)14-24 ""HH"" genotype (H allele defined by number of CA repeats >= 21) was associated with hypertension (P = 0.0085; OR = 2.321, 95% confidence interval = 1.250 to 4.309). While one MMP-9 haplotype (""C. H, Q"") protects against LVMI and end-diastolic diameter increases due to remodeling (P = 0.0490 and P = 0.0367), another MMP-9 haplotype apparently has detrimental effects over both parameters in hypertensive patients (""T, H. Q"", P = 0.0015 and P = 0.0057. respectively). Conclusion: Genetic polymorphisms in MMP-9 gene may modify the susceptibility of hypertensive patients to LV remodeling. Further studies are necessary to examine whether these polymorphisms affect clinical events in hypertensive patients. (C) 2010 Elsevier B.V. All rights reserved.

The Stability of the Blood Oxygenation Level-Dependent Functional MRI Response to Motor Tasks Is Altered in Patients With Chronic Ischemic Stroke

Background and Purpose-Functional MRI is a powerful tool to investigate recovery of brain function in patients with stroke. An inherent assumption in functional MRI data analysis is that the blood oxygenation level-dependent (BOLD) signal is stable over the course of the examination. In this study, we evaluated the validity of such assumption in patients with chronic stroke. Methods-Fifteen patients performed a simple motor task with repeated epochs using the paretic and the unaffected hand in separate runs. The corresponding BOLD signal time courses were extracted from the primary and supplementary motor areas of both hemispheres. Statistical maps were obtained by the conventional General Linear Model and by a parametric General Linear Model. Results-Stable BOLD amplitude was observed when the task was executed with the unaffected hand. Conversely, the BOLD signal amplitude in both primary and supplementary motor areas was progressively attenuated in every patient when the task was executed with the paretic hand. The conventional General Linear Model analysis failed to detect brain activation during movement of the paretic hand. However, the proposed parametric General Linear Model corrected the misdetection problem and showed robust activation in both primary and supplementary motor areas. Conclusions-The use of data analysis tools that are built on the premise of a stable BOLD signal may lead to misdetection of functional regions and underestimation of brain activity in patients with stroke. The present data urge the use of caution when relying on the BOLD response as a marker of brain reorganization in patients with stroke. (Stroke. 2010; 41:1921-1926.)

Echocardiographic identification of the oblique vein of the left atrium: its relationship to the persistent left superior caval vein

Thus far, little has been written concerning echocarchographic identification of the oblique of the left atrium, or Marshall`s vein. There is much discussion, nonetheless, on the potential significance of the vein, or its ligamentous remnant, as an arrhythmic substrate. We describe here four patients in whom transthoracic echocardiography revealed a venous structure protruding within the cavity of the left atrium. We discuss the possibility that these structures represent Marshall`s vein, albeit probably as part of a persistent left superior caval vein.

The Developing Left Superior Cervical Ganglion of Pacas (Agouti Paca)

In this study the main question investigated was the number and size of both binucleate and mononucleate superior cervical ganglion (SCG) neurons and, whether post-natal development would affect these parameters. Twenty left SCGs from 20 male pacas were used. Four different ages were investigated, that is newborn (4 days), young (45 days), adult (2 years), and aged animals (7 years). By using design-based stereo-logical methods, that is the Cavalieri principle and a physical disector combined with serial sectioning, the total volume of ganglion and total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal (somal) volume of mononucleate and binucleate neurons was estimated using the vertical nucleator. The main findings of this study were a 154% increase in the SCG volume, a 95% increase in the total number of mononucleate SCG neurons and a 50% increase in the total volume of SCG neurons. In conclusion, apart from neuron number, different adaptive mechanisms may coexist in the autonomic nervous system to guarantee a functional homeostasis during ageing, which is not always associated with neuron losses. Anat Rec, 292:966-975, 2009. (C) 2009 Wiley-Liss, Inc.

Timing and duration of the last interglacial inferred from high resolution U-series chronology of stalagmite growth in Southern Hemisphere

High-precision Th-230-U-238 ages for a stalagmite from Newdegate Cave in southern Tasmania, Australia define a rare record of precipitation between 100 and 155 ka before the present. The fastest stalagmite growth occurred between 129.2 +/- 1.6 and 122.1 +/- 2.0 ka (similar to 61.5 mm/ka), coinciding with a time of prolific coral growth from Western Australia (128-122 ka). This is the first high-resolution continental record in the Southern Hemisphere that can be compared and correlated with the marine record. Such correlation shows that in southern Australia the onset of full interglacial sea level and the initiation of highest precipitation on land were synchronous. The stalagmite growth rate between 129.2 and 142.2 ka (similar to 5.9 mm/ka) was lower than that between 142.2 and 154.5 ka (similar to 18.7 mm/ka), implying drier conditions during the Penultimate Deglaciation, despite rising temperature and sea level. This asymmetrical precipitation pattern is caused by latitudinal movement of subtropical highs and an associated Westerly circulation, in response to a changing Equator-to-Pole temperature gradient. Both marine and continental records in Australia strongly suggest that the insolation maximum between 126 and 128 ka at 65 degreesN was directly responsible for the maintenance of full Last Interglacial conditions, although the triggers that initiated Penultimate Deglaciation (at similar to 142 ka) remain unsolved. (C) 2001 Elsevier Science B.V. All rights reserved.

Conceptualizing quality of life for elderly people with stroke

Purpose : Despite increased interest in quality of life (QOL) as an outcome measure and as a means of identifying client needs in health care, its conceptualisation and the identification of its constituents have been poorly researched for elderly people with stroke in Hong Kong. Method: This article analysed the literature to identify components relevant to the QOL of Chinese elderly people with stroke living in the community in Hong Kong. Results : While common components of QOL for elderly people with and without stroke and regardless of cultural background were identified, a number were specific to an elderly Chinese stroke population. Conclusion : Recommendations for future research have been made with reference to further exploring and validating these components for the target population. A clear understanding of these aspects is essential for the development of sensitive QOL measures to guide and evaluate service delivery to this population.

Manual asymmetries in the preparation and control of goal-directed movements

The primary purpose of this experiment was to determine if left hand reaction time advantages in manual aiming result from a right hemisphere attentional advantage or an early right hemisphere role in movement preparation. Right-handed participants were required to either make rapid goal-directed movements to small targets or simply lift their hand upon target illumination. The amount of advance information about the target for a particular trial was manipulated by precuing a subset of potential targets prior to the reaction time interval. When participants were required to make aiming movements to targets in left space, the left hand enjoyed a reaction advantage that was not present for aiming in right space: or simple finger lifts. This advantage was independent of the amount or type of advance information provided by the precue. This finding supports the movement planning hypothesis. With respect to movement execution, participants completed their aiming movements more quickly when aiming with their right hand, particularly in right space. This right hand advantage in right space was due to the time required to decelerate the movement and to make feedback-based adjustments late in the movement trajectory. (C) 2001 Academic Press.