Taekwondo training improves balance in volunteers over 40.

Balance deteriorates with age, and may eventually lead to falling accidents which may threaten independent living. As Taekwondo contains various highly dynamic movement patterns, Taekwondo practice may sustain or improve balance. Therefore, in 24 middle-aged healthy volunteers (40-71 year) we investigated effects of age-adapted Taekwondo training of 1 h a week during 1 year on various balance parameters, such as: motor orientation ability (primary outcome measure), postural and static balance test, single leg stance, one leg hop test, and a questionnaire. Motor orientation ability significantly increased in favor of the antero-posterior direction with a difference of 0.62° toward anterior compared to pre-training measurement, when participants corrected the tilted platform rather toward the posterior direction; female gender being an independent outcome predictor. On postural balance measurements sway path improved in all 19 participants, with a median of 9.3 mm/s (range 0.71-45.86), and sway area in 15 participants with 4.2 mm(2)/s (range 17.39-1.22). Static balance improved with an average of 5.34 s for the right leg, and with almost 4 s for the left. Median single leg stance duration increased in 17 participants with 5 s (range 1-16), and in 13 participants with 8 s (range 1-18). The average one leg hop test distance increased (not statistically significant) with 9.5 cm. The questionnaire reported a better "ability to maintain balance" in 16. In conclusion, our data suggest that age-adapted Taekwondo training improves various aspects of balance control in healthy people over the age of 40.

Levels of heparin-releasable TFPI are increased in first-ever lacunar stroke patients.

OBJECTIVES: New insights in the pathophysiology of lacunar stroke (LS) suggest that it is caused by increased permeability of the blood-brain barrier due to endothelial activation. Because endothelial cells are the major production and storage site of tissue factor pathway inhibitor (TFPI), this protein can be used as marker of endothelial activation. In this observational study we measured the different pools of TFPI, as a marker of endothelial function, in first-ever lacunar stroke patients. METHODS: We determined antigen levels of total and free full-length (FL) TFPI using ELISA in 149 patients and 42 controls. Heparin-releasable free FL TFPI was determined in a random subset of 17 patients and 15 controls. By brain MRI, we classified LS patients as having isolated lacunar infarct (ILA) or silent ischemic lesions (SILs). RESULTS: Plasma levels of total TFPI were highest in patients with SILs compared with those with ILA, but this association disappeared after correction for age and levels of low-density lipoprotein cholesterol. However, levels of heparin-releasable free FL TFPI were higher in patients than in controls. CONCLUSIONS: Although ambient plasma levels of total TFPI were not different in subtypes of LS, the increased levels of heparin-releasable TFPI in patients suggest a role of endothelial activation in the pathogenesis of LS.

Early treatment after stroke for the prevention of late epileptic seizures: a report on the problems performing a randomised placebo-controlled double-blind trial aimed at anti-epileptogenesis.

INTRODUCTION: Epileptic seizures in stroke patients are a common complication and adversely affect neurological outcome. We tried to perform a trial aimed at preventing the development of late poststroke seizures using levetiracetam. Levetiracetam is assumed to have anti-epileptogenic properties and might be suitable to prevent late epileptic seizures in stroke patients. METHODS: Stroke patients with a cortical syndrome and a modified Rankin score ≥ 3 or NIHSS ≥ 6 were treated with either levetiracetam 1500 mg daily divided in two doses or placebo during 12 weeks following stroke. Treatment was started within 7 days following stroke onset. RESULTS: Only 16 patients were included in this trial. Problems during the execution of this prophylactic trial concerned the assessment of the occurrence of epileptic seizures, a very slow inclusion rate, the use of anticonvulsive co-medication, continuation of the trial medication after discharge, and the evaluation of possible side effects of the trial medication. DISCUSSION: Due to too few participants, no conclusions could be drawn regarding the ability of levetiracetam to prevent poststroke seizures. The problems encountered during execution of this trial seem to be inherent to performing a trial aimed at preventing the development of epileptic seizures in stroke patients. CONCLUSIONS: A prophylactic trial in stroke patients aimed at preventing poststroke seizures and epilepsy seems not feasible.

Metabolic syndrome relates to lacunar stroke without white matter lesions: a study in first-ever lacunar stroke patients.

BACKGROUND: Metabolic syndrome (MetS) is a cluster of three or more of the following risk factors: obesity, elevated blood pressure, elevated triglyceride level, elevated glucose level, and low high-density lipoprotein level. Lacunar infarcts (LS) account for 25% of all ischemic strokes and are small, deeply located brain infarcts. Two different subtypes exist, which are distinguished by the presence of concomitant white matter lesions (WML) on brain imaging. We determined the prevalence of MetS in LS and the association between MetS with LS subtypes in a series of first-ever LS patients. METHODS: We included 92 patients with a first-ever LS, and 92 patients with a first-ever atheroslerotic cortical stroke (CS) matched for age and sex. LS subtypes were defined according to presence of concomitant WML. We defined MetS retrospectively according to previously defined standards. RESULTS: 35.9% of LS patients and 45.7% of CS patients had MetS (OR 0.67; 95% CI 0.37-1.20). MetS was more prevalent in LS without WML than in LS with WML (44.4 and 23.7%, respectively; OR 2.98; 95% CI 1.04-8.47). Similarly, MetS related more to CS compared to LS with WML (OR 2.56; 95% CI 1.03-6.37). CONCLUSION: MetS relates more strongly to LS without WML and to CS, than to LS with WML. Our results suggest a different underlying mechanism between LS without WML and CS, and lacunar stroke with WML.

Malignant melanoma of the skin in black South Africans: a 15-year experience.

AIM: To document the anatomical distribution of melanoma, extent of disease, results of treatment and survival among black patients in the north-eastern part of South Africa. METHODS: All available histological material was reviewed. All available addresses of patients were consulted to establish the status of patients treated in the drainage areas of, or referred to, Kalafong Hospital or Pretoria Academic Hospital retrospectively and prospectively for the 15-year period 1969 - 1983. RESULTS: Of the 185 patients with melanoma who were documented, 10 were eliminated for various reasons. Among the remaining 175 patients there were 128 documented deaths, 35 patients having died of melanoma within 1 year of presentation. Thirty patients survived for more than 3 years. Because of late presentation and the nature of the disease, malignant melanoma has a very poor prognosis in black patients in South Africa.

Thermally induced switching field distribution of a single CoPt dot in a large array.

Magnetic dot arrays with perpendicular magnetic anisotropy were fabricated by patterning Co(80)Pt(20)-alloy continuous films by means of laser interference lithography. As commonly seen in large dot arrays, there is a large difference in the switching field between dots. Here we investigate the origin of this large switching field distribution, by using the anomalous Hall effect (AHE). The high sensitivity of the AHE permits us to measure the magnetic reversal of individual dots in an array of 80 dots with a diameter of 180 nm. By taking 1000 hysteresis loops we reveal the thermally induced switching field distribution SFD(T) of individual dots inside the array. The SFD(T) of the first and last switching dots were fitted to an Arrhenius model, and a clear difference in switching volume and magnetic anisotropy was observed between dots switching at low and high fields.

Chlamydia pneumoniae infection enhances microglial activation in atherosclerotic mice.

The presence of Chlamydia pneumoniae in murine brain tissue was studied in atherosclerotic and non-atherosclerotic mice, after peritoneal injection. Furthermore, we investigated whether increased permeability of the blood-brain barrier was implicated in cerebral C. pneumoniae infection and whether intra-cerebral C. pneumoniae infection leads to microglial activation. Using a polymerase chain reaction, C. pneumoniae DNA was found in the brain tissue of 33% of the mice, 3, 7 and 21 days after infection. Atherosclerosis and age does not influence the extend of the cerebral infection. Semiquantitative analyses showed that intra-cerebral C. pneumoniae infection was not accompanied by an altered function of the blood-brain barrier. Microglial activation was assessed with immunohistochemistry, quantified in the hippocampus of each infected mouse and compared with mock infected. Enhanced microglial activation was found in the atherosclerotic mice. Since microglial activation is a key factor in a number of neuroinflammatory diseases, C. pneumoniae infection might play a role in these diseases.

Haptoglobin phenotype may alter endothelial progenitor cell cluster formation in cerebral small vessel disease.

Cerebral small vessel disease results in silent ischemic lesions (SIL) among which is leukoaraiosis. In this process, endothelial damage is probably involved. Endothelial progenitor cells (EPC), are involved in endothelial repair. By restoring the damaged endothelium, EPC could mitigate SIL and cerebral small vessel disease. Haptoglobin 1-1, one of three phenotypes of haptoglobin, relates to SIL and may therefore attenuate the endothelial repair by EPC. Our aim was to quantify EPC number and function and to assess haptoglobin phenotype and its effect on EPC function in patients with a high prevalence of SIL: lacunar stroke patients. We assessed EPC In 42 lacunar stroke patients and 18 controls by flow cytometry and culture with fetal calf serum, patient and control serum. We determined haptoglobin phenotype and cultured EPC with the three different haptoglobin phenotypes. We found that EPC cluster counts were lower in patients (96.9 clusters/well +/- 83.4 (mean +/- SD)), especially in those with SIL (85.0 +/- 64.3), than in controls (174.4 +/- 112.2). Cluster formation was inhibited by patient serum, especially by SIL patient serum, but not by control serum. Patients with haptoglobin 1-1 had less clusters in culture, and when haptoglobin 1-1 was added to EPC cultures, cluster numbers were lower than with the other haptoglobin phenotypes. We conclude that lacunar stroke patients, especially those with SIL, have impaired EPC cluster formation, which may point at decreased endothelial repair potential. The haptoglobin 1-1 phenotype is likely a causative factor in this impairment.

Limited role for C. pneumoniae, CMV and HSV-1 in cerebral large and small vessel atherosclerosis.

AIMS: To explore whether Chlamydia pneumoniae, Cytomegalovirus and Herpes Simplex Virus type 1 could be detected in large and small cerebral arteries, as well as in an area of brain parenchyma where white matter lesions (leukoaraiosis) can be found, in patients with clinically unmanifested cerebrovascular atherosclerosis. Methods and results( Arterial specimens from the basilar artery and middle cerebral artery, and brain samples from the basal ganglia and periventricular white matter were obtained. Neuropathological changes were assessed in Haematoxylin-Eosin stained sections. Polymerase chain reaction (PCR) was performed on paraffin embedded sections. Subsequently, we performed immunohistochemical staining on samples, which were found positive in PCR. We failed to detect C. pneumoniae, CMV, or HSV-1, in any of the cerebral large vessels. In the brain tissue, we found only one case positive for CMV, and one for C. pneumoniae. Conclusions (our findings suggest a limited role for C. pneumoniae, CMV and HSV-1 in cerebral large and small vessel atherosclerosis.

ESPRIT: is aspirin plus dipyridamole superior to aspirin alone in TIA or minor stroke patients?

Transient ischemic attack (TIA) or a (minor) ischemic stroke increases the risk of a recurrent stroke or death. Antiplatelet therapy with aspirin or clopidogrel is, in the absence of a potential cardiac embolic source, common practice to lower this risk. Until recently, adjuvant dipyridamole or low intensity oral anticoagulation were not generally prescribed in secondary prevention. In this article, we will summarize and discuss the published results of the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT). In this trial, treatments with anticoagulants, aspirin alone and the combination of aspirin plus dipyridamole were compared, in a multicenter, three-armed, randomized, open-label study in patients with TIA or minor stroke.

Dynamic cerebral autoregulation and cerebrovascular reactivity: a comparative study in lacunar infarct patients.

The major purpose of this study was to simultaneously evaluate dCA before and shortly after cerebral vasodilatation evoked by infusion of acetazolamide (ACZ). It was questioned if and to what degree dCA was changed after ACZ infusion. Using 15 mg kg(-1) ACZ infusion cerebrovascular reactivity (CVR) was assessed in 29 first ever lacunar stroke patients (19 M/10 F). During the CVR-test, the electrocardiogram, non-invasive finger arterial blood pressure (ABP) and middle cerebral artery blood flow velocity (CBFV) were recorded. DCA based on spontaneous blood pressure variations was evaluated in 24 subjects by linear transfer function analysis. Squared coherence, gain and phase angle in the frequency range of autoregulation (0.04-0.16 Hz) were compared before and after ACZ infusion. After ACZ infusion, median phase angle decreased significantly (p < 0.005 Wilcoxon) to 0.77 rad compared to a pre-test baseline value of 1.05 rad, indicating less efficient dCA due to ACZ. However, post-test phase values are still mostly within the normal range. Poor and statistically non-significant correlations were found between CVR and absolute dCA phase angle. It can be concluded that CVR testing with body weight adjusted infusion of ACZ lowers dCA performance but by no means exhausts dCA, suggesting that in this way maximal CVR is not determined. Characterizing dCA based on transfer function analysis of ABP to CBFV needs no provocation and adverse patient effects are minimal. The poor correlation between CVR and dCA phase angle supports an interpretation that CVR and dCA study different mechanisms of cerebrovascular control.

Virchow-Robin spaces relate to cerebral small vessel disease severity.

BACKGROUND AND PURPOSE: Virchow-Robin spaces (VRs) are perivascular spaces surrounding the deep perforating brain arteries. VRs dilatation is pathologic, and it could be a manifestation of cerebral small vessel disease. In the present study we assessed the relation between VRs and silent ischemic lesions in a cohort of patients with cerebral small vessel disease. METHODS: We divided dilated VRs on MRI (1.5 Tesla) into three semi-quantitative categories in 165 first ever lacunar stroke patients. We counted asymptomatic lacunar infarcts and graded white matter lesions, and compared the prevalence of vascular risk factors in different categories of VRs. We also determined independent predictors of silent ischemic lesions. RESULTS: VRs at basal ganglia level related to age, hypertension, asymptomatic lacunar infarcts, and white matter lesions. VRs at basal ganglia level predicted silent ischemic lesions (odds ratio 10.58 per higher VRs category; 95 %- confidence interval 3.40 - 32.92). CONCLUSION: Dilated VRs in the basal ganglia relate to the severity of cerebral small vessel disease and might be a manifestation of the same small vessel abnormality that causes silent ischemic lesions. This adds a role for VRs as a potential marker for small vessel disease.

Vascular mild cognitive impairment is highly prevalent after lacunar stroke but does not increase over time: a 2-year follow-up study.

UNLABELLED: Although ample research has been done into cognitive disorders occurring after stroke, relatively few data are available on the development and the course of vascularmild cognitive impairment (VMCI) after first-ever lacunar stroke. METHODS: A cohort of 95 patients with a first-ever symptomaticlacunar infarct, older than 40 years, MMSE>or=15 and no other neurological or major psychiatric deficits were included. Patients were assessed (clinically and with a neuropsychological test battery) at 1 and 24 months after stroke, and CT was repeated. VMCI was diagnosed when patients had a deficit in at least one cognitive domain, in the absence of dementia. RESULTS: Approximately 75% of the patients had VMCI at 1 month; this percentage was somewhat lower at 2 years. Only initial stroke severity was an independent predictor of VMCI after stroke. CONCLUSION: VMCI is highly prevalent after lacunar stroke, but does not increase during the first 2 years thereafter.

Reduced 5-HT1A- and GABAB receptor function in dorsal raphé neurons upon chronic fluoxetine treatment of socially stressed rats.

Autoinhibitory serotonin 1A receptors (5-HT(1A)) in dorsal raphé nucleus (DRN) have been implicated in chronic depression and in actions of selective serotonin reuptake inhibitors (SSRI). Due to experimental limitations, it was never studied at single-cell level whether changes in 5-HT(1A) receptor functionality occur in depression and during SSRI treatment. Here we address this question in a social stress paradigm in rats that mimics anhedonia, a core symptom of depression. We used whole cell patch-clamp recordings of 5-HT- and baclophen-induced G-protein-coupled inwardly rectifying potassium (GIRK) currents as a measure of 5-HT(1A)- and GABA(B) receptor functionality. 5-HT(1A)- and GABA(B) receptor-mediated GIRK-currents were not affected in socially stressed rats, suggesting that there was no abnormal (auto)inhibition in the DRN on social stress. However, chronic fluoxetine treatment of socially stressed rats restored anticipatory behavior and reduced the responsiveness of 5-HT(1A) receptor-mediated GIRK currents. Because GABA(B) receptor-induced GIRK responses were also suppressed, fluoxetine does not appear to desensitize 5-HT(1A) receptors but rather one of the downstream components shared with GABA(B) receptors. This fluoxetine effect on GIRK currents was also present in healthy animals and was independent of the animal's "depressed" state. Thus our data show that symptoms of depression after social stress are not paralleled by changes in 5-HT(1A) receptor signaling in DRN neurons, but SSRI treatment can alleviate these behavioral symptoms while acting strongly on the 5-HT(1A) receptor signaling pathway.

Tunnel spin polarization versus energy for clean and doped Al2O3 barriers.

The variation of the tunnel spin-polarization (TSP) with energy is determined using a magnetic tunnel transistor, allowing quantification of the energy dependent TSP separately for both ferromagnet/insulator interfaces and direct correlation with the tunnel magnetoresistance (TMR) measured in the same device. The intrinsic TSP is reduced below the Fermi level, and more strongly so for tunneling into empty states above the Fermi level. For artificially doped barriers, the low bias TMR decreases due to defect-assisted tunneling. Yet, this mechanism becomes ineffective at large bias, where instead inelastic spin scattering causes a strong TMR decay.

Opposite spin asymmetry of elastic and inelastic scattering of nonequilibrium holes injected into a ferromagnet.

The spin asymmetry of elastic and inelastic scattering of nonequilibrium holes injected into Co thin films is examined using a p-type magnetic tunnel transistor. Spin-dependent transmission yields a positive or negative magnetocurrent depending on Co thickness and hole energy. Up to a critical thickness of about 3 nm, (quasi)elastic scattering dominates with a short attenuation length (<1 nm) and preferential attenuation of holes in the majority spin bands, consistent with spin-wave emission. At a larger Co thickness, inelastic scattering dominates with a larger attenuation length ( approximately 4 nm) and opposite spin asymmetry.

NMDA receptors trigger neurosecretion of 5-HT within dorsal raphe nucleus of the rat in the absence of action potential firing.

Activity and calcium-dependent release of neurotransmitters from the somatodendritic compartment is an important signalling mechanism between neurones throughout the brain. NMDA receptors and vesicles filled with neurotransmitters occur in close proximity in many brain areas. It is unknown whether calcium influx through these receptors can trigger the release of somatodendritic vesicles directly, or whether postsynaptic action potential firing is necessary for release of these vesicles. Here we addressed this question by studying local release of serotonin (5-HT) from dorsal raphé nucleus (DRN) neurones. We performed capacitance measurements to monitor the secretion of vesicles in giant soma patches, in response to short depolarizations and action potential waveforms. Amperometric measurements confirmed that secreted vesicles contained 5-HT. Surprisingly, two-photon imaging of DRN neurones in slices revealed that dendritic calcium concentration changes in response to somatic firing were restricted to proximal dendritic areas. This implied that alternative calcium entry pathways may dominate the induction of vesicle secretion from distal dendrites. In line with this, transient NMDA receptor activation, in the absence of action potential firing, was sufficient to induce capacitance changes. By monitoring GABAergic transmission onto DRN 5-HT neurones in slices, we show that endogenous NMDA receptor activation, in the absence of postsynaptic firing, induced release of 5-HT, which in turn increased the frequency of GABAergic inputs through activation of 5-HT(2) receptors. We propose here that calcium influx through NMDA receptors can directly induce postsynaptic 5-HT release from DRN neurones, which in turn may facilitate GABAergic input onto these cells.

Thrombolysis for acute stroke with special emphasis on the very old: experience from a single Dutch centre.

The aim of this study was to describe the clinical experience in 184 consecutive stroke patients first-ever treated with recombinant tissue plasminogen activator (rt-PA) at a single Dutch centre, with special emphasis on results among the very old. Outcome parameters were the modified Rankin scale (mRs) at 3 months and symptomatic intracranial haemorrhage (SICH). Outcome was related to age. A total of 184 patients were treated of whom 45 were 80 years of age or older (24%). Sixty two (45%) of 139 patients < 80 years of age and 12 (27%) of 45 patients > or = 80 years of age had a favourable outcome defined as an mRs score of 0 or 1 (OR 2.21; 95% CI: 1.06 to 4.46). There was a good outcome (mRs score < or = 2) in 88 (63%) and 16 (36%) patients, respectively (OR 3.13; 95% CI: 1.55 to 6.30). SICH was observed in four of 139 (2.9%) patients < 80 years of age and in five of 45 (11.1%) patients > or = 80 years of age (OR 4.22; 95% CI: 1.08 to 16.46). The results of this study underline the uncertainty regarding the risk/benefit ratio of rt-PA treatment in acute stroke in patients over 80 years of age.

Focal or generalized vascular brain damage and vulnerability to depression after stroke: a 1-year prospective follow-up study.

BACKGROUND: Both the lesion location hypothesis and the vascular depression hypothesis have been proposed to explain the high incidence of depression in stroke patients. However, research studying both hypotheses in a single cohort is, at present, scarce. OBJECTIVE: To test the independent effects of lesion location (left hemisphere, anterior region) and of co-occurring generalized vascular damage on the development of depression in the first year after ischemic stroke, while other risk factors for depression are controlled for. METHODS: One hundred and ninety consecutive patients with a first-ever, supratentorial infarct were followed up for one year. CT was performed in the acute phase of stroke, while in 75 patients an additional MRI scan was also available. Depression was assessed at 1, 3, 6, 9, and 12 months after stroke using self-rating scales as screening tools and the SCID-I to diagnose depression according to DSM-IV criteria. RESULTS: Separate analyses of the lesion location hypothesis and the vascular depression hypothesis failed to reveal significant support for either of these biological models of post-stroke depression. Similar negative results appeared from one overall, multivariate analysis including variables of both focal and generalized vascular brain damage, as well as other non-cerebral risk factors. In addition, level of handicap and neuroticism were independent predictors of depression in this cohort, as has been reported previously. CONCLUSION: This study supports neither the lesion location nor the vascular depression hypothesis of post-stroke depression. A biopsychosocial model including both premorbid (prior to stroke) vulnerability factors, such as neuroticism and (family) history of depression, as well as post-stroke stressors, such as level of handicap, may be more appropriate and deserves further study.

Diazepam to improve acute stroke outcome: results of the early GABA-Ergic activation study in stroke trial. a randomized double-blind placebo-controlled trial.

BACKGROUND: We tested whether diazepam, a GABA-ergic drug that also inhibits brain nitric monoxide formation, improves acute stroke prognosis. METHODS: 880 patients, randomized within 12 h of acute stroke, received diazepam 10 mg or placebo by rectiole, as soon as possible, followed by 10-mg tablets twice daily for 3 days. Primary outcome was independence (Rankin score <3) at 3 months; secondary outcome was complete recovery (Barthel index >or=95 or Rankin score