Inflammation, edema and poor outcome are associated with hyperthermia in hypertensive intracerebral hemorrhages.

BACKGROUND AND PURPOSE: The deleterious effect of hyperthermia on intracerebral hemorrhage (ICH) has been studied. However, the results are not conclusive and new studies are needed to elucidate clinical factors that influence the poor outcome. The aim of this study was to identify the clinical factors (including ICH etiology) that influence the poor outcome associated with hyperthermia and ICH. We also tried to identify potential mechanisms involved in hyperthermia during ICH. METHODS: We conducted a retrospective study enrolling patients with non-traumatic ICH from a prospective registry. We used logistic regression models to analyze the influence of hyperthermia in relation to different inflammatory and endothelial dysfunction markers, hematoma growth and edema volume in hypertensive and non-hypertensive patients with ICH. RESULTS: We included 887 patients with ICH (433 hypertensive, 50 amyloid, 117 by anticoagulants and 287 with other causes). Patients with hypertensive ICH showed the highest body temperature (37.5 ± 0.8°C) as well as the maximum increase in temperature (0.9 ± 0.1°C) within the first 24 h. Patients with ICH of hypertensive etiologic origin, who presented hyperthermia, showed a 5.3-fold higher risk of a poor outcome at 3 months. We found a positive relationship (r = 0.717, P < 0.0001) between edema volume and hyperthermia during the first 24 h but only in patients with ICH of hypertensive etiologic origin. This relationship seems to be mediated by inflammatory markers. CONCLUSION: Our data suggest that hyperthermia, together with inflammation and edema, is associated with poor outcome only in ICH of hypertensive etiology.

Chronic periodontitis is associated with lacunar infarct: a case-control study.

BACKGROUND AND PURPOSE: Chronic periodontitis (ChP) and lacunar infarct (LI) are two common diseases amongst the elderly. Although several studies have shown an association between ischaemic stroke and ChP, little is known about the relationship between ChP and LI. The study aims to investigate whether ChP is associated with the presence of lacunar stroke. METHODS: An age- and gender-matched case-control study of 62 cases (subjects diagnosed with LI) and 60 controls is reported. Clinical periodontal measures (probing pocket depth, recession, clinical attachment level, full mouth plaque score and full mouth gingival bleeding on probing score) were assessed, and associated risk factors for periodontitis and lacunar stroke were ascertained by means of a structured questionnaire. RESULTS: Chronic periodontitis showed a strong association with LI after adjusting for common vascular risk factors (odds ratio 4.20; 95% confidence interval 1.81-10.20; P = 0.001). Likewise, severe ChP and LI also tended to be significantly associated, independent of other vascular covariates (odds ratio 3.53; 95% confidence interval 1.07-12.77; P = 0.04). CONCLUSIONS: Chronic periodontitis was independently associated with the presence of LI after adjusting for well-known vascular risk factors for lacunar stroke. Further observational studies are necessary to investigate the pathophysiological mechanisms that can explain this relationship.

Clinical practice guidelines for the diagnosis and management of Charcot-Marie-Tooth disease.

INTRODUCTION: Charcot-Marie-Tooth disease (CMT) is classified according to neurophysiological and histological findings, the inheritance pattern, and the underlying genetic defect. The objective of these guidelines is to offer recommendations for the diagnosis, prognosis, follow-up, and treatment of this disease in Spain. MATERIAL AND METHODS: These consensus guidelines were developed through collaboration by a multidisciplinary panel encompassing a broad group of experts on the subject, including neurologists, paediatric neurologists, geneticists, physiatrists, and orthopaedic surgeons. RECOMMENDATIONS: The diagnosis of CMT is clinical, with patients usually presenting a common or classical phenotype. Clinical assessment should be followed by an appropriate neurophysiological study; specific recommendations are established for the parameters that should be included. Genetic diagnosis should be approached sequentially; once PMP22 duplication has been ruled out, if appropriate, a next-generation sequencing study should be considered, taking into account the limitations of the available techniques. To date, no pharmacological disease-modifying treatment is available, but symptomatic management, guided by a multidiciplinary team, is important, as is proper rehabilitation and orthopaedic management. The latter should be initiated early to identify and improve the patient's functional deficits, and should include individualised exercise guidelines, orthotic adaptation, and assessment of conservative surgeries such as tendon transfer. The follow-up of patients with CMT is exclusively clinical, and ancillary testing is not necessary in routine clinical practice.

[Epidemiology of myasthenia gravis in the Iberian Peninsula and Latin America]. / Epidemiología de la miastenia grave en la península ibérica y Latinoamérica.

INTRODUCTION: Although today we live in a globalised world, the ties established between the Iberian Peninsula and the countries of Latin America are particularly strong, with important migratory flows. This connection may condition the development of diseases that involve a genetic influence, which may in turn be modulated by various environmental factors. The aim of this review is to determine the descriptive epidemiology of myasthenia gravis in the Iberian Peninsula and in Latin America. DEVELOPMENT: A literature search was conducted in Medline, LILACS and Google Scholar for the different countries of interest using the terms 'prevalence', 'incidence', 'epidemiology' and 'myasthenia gravis'. The methodology and quality were reviewed, and descriptive data about the study population as well as data on prevalence were extracted. CONCLUSIONS: Many countries lack epidemiological studies on myasthenia gravis and in others the data reported focus on one referral hospital, making it difficult to compare prevalence between countries. In the Iberian Peninsula, the prevalence is consistently above 100 cases x 106 inhabitants, the highest figures being found in the area of Osona (Barcelona) and in the province of Ourense. In Latin America, much lower prevalence figures are reported, generally below 100 x 106 inhabitants. There is a predominance of females in the early-onset forms (<50 years) and a clear increase in prevalence in the elderly population, especially in the very late onset forms (>65 years), where it is more frequent in men.

TITLE: Epidemiología de la miastenia grave en la península ibérica y Latinoamérica.Introducción. Aunque hoy en día vivimos en un mundo globalizado, los vínculos establecidos entre la península ibérica y los países de Latinoamérica son especialmente fuertes y con importantes flujos migratorios. Esta conexión puede condicionar la presentación de enfermedades que reconozcan una influencia genética, la cual puede ser modulada por diversos factores medioambientales. El objetivo de esta revisión es conocer la epidemiología descriptiva de la miastenia grave en la península ibérica y en Latinoamérica. Desarrollo. Se realizó una búsqueda bibliográfica en Medline, en LILACS y en Google Scholar para los diferentes países de interés con los términos 'prevalence', 'incidence', 'epidemiology' y 'myasthenia gravis'. Se revisó la metodología y la calidad, y se extrajeron datos descriptivos de la población estudiada, así como los datos de prevalencia. Conclusiones. Muchos países carecen de estudios epidemiológicos sobre la miastenia grave, y en otros, los datos comunicados se centran en un hospital de referencia, lo que hace difícil la comparación de la prevalencia entre los diferentes países. En la península ibérica, la prevalencia es constantemente superior a 100 casos × 106 habitantes, con las cifras más altas correspondientes a la comarca de Osona (Barcelona) y a la provincia de Ourense. En Latinoamérica se registran cifras mucho menores de prevalencia, generalmente inferiores a 100 × 106 habitantes. Se constata un predominio femenino en las formas de inicio precoz (<50 años) y un claro aumento de la prevalencia en la población anciana, sobre todo en las formas de inicio muy tardío (>65 años), en las que es más frecuente en los varones.

Increased levels of circulating endothelial progenitor cells in patients with ischaemic stroke treated with statins during acute phase.

BACKGROUND AND PURPOSE: Endothelial progenitor cells (EPCs) have been suggested to be a therapeutic option in ischaemic stroke. Our aim was to study whether statin treatment during acute phase could increase circulating EPCs after acute ischaemic stroke. METHODS: We studied 48 patients with a first-ever non-lacunar ischaemic stroke (<12 h from stroke onset). Sixteen patients received statin treatment (20 mg atorvastatin/day) during the first 4 days. We defined the EPC increment during the first week as the difference in the number of early outgrowth colony-forming unit-endothelial cell (CFU-EC) between day 7 and at admission (previous to atorvastatin treatment). Serum levels of vascular endothelial growth factor and active matrix metalloproteinase 9 (determined by ELISA), and nitric oxide metabolites (NOx) (determined by high-performance liquid chromatography) were measured at admission, 24 and 72 h, and day 7. RESULTS: Colony-forming unit-endothelial cells were similar at baseline between patients treated (n = 16) and non-treated (n = 32) with statins (10.1 ± 3.9 vs. 7.9 ± 6.9 CFU-EC, P = 0.223). However, patients treated with statins showed a higher EPC increment (24.0 ± 17.3 vs. 6.0 ± 17.8 CFU-EC, P = 0.002) during the first week. An EPC increment ≥ 4 CFU-EC predicted with the highest sensitivity (88%) and specificity (92%) the probability of good outcome (area under the curve 0.903, P < 0.0001). Statin treatment (OR, 13.1; CI 95%, 2.2-76.9, P = 0.004) was independently associated with an EPC increment ≥ 4 CFU-EC after adjustment for confounder factors, but this association was lost when adjusting for NOx levels. CONCLUSIONS: Statin treatment for 4 days may increase circulating EPC levels, probably by NO-related mechanisms.

High serum levels of leptin are associated with post-stroke depression.

BACKGROUND: Depression is a frequent mood disorder that affects around 33% of stroke patients and has been associated with both poorer outcome and increased mortality. Our aim was to test the possible association between inflammatory and neurotrophic molecular markers and the development of post-stroke depression. METHOD: We studied 134 patients with a first episode of ischemic stroke without previous history of depression or speech disorders. We screened for the existence of major depression symptoms in accordance with DSM-IV criteria and a Yesavage Geriatric Depression Scale (GDS) score >11 at discharge and 1 month after stroke. At these times, serum levels of molecular markers of inflammation [interleukin (IL)-1beta, IL-6, intracellular adhesion molecule 1 (ICAM-1), tumor necrosis factor (TNF)-alpha, leptin and high-sensitivity C-reactive protein (hs-CRP)] and neurotrophic factors [brain-derived neurotrophic factor (BDNF)] were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Twenty-five patients (18.7%) were diagnosed as having major depression at discharge. Out of 104 patients who completed the follow-up period, 23 were depressed at 1 month (22.1%). Patients with major depression showed higher serum leptin levels at discharge [43.4 (23.4-60.2) v. 6.4 (3.7-16.8) ng/ml, p<0.001] and at 1 month after stroke [46.2 (34.0-117.7) v. 6.4 (3.4-12.2) ng/ml, p<0.001). Serum levels of leptin >20.7 ng/ml were independently associated with post-stroke depression [odds ratio (OR) 16.4, 95% confidence interval (CI) 5.2-51.5, p<0.0001]. Leptin levels were even higher in the eight patients who developed depression after discharge [114.6 (87.6-120.2) v. 7.2 (3.6-13.6) ng/ml, p<0.0001]. CONCLUSIONS: Serum leptin levels at discharge are found to be associated with post-stroke depression and may predict its development during the next month.

Human recombinant glutamate oxaloacetate transaminase 1 (GOT1) supplemented with oxaloacetate induces a protective effect after cerebral ischemia.

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment.

proMetalloproteinase-10 is associated with brain damage and clinical outcome in acute ischemic stroke.

BACKGROUND: Matrix metalloproteinases (MMPs) mediate tissue injury during stroke but also neurovascular remodeling and we have shown that MMP-10 is involved in atherothrombosis. OBJECTIVE: The purpose of this study was to examine the relationship between proMMP-10 and clinical outcome, assessing inflammatory and proteolytic markers, in patients with acute ischemic stroke. METHODS: We prospectively studied 76 patients with ischemic stroke treated with tPA within the first 3 h from symptom onset, compared with 202 non-tPA-treated ischemic stroke patients and 83 asymptomatic subjects. Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS). Hemorrhagic transformation (HT) and severe brain edema were diagnosed by cranial CT. Good functional outcome was defined as a modified Rankin scale score ≤ 2 at 90 days. Serum levels of MMP-9, proMMP-10, TIMP-1, tumor necrosis factor-α (TNFα), interleukin-6 and cellular fibronectin were measured at admission. The effect of TNFα on endothelial proMMP-10 was assessed in vitro. RESULTS: Serum proMMP-10 concentration in ischemic stroke patients, non-treated or treated with t-PA, which was higher than age-matched healthy subjects (P < 0.0001), was independently associated with higher infarct volume, severe brain edema, neurological deterioration and poor functional outcome at 3 months (all P < 0.05), but not with HT. proMMP-10 levels were also independently and positively associated with circulating levels of TNFα (P < 0.0001), which induced its endothelial expression in vitro, both mRNA and protein. MMP-9, however, was only associated with HT and severe edema (all P < 0.05). CONCLUSIONS: Increased serum proMMP-10 after acute ischemic stroke, associated with TNFα, is a new marker of brain damage and poor outcome.

Association of growth factors with arterial recanalization and clinical outcome in patients with ischemic stroke treated with tPA.

SUMMARY BACKGROUND: Growth factors (GF) such as vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and granulocyte-colony stimulating factor (G-CSF) have been associated with greater efficacy of tissue plasminogen activator (tPA) in experimental studies. OBJECTIVES: To study the association of these GF with arterial recanalization and clinical outcome in patients with acute ischemic stroke treated with tPA. METHODS: We prospectively studied 79 patients with ischemic stroke attributable to MCA occlusion treated with i.v. tPA within the first 3 h from onset of symptoms. Continuous transcranial color-coded sonography (TCCS) was performed during the first 2 h after tPA bolus to assess early MCA recanalization. Hemorrhagic transformation (HT) was classified according to ECASS II definitions. Good functional outcome was defined as a Rankin scale score of 0-2 at 90 days. GF levels were determined by ELISA. RESULTS: Mean serum levels of VEGF, G-CSF and Ang-1 at baseline were significantly higher in patients with early MCA recanalization (n = 30) (all P < 0.0001). In the multivariate analysis, serum levels of VEGF (OR, 1.03), G-CSF (OR, 1.02) and Ang-1 (OR, 1.07) were independently associated with early MCA recanalization (all P < 0.0001). On the other hand, patients with parenchymal hematoma (PH) (n = 20) showed higher levels of Ang-1 (P < 0.0001). Ang-1 (OR, 1.12; P < 0.0001) was independently associated with PH, whereas patients with good outcome (n = 38) had higher levels of G-CSF (P < 0.0001). G-CSF was independently associated with good outcome (OR, 1.12; P = 0.036). CONCLUSIONS: These findings suggest that GF may enhance arterial recanalization in patients with ischemic stroke treated with t-PA, although they might increase the HT.

[Reorganisation of the cerebral vasculature following ischaemia]. / Reorganización de la vascularización cerebral tras la isquemia.

INTRODUCTION AND DEVELOPMENT: Cerebral function needs a constant oxygen and glucose supply. This is why the regulation of cerebral blood flow is critical for the maintenance of neuronal function. Therefore, vascular system in adult brain is extremely stable and does not withstand big changes under physiological conditions. However, when blood flow is interrupted due to a focal cerebral ischemia the collateral tissue is partially affected, this is known as ischemic penumbra. Although its functionality is affected, this tissue is viable thanks to the collateral blood flow, and it releases angiogenic factors that induce proliferation of endothelial cells and migration of endothelial progenitor cells for the formation of new blood vessels. Angiogenesis induction and new vessel generation allow neurorepair processes, including neurogenesis and synaptogenesis. These two processes should be coupled with angiogenesis in order to contribute to functional recovery of patients who suffered a cerebral infarct. Therefore, angiogenesis could be one of the therapeutic options in ischemic stroke treatment. Nevertheless, some angiogenic factors such as vascular endothelial growth factor, platelet derived growth factor and angiopoyetin also increase vascular permeability which can produce hemorrhagic transformation. CONCLUSIONS: Hence, the knowledge of molecular mechanisms that regulate angiogenesis after an ischemic stroke could contribute to the development of a new therapeutic option based on angiogenesis as a vehicle to promote neurorepair and functional recovery.

Subclinical keratoconus and inflammatory molecules from tears.

BACKGROUND/AIMS: Tissue degradation in corneal thinning disorders, such as keratoconus (KC), involves the expression of inflammatory mediators. The purpose of this study was to determine the levels of proinflammatory cytokines and matrix metalloproteinase 9 (MMP-9) in tears from both eyes of unilateral keratoconus (KC) patients. METHODS: Thirty patients diagnosed as having asymmetrical KC (30 KC eyes, and 30 subclinical KC eyes) and 20 normal control subjects (one eye) were studied in a prospective, cross-sectional study. Keratoconus screening programmes were performed on these participants. Ten microlitres of tears was collected from each eye. The concentrations of cytokines (interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha)) and MMP-9 were measured by ELISA. RESULTS: Mean values for IL-6 levels were similar in KC and subclinical KC samples (5.5 (4.9 to 6.9) vs 5.7 (4.5 to 6.2) pg/ml, p = 0.131), but significantly higher in relation to the control group (2.2 (1.0 to 4.1) pg/ml, p<0.0001). Significant differences were found in TNF-alpha levels between KC and subclinical KC eyes (5.4 (4.1 to 6.8) vs 4.8 (4.2 to 6.0) pg/ml, p = 0.032) and control group (1.8 (1.5 to 2.3) pg/ml, p<0.0001). Increased values of MMP-9 were found in KC (59.4 (50.6 to 66.1) ng/ml) vs subclinical KC eye (7.0 (4.8 to 8.6) ng/ml) (p<0.0001). MMP-9 levels in the control group (6.1 (3.9 to 8.3) ng/ml) and subclinical KC were similar (p = 0.203). CONCLUSIONS: IL-6 and TNF-alpha are overexpressed in the tears of subclinical and KC eyes. Increased MMP-9 levels were found only in the KC eye. These results indicate that the pathogenesis of KC may involve chronic inflammatory events.

Inflammation markers and prediction of post-stroke vascular disease recurrence: the MITICO study.

OBJECTIVE: Vascular disease recurrence following stroke is the main cause of morbidity and mortality. The MITICO study was designed to assess the prognostic value of markers of inflammation in relation to the risk of recurrence of vascular disease. PATIENTS AND METHODS: Multi-centered prospective observational study, in patients with ischemic stroke not receiving anti-coagulation therapy and who were recruited within 1-3 months from stroke onset. Blood samples were obtained at baseline and follow- up for the determination of high-sensitive C reactive protein (CRP), IL-6, IL-10, ICAM-1, VCAM- 1, MMP-9 and cellular fibronectin. Four follow-up visits within the first year were to rule out recurrence. RESULTS: Of 965 patients from 65 hospitals, 780 (aged 67.5+/-11.2 years, 33.6 % female) were valid for main analysis. One-hundred and three patients (13.2 %) had a new adverse vascular event and 116 patients (14.9 %) a vascular event or vascular death (66.4 % stroke, 21.5 % coronary and 12.1 % peripheral). Levels of IL-6 > 5 pg/mL and VCAM-1 > 1350 ng/mL (ROC curve analyses) were associated with vascular disease recurrence risk (OR: 28.7; 95 % CI: 14.2-58.0 vs. OR: 4.1; 95 % CI: 2.4-7.1, respectively) following adjustment for confounding variables. Risk of adverse vascular event or death from vascular disease were associated with IL-6 (OR: 21.2; 95 % CI: 11.6-38.7) and VCAM-1 (OR: 3.8; 95 % CI: 2.3-6.4). CONCLUSIONS: Baseline values of IL-6 > 5 pg/mL and VCAM-1 > 1350 ng/mL increase 21-fold and 4-fold, respectively, the risk of new vascular disease event or death from vascular disease in patients with ischemic stroke not receiving anti-coagulation treatment.

[Molecular markers are associated with early computed tomography ischemic changes]. / Marcadores moleculares asociados a signos precoces de isquemia en tomografía computarizada cerebral.

INTRODUCTION: During brain ischemia, neurotoxicity, neuroinflammation and blood-brain barrier (BBB) disruption mechanisms are involved, leading to necrosis, edema and hemorrhagic transformation. Cranial computed tomography (CT) is the most widely used method in the diagnosis of acute stroke, and its early performance may help in the selection of patients for certain treatments. Our objective is to identify molecular markers of neuroexcitotoxicity, neuroinflammation and BBB disruption in the acute phase of stroke that might be associated with early ischemic CT signs. METHODS: 311 patients with ischemic stroke within the first 24 h from symptoms onset were prospectively included. We established tres groups based on the time between symptom onset and hospital arrival: < or = 6 h, between 6 and 12 h and >12 h. Cranial CT was performed at admission to evaluate early ischemic signs according to the Alberta Stroke Program Early CT Score (ASPECTS). Blood samples were taken at admission for the determination of molecular markers of neuroexcitotoxicity (glutamate), neuroinflammation (interleukin [IL]-6) and BBB disruption (metalloproteinase [MMP]-9). RESULTS: Patients with ASPECTS score < or =7 showed a worse early and late prognosis. Glutamate >134.4 microM (OR: 9.7; CI 95%: 4.2-22.5; p<0.001), IL-6>15.5 pg/mL (OR: 4.4; CI 95%: 2.1-9.4; p<0.001) and MMP-9 > 87.2 ng/mL (OR: 18.4; CI 95%: 7.2-47.1; p<0.001) were associated with ASPECTS score < or =7. In the logistic regression model, only glutamate >134.4 microM/l in the first 6 h (OR: 13.2; CI95%: 5.4-31.3; p<0.001), IL-6>15.5 pg/mL from 6 to 12 h (OR: 10.5; CI 95 %: 4.1-26.7; p<0.001) and MMP-9 >87.2 ng/ml after 12 h (OR: 24.2; CI 95%: 4.8- 50.2; p < 0.001) were independently associated with ASPECTS score < or = 7. CONCLUSIONS: The ASPECTS score may be considered as a surrogate marker of early neurological deterioration and final infarct volume, and associated with molecular markers of neuroexcitotoxicity, neuroinflammation and BBB disruption.

[Cognitive impairment associated to leukoaraiosis: its pathophysiology, clinical manifestations and treatment]. / Deterioro cognitivo asociado a la leucoaraiosis: fisiopatología, manifestaciones clínicas y tratamiento.

INTRODUCTION AND DEVELOPMENT: Leukoaraiosis is a radiological term which refers to white matter disturbances observed as a hypodensity in computed tomography and hyperintensity in T2-weighted magnetic resonance image. The most accepted theory to explain the mechanism of production of leukoaraiosis is chronic ischemia, due to a damage in penetrating arteries. It is an entity with increasing interest, since it is associated with the presence of cognitive impairment. Clinical manifestations in relation with cognitive functions range from mild affectation to dementia, affecting the processing speed and executive functions. CONCLUSIONS: It seems that the control of vascular risk factors slow the progression of leukoaraiosis and cognitive impairment, and although there are no really effective treatment, it seems that some drugs, such as acetylcholinesterase inhibitors or NMDA-receptor antagonists, exert a beneficial effect, although slight, in cognitive functions.

Delayed post-ischemic administration of CDP-choline increases EAAT2 association to lipid rafts and affords neuroprotection in experimental stroke.

Glutamate transport is the only mechanism for maintaining extracellular glutamate concentrations below excitotoxic levels. Among glutamate transporters, EAAT2 is responsible for up to 90% of all glutamate transport and has been reported to be associated to lipid rafts. In this context, we have recently shown that CDP-choline induces EAAT2 translocation to the membrane. Since CDP-choline preserves membrane stability by recovering levels of sphingomyelin, a glycosphingolipid present in lipid rafts, we have decided to investigate whether CDP-choline increases association of EAAT2 transporter to lipid rafts. Flotillin-1 was used as a marker of lipid rafts due to its known association to these microdomains. After gradient centrifugation, we have found that flotillin-1 appears mainly in fractions 2 and 3 and that EAAT2 protein is predominantly found colocalised with flotillin-1 in fraction 2. We have also demonstrated that CDP-choline increased EAAT2 levels in fraction 2 at both times examined (3 and 6 h after 1 g/kg CDP-choline administration). In agreement with this, [(3)H] glutamate uptake was also increased in flotillin-associated vesicles obtained from brain homogenates of animals treated with CDP-choline. Exposure to middle cerebral artery occlusion also increased EAAT2 levels in lipid rafts, an effect which was further enhanced in those animals receiving 2 g/kg CDP-choline 4 h after the occlusion. Infarct volume measured at 48 h after ischemia showed a reduction in the group treated with CDP-choline 4 h after occlusion. In summary, we have demonstrated that CDP-choline redistributes EAAT2 to lipid raft microdomains and improves glutamate uptake. This effect is also found after experimental stroke, when CDP-choline is administered 4 h after the ischemic occlusion. Since we have also shown that this delayed post-ischemic administration of CDP-choline induces a potent neuroprotection, our data provides a novel target for neuroprotection in stroke.

High plasma glutamate concentrations are associated with infarct growth in acute ischemic stroke.

BACKGROUND: Excitotoxic and inflammatory mechanisms have been demonstrated as mediating early neurologic deterioration (END) in patients with cerebral infarction. Here we investigate whether molecular markers associated with END are related to the volume and outcome of the diffusion weighted image (DWI) lesion in acute ischemic stroke. METHODS: MRI was performed on admission and at 72 hours in 197 patients with acute hemispheric infarction of <12 hours' duration. DWI lesion enlargement was calculated as the absolute difference between volumes on admission and day 3 of evolution. NIH Stroke Scale was scored at the same intervals. END was defined as an increase >/=4 points within the 3 days. Glutamate, l-arginine, interleukin-6 (IL-6), and tumor necrosis factor-alpha levels were analyzed in blood samples obtained on admission. RESULTS: DWI lesion growth was found in 144 (73%) patients (median increase 38 [6.5, 83.4] cm(3)) and END occurred in 58 (29.4%) patients. Baseline glutamate (r = 0.71), l-arginine (r = -0.35), and IL-6 levels (r = 0.50) showed a high and significant correlation with the DWI lesion enlargement (all p < 0.001). After adjustment for potential confounders, glutamate levels were the only molecular marker associated with DWI lesion enlargement at 72 hours (beta = 0.21; SD = 0.07; p = 0.004). CONCLUSIONS: Molecular markers of early neurologic deterioration may play a role as mediators of lesion growth in cerebral ischemia. Plasma glutamate concentration is the most powerful and independent predictor biomarker of lesion enlargement in the acute phase of ischemic stroke, and so may well be useful as a signature of tissue at risk of infarction.

[Application of proteomics to neurological diseases]. / Aplicación de la proteómica a las enfermedades neurológicas.

Proteomic is a set of tools that allows the separation and identification of proteins expressed by a cell, tissue or organism. Two-dimensional electrophoresis is the central tool that allows qualitative and quantitative comparisons of protein patterns between samples. Differential analysis of protein expression patterns in different neurological diseases (stroke, Alzheimer, Parkinson, amyotrophic lateral sclerosis, Hungtington, epilepsy) allows the identification of diagnostic and/or prognostic biomarkers. Subsequently, validation of these markers may help to identify new diagnostic and therapeutic targets.