Targeting P2X4 and P2X7 receptors in multiple sclerosis.

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by massive infiltration of immune cells, demyelination, and axonal loss. However, spontaneous myelin repair can occur during the course of the disease. A major component of this regenerative process is a robust innate immune response consisting of infiltrating macrophages and brain microgliosis. Therefore, specifically targeting myeloid cells could be an attractive therapeutic approach. Purinergic receptors control not only immune cell function together with the activation of microglia and astrocytes, but also neuronal and oligodendroglial survival in the pathology. Thus, targeting these receptors can modulate a whole variety of responses. In this review, we will summarize recent findings highlighting the potential of P2X4 and P2X7 as therapeutic targets for MS.

Purinergic receptors in multiple sclerosis pathogenesis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system, characterized by the presence of focal lesions in white and grey matter with peripheral immune cells infiltration. Purinergic receptors control immune cell function as well as neuronal and oligodendroglial survival, and the activation of astrocytes and microglia, the endogenous brain immune cells. In particular, ionotropic purinergic receptors P2X4 and P2X7 and metabotropic receptor P2Y12 are differently expressed along the disease and their activation or blockage modifies the course of texperimental autoimmune encephalomyelitis (EAE), the dominant animal model of MS. In this review, we will summarize emerging evidence of the role of these three receptor types as potential MS biomarkers and therapeutic targets.

Oral anticoagulation and left atrial appendage closure: a new strategy for recurrent cardioembolic stroke.

BACKGROUND AND PURPOSE: There are no recommendations regarding how to treat cardioembolic recurrent strokes when patients are well anticoagulated. We evaluated the safety and efficacy of combining oral anticoagulation (OAC) with percutaneous left atrial appendage closure (LAAC) in patients with well-anticoagulated atrial fibrillation (AF) with recurrent strokes. METHODS: In an explorative, prospective, observational study, LAAC was performed in patients with AF with at least two ischaemic strokes in the previous year, despite good anticoagulation using the Amplatzer Cardiac Plug (St Jude Medical, St Paul, MN, USA) or Amulet Abbot device (Abbot Vascular, Santa Clara, CA, USA). We recorded age, type of AF, CHA2 DS2 -VASC and HAS-BLED scores, types of OAC and risk factors. After closure, treatment with aspirin (100 mg/day) was continued for 3 months in combination with indefinite OAC. Clinical status, recurrent embolisms and bleeding complications were recorded during follow-up. RESULTS: A total of 19 patients were included (mean age, 72.1 ± 9.6 years; mean CHA2 DS2 -VASC score, 5.3 ± 1.48; mean number of previous strokes, 2.78 ± 1.15). Thirteen had spontaneous echocardiographic contrast and all had dilatation of the left atrium. Eighteen patients had a multilobulated left atrial appendage, 17 with 'chicken-wing' morphology and one patient had a left atrial appendage thrombus. There were no complications during the procedure. Only one patient had a transient ischaemic attack and no major bleeding occurred during a mean follow-up of 17.4 ± 11.5 months. CONCLUSION: Combination therapy with indefinite OAC plus LAAC in patients with AF with recurrent strokes despite good anticoagulation should be considered in order to prevent a new stroke.

Synaptic activity protects against AD and FTD-like pathology via autophagic-lysosomal degradation.

Changes in synaptic excitability and reduced brain metabolism are among the earliest detectable alterations associated with the development of Alzheimer's disease (AD). Stimulation of synaptic activity has been shown to be protective in models of AD beta-amyloidosis. Remarkably, deep brain stimulation (DBS) provides beneficial effects in AD patients, and represents an important therapeutic approach against AD and other forms of dementia. While several studies have explored the effect of synaptic activation on beta-amyloid, little is known about Tau protein. In this study, we investigated the effect of synaptic stimulation on Tau pathology and synapses in in vivo and in vitro models of AD and frontotemporal dementia (FTD). We found that chronic DBS or chemically induced synaptic stimulation reduced accumulation of pathological forms of Tau and protected synapses, while chronic inhibition of synaptic activity worsened Tau pathology and caused detrimental effects on pre- and post-synaptic markers, suggesting that synapses are affected. Interestingly, degradation via the proteasomal system was not involved in the reduction of pathological Tau during stimulation. In contrast, chronic synaptic activation promoted clearance of Tau oligomers by autophagosomes and lysosomes. Chronic inhibition of synaptic activity resulted in opposite outcomes, with build-up of Tau oligomers in enlarged auto-lysosomes. Our data indicate that synaptic activity counteracts the negative effects of Tau in AD and FTD by acting on autophagy, providing a rationale for therapeutic use of DBS and synaptic stimulation in tauopathies.

Ictus en adultos jóvenes: incidencia, factores de riesgo, tratamiento y pronóstico / Stroke in young adults: incidence rate, risk factors, treatment and prognosis

Objetivos. Analizar la incidencia, los factores de riesgo, la etiología, el tratamiento y la evolución clínica de pacientes jóvenes con ictus. Pacientes y métodos. Registro retrospectivo de pacientes ≤ 55 años ingresados en una Unidad de Ictus durante el año 2014. Se recogió la incidencia sobre el total de ictus y se analizaron datos demográficos, factores de riesgo, grado de estrés, tipo y etiología del ictus, tratamientos de reperfusión y evolución clínica. Resultados. Se incluyó a 110 pacientes, la mayoría hombres (60,9%, ratio 1,6:1). La incidencia fue del 13,3% (110 de 830 ictus). La mayoría de los pacientes tenía factores de riesgo vascular. El tabaquismo fue el más frecuente (56,4%), seguido de la hipertensión arterial (50%), dislipidemia (42,7%), obesidad (33%), diabetes (18,2%) y cardiopatías embolígenas (12,7%). El 64,3% de las cardiopatías y el 51,1% de las dislipidemias se descubrieron durante el ingreso. El 57,2% de los pacientes presentaban estrés psicosocial en la etapa previa al ictus. El 83,6% de los ictus fueron isquémicos, el 12,7% hemorrágicos y el 3,6% trombosis de senos venosos. De los ictus isquémicos, el 30,4% fueron criptogénicos, el 23,9% lacunares, el 16,3% por causas infrecuentes, el 15,2% aterotrombóticos y el 14,1% cardioembólicos. El 78,6% de las hemorragias cerebrales fueron hipertensivas. El 23,3% de los ictus isquémicos recibieron tratamientos de reperfusión en fase aguda y se consiguieron niveles de independencia funcional a los 3 meses del 62,5%. Conclusiones. La mayoría de los ictus en pacientes ≤ 55 años parecen relacionarse con una elevada prevalencia de factores de riesgo vascular clásicos y posiblemente de estrés psicosocial (AU)

Objectives. To analyse the incidence, risk factors, aetiology, treatment and clinical evolution of young patients with stroke. Patients and methods. Retrospective registry of patients aged 55 years or younger hospitalised in a stroke unit during 2014. We recorded the incidence rate for all strokes and analysed demographic data, risk factors, degree of stress, stroke type and aetiology, reperfusion treatments and clinical evolution. Results. The study included 110 patients, the majority of whom were men (60.9%, 1.6:1 ratio). The incidence rate was 13.3% (110 of 830 strokes). Most of the patients had cardiovascular risk factors. Smoking was the most common risk factor (56.4%), followed by arterial hypertension (50%), dyslipidaemia (42.7%), obesity (33%), diabetes (18.2%) and emboligenic heart disease (12.7%). Some 64.3% of the heart disease cases and 51.1% of the dyslipidaemia cases were discovered during hospitalisation. Some 57.2% of the patients experienced psychosocial stress in the stage prior to the stroke. Some 83.6% of the stroke cases were ischaemic, 12.7% were haemorrhagic and 3.6% were venous sinus thrombosis. Of the ischaemic stroke cases, 30.4% were cryptogenic, 23.9% were lacunar, 16.3% were from uncommon causes, 15.2% were atherothrombotic and 14.1% were cardioembolic. Some 78.6% of the cerebral haemorrhage cases were hypertensive. Some 23.3% of the ischaemic stroke cases underwent reperfusion treatments in the acute phase, achieving levels of functional independence at 3 months of 62.5%. Conclusions. The majority of stroke events in patients 55 years of age or younger appear to be related to a high prevalence of classical cardiovascular risk factors and possibly to psychosocial stress (AU)

Stroke in young adults: Incidence rate, risk factors, treatment and prognosis. / Ictus en adultos jóvenes: incidencia, factores de riesgo, tratamiento y pronóstico.

OBJECTIVES: To analyse the incidence, risk factors, aetiology, treatment and clinical evolution of young patients with stroke. PATIENTS AND METHODS: Retrospective registry of patients aged 55 years or younger hospitalised in a stroke unit during 2014. We recorded the incidence rate for all strokes and analysed demographic data, risk factors, degree of stress, stroke type and aetiology, reperfusion treatments and clinical evolution. RESULTS: The study included 110 patients, the majority of whom were men (60.9%, 1.6:1 ratio). The incidence rate was 13.3% (110 of 830 strokes). Most of the patients had cardiovascular risk factors. Smoking was the most common risk factor (56.4%), followed by arterial hypertension (50%), dyslipidaemia (42.7%), obesity (33%), diabetes (18.2%) and emboligenic heart disease (12.7%). Some 64.3% of the heart disease cases and 51.1% of the dyslipidaemia cases were discovered during hospitalisation. Some 57.2% of the patients experienced psychosocial stress in the stage prior to the stroke. Some 83.6% of the stroke cases were ischaemic, 12.7% were haemorrhagic and 3.6% were venous sinus thrombosis. Of the ischaemic stroke cases, 30.4% were cryptogenic, 23.9% were lacunar, 16.3% were from uncommon causes, 15.2% were atherothrombotic and 14.1% were cardioembolic. Some 78.6% of the cerebral haemorrhage cases were hypertensive. Some 23.3% of the ischaemic stroke cases underwent reperfusion treatments in the acute phase, achieving levels of functional independence at 3 months of 62.5%. CONCLUSIONS: The majority of stroke events in patients 55 years of age or younger appear to be related to a high prevalence of classical cardiovascular risk factors and possibly to psychosocial stress.

Los estudios prospectivos de pacientes consecutivos con enfermedad tromboembólica venosa no identifican a todos los pacientes en riesgo. Análisis multicéntrico ambispectivo del grupo Contaminatep / Prospective studies of consecutive patients with venous thromboembolic disease fail to identify all patients at risk. Multicenter, ambispective analysis of the Contaminatep Group

INTRODUCCIÓN: nuestro grupo ha comenzado un trabajo para estudiar la relación entre la incidencia de TEP y la contaminación ambiental. Para establecer una relación, es una condición metodológica fundamental contar con todos los casos incidentes en un periodo de tiempo. Por este motivo diseñamos este estudio, para valorar la eficacia de recogida de pacientes consecutivos con TEP. MATERIAL Y MÉTODOS: realizamos un estudio ambispectivo, multicéntrico, de un año de duración. En una primera fase se incluyeron prospectivamente todos los casos que ingresaron con diagnóstico de TEP y posteriormente, de forma retrospectiva, realizamos una revisión de los registros hospitalarios de cada uno de los centros participantes. Así, calculamos la eficacia dividiendo el número de casos incidentes en fase prospectiva por el número total de casos reclutados en ambas fases. RESULTADOS: desde febrero 2012 a febrero 2013 se reclutaron 839 pacientes (440 prospectivamente). El reclutamiento prospectivo presentó una eficacia de detección de TEP del 52,4%, mostrando variabilidad según el centro (29,3 - 100%). Cuando analizamos sólo a los pacientes con TEP agudo sintomático idiopático, la eficacia fue del 59,8 %, con variabilidad según centro (31,7 - 100%). La eficacia de reclutamiento de pacientes con TEP secundario o idiopático fue de 42,1% vs. 59,8%, respectivamente (p < 0,001). CONCLUSIONES: en los estudios prospectivos, el porcentaje de pacientes no diagnosticados no es desdeñable. Los resultados de este estudio nos deben hacer pensar en estrategias adicionales para reclutar pacientes consecutivos de forma correcta, principalmente en aquellos estudios donde la pérdida de pacientes supondría un sesgo a la hora de emitir conclusiones

INTRODUCTION: we are studying the relationship between the incidence of pulmonary embolism (PE) and air pollution, and all symptomatic PE were needed over a period of time to establish a relationship. For this reason we designed this study, to assess the efficacy of collection consecutive patients with PE. METHODS: ambispective, multicenter study, from February 2012 to February 2013. In the first phase, we included prospectively all cases admitted at the hospital with PE diagnosis, and in the second phase, we reviewed retrospectively, hospital records from each participating center. So, we calculate the efficacy by dividing the number of incident cases in prospective phase by the total number of cases recruited in both phases. RESULTS: during one year, 839 patients were recruited (440 prospectively). The prospective recruitment presented a PE efficacy detection of 52.4%, showing variability according to the center between 29.3 to 100%. When we analyzed only patients with idiopathic symptomatic PE, efficacy was 59.8%, with variability according to the center between 31.7 to 100%. The recruitment efficacy of patients with secondary or idiopathic PE was 42.1% vs. 59.8%, respectively (p < 0.001). CONCLUSIONS: A wide percentage of patients can pass up from prospectives studies. The results of this study try to make us think, that we need more strategies to get a good recruit of consecutive patients, especially in those studies where is essential collect all patients

BDNF and NGF Signalling in Early Phases of Psychosis: Relationship With Inflammation and Response to Antipsychotics After 1 Year.

Previous studies have indicated systemic deregulation of the proinflammatory or anti-inflammatory balance in individuals with first-episode psychosis (FEP) that persists 12 months later. To identify potential risk/protective factors and associations with symptom severity, we assessed possible changes in plasma levels of neurotrophins (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) and their receptors in peripheral blood mononuclear cells (PBMCs). Expression of the 2 forms of BDNF receptors (active TrkB-FL and inactiveTrkB-T1) in PBMCs of FEP patients changed over time, TrkB-FL expression increasing by 1 year after diagnosis, while TrkB-T1 expression decreased. The TrkB-FL/TrkB-T1 ratio (hereafter FL/T1 ratio) increased during follow-up in the nonaffective psychosis group only, suggesting different underlying pathophysiological mechanisms in subgroups of FEP patients. Further, the expression of the main NGF receptor, TrkA, generally increased in patients at follow-up. After adjusting for potential confounders, baseline levels of inducible isoforms of nitric oxide synthase, cyclooxygenase, and nuclear transcription factor were significantly associated with the FL/T1 ratio, suggesting that more inflammation is associated with higher values of this ratio. Interestingly, the FL/T1 ratio might have a role as a predictor of functioning, a regression model of functioning at 1 year suggesting that the effect of the FL/T1 ratio at baseline on functioning at 1 year depended on whether patients were treated with antipsychotics. These findings may have translational relevance; specifically, it might be useful to assess the expression of TrkB receptor isoforms before initiating antipsychotic treatment in FEPs.

CGP37157, an inhibitor of the mitochondrial Na+/Ca2+ exchanger, protects neurons from excitotoxicity by blocking voltage-gated Ca2+ channels.

Inhibition of the mitochondrial Na(+)/Ca(2+) exchanger (NCLX) by CGP37157 is protective in models of neuronal injury that involve disruption of intracellular Ca(2+) homeostasis. However, the Ca(2+) signaling pathways and stores underlying neuroprotection by that inhibitor are not well defined. In the present study, we analyzed how intracellular Ca(2+) levels are modulated by CGP37157 (10 µM) during NMDA insults in primary cultures of rat cortical neurons. We initially assessed the presence of NCLX in mitochondria of cultured neurons by immunolabeling, and subsequently, we analyzed the effects of CGP37157 on neuronal Ca(2+) homeostasis using cameleon-based mitochondrial Ca(2+) and cytosolic Ca(2+) ([Ca(2+)]i) live imaging. We observed that NCLX-driven mitochondrial Ca(2+) exchange occurs in cortical neurons under basal conditions as CGP37157 induced a decrease in [Ca(2)]i concomitant with a Ca(2+) accumulation inside the mitochondria. In turn, CGP37157 also inhibited mitochondrial Ca(2+) efflux after the stimulation of acetylcholine receptors. In contrast, CGP37157 strongly prevented depolarization-induced [Ca(2+)]i increase by blocking voltage-gated Ca(2+) channels (VGCCs), whereas it did not induce depletion of ER Ca(2+) stores. Moreover, mitochondrial Ca(2+) overload was reduced as a consequence of diminished Ca(2+) entry through VGCCs. The decrease in cytosolic and mitochondrial Ca(2+) overload by CGP37157 resulted in a reduction of excitotoxic mitochondrial damage, characterized here by a reduction in mitochondrial membrane depolarization, oxidative stress and calpain activation. In summary, our results provide evidence that during excitotoxicity CGP37157 modulates cytosolic and mitochondrial Ca(2+) dynamics that leads to attenuation of NMDA-induced mitochondrial dysfunction and neuronal cell death by blocking VGCCs.

Seguimiento del paciente con embolismo pulmonar: complicaciones y evolución / Follow-up of patients with pulmonary embolism: Complications and developments

Objetivo: Analizar la supervivencia a 2 años de pacientes consecutivos diagnosticados de EP, las recidivas trombóticas y los eventos hemorrágicos. Pacientes y Método: Estudio de cohorte de pacientes diagnosticados de forma consecutiva de EP seguidos durante dos años, analizando la supervivencia y las complicaciones a largo plazo (recidivas y hemorragia).Resultados: 165 pacientes diagnosticados de forma consecutiva de EP, 17 fallecieron durante el evento agudo. Se incluyeron en el estudio 148 pacientes, 50% varones, con una edad de 64.17 +/- 17.23 años. Durante el seguimiento fallecieron 34 pacientes (23%), se perdieron 5 (3.4%), recidivaron 13 (8.8%) y 16 (10.8%) presentaron sangrado. Las recidivas se presentaron como EP (n=6), trombosis venosa profunda (TVP) (n=6) o EP con TVP (n=1). Seis de los pacientes con recidiva se presentaron inicialmente como EP idiopático, y 7 de ellos como EP secundario. De los 13 pacientes que presentaron recidiva, 2 fallecieron a los 2 años de seguimiento, y ninguno como consecuencia de la recidiva. En cuanto al sangrado, éste se produjo a los 3.23 meses (rango 28.17 meses) del evento agudo; el 37.5% fueron sangrados mayores. La causa de muerte más frecuente fue el cáncer. La incidencia acumulada de mortalidad fue del 19.2% al año y del 29.6% a los dos años. Las variables asociadas a una menor supervivencia fueron una creatinina mayor de 2 mg/dl, la existencia de neoplasia previa, la demencia y la dislipemia. Conclusiones: el seguimiento de los pacientes con EP debe ser más estrecho en los primeros meses, ya que en este periodo de tiempo se producen las complicaciones de la enfermedad (muerte, recidivas y hemorragias) (AU)

Objective: To analyze the survival after two years in consecutive patients diagnosed of pulmonary embolism (PE), thrombotic relapse and episodes of bleeding. Patients and Method: Cohort study of patients diagnosed consecutively of PE, with a two-year follow-up, analyzing survival and long-term complications (relapse and bleeding). Results: 165 consecutive patients diagnosed of PE were initially included in the study., Seventeen died during an acute event, .and 148 patients were finally included in the study, of which 50% were males, with mean age = 64.17 + 17.23 years. During follow-up, 34 patients died (23%), 5 were lost (3.4%), 13 relapsed (8.8%) and 16 (10.8%) suffered bleeding. Relapse appeared as PE (n=6), deep vein thrombosis (DVT) (n=6) or PE with DVT (n=1). Six of the patients with relapse initially appeared as idiopathic PE and seven of them as secondary PE. Of the 13 patients with relapse, 2 died after the two-year follow-up and none as a consequence of the relapse. In terms of bleeding, this event appeared 3.23 month (average, extreme range= 28.17 months) after an acute event; 37.5% were major bleeding events. The most frequent cause of death was cancer. The accumulated mortality incidence was 19.2% after one year and 29.6% after two years. The variables associated with less survival were serum creatinine greater than 2 mg/dl, the existence of prior neoplasm, dementia and dyslipidemia. Conclusions: Follow-up of PE patients must be strict during the first few months, as this is when the complications appear (death, relapse and hemorrhaging) (AU)

1-42 ß-amyloid peptide requires PDK1/nPKC/Rac 1 pathway to induce neuronal death.

1-42 ß-Amyloid (Aß(1-42)) peptide is a key molecule involved in the development of Alzheimer's disease. Some of its effects are manifested at the neuronal morphological level. These morphological changes involve loss of neurites due to cytoskeleton alterations. However, the mechanism of Aß(1-42) peptide activation of the neurodegenerative program is still poorly understood. Here, Aß(1-42) peptide-induced transduction of cellular death signals through the phosphatidylinositol 3-kinase (PI3K)/phosphoinositol-dependent kinase (PDK)/novel protein kinase C (nPKC)/Rac 1 axis is described. Furthermore, pharmacological inhibition of PDK1 and nPKC activities blocks Rac 1 activation and neuronal cell death. Our results provide insights into an unsuspected connection between PDK1, nPKCs and Rac 1 in the same signal-transduction pathway and points out nPKCs and Rac 1 as potential therapeutic targets to block the toxic effects of Aß(1-42) peptide in neurons.

Oligodendrocyte differentiation from adult multipotent stem cells is modulated by glutamate.

We used multipotent stem cells (MSCs) derived from the young rat subventricular zone (SVZ) to study the effects of glutamate in oligodendrocyte maturation. Glutamate stimulated oligodendrocyte differentiation from SVZ-derived MSCs through the activation of specific N-methyl-D-aspartate (NMDA) receptor subunits. The effect of glutamate and NMDA on oligodendrocyte differentiation was evident in both the number of newly generated oligodendrocytes and their morphology. In addition, the levels of NMDAR1 and NMDAR2A protein increased during differentiation, whereas NMDAR2B and NMDAR3 protein levels decreased, suggesting differential expression of NMDA receptor subunits during maturation. Microfluorimetry showed that the activation of NMDA receptors during oligodendrocyte differentiation elevated cytosolic calcium levels and promoted myelination in cocultures with neurons. Moreover, we observed that stimulation of MSCs by NMDA receptors induced the generation of reactive oxygen species (ROS), which were negatively modulated by the NADPH inhibitor apocynin, and that the levels of ROS correlated with the degree of differentiation. Taken together, these findings suggest that ROS generated by NADPH oxidase by the activation of NMDA receptors promotes the maturation of oligodendrocytes and favors myelination.

A cytokine gene screen uncovers SOCS1 as genetic risk factor for multiple sclerosis.

Cytokine and cytokine receptor genes, including IL2RA, IL7R and IL12A, are known risk factors for multiple sclerosis (MS). Excitotoxic oligodendroglial death mediated by glutamate receptors contributes to demyelinating reactions. In the present study, we screened 368 single-nucleotide polymorphisms (SNPs) in 55 genes or gene clusters coding for cytokines, cytokine receptors, suppressors of cytokine signaling (SOCS), complement factors and glutamate receptors for association with MS in a Spanish-Basque resident population. Top-scoring SNPs were found within or nearby the genes coding for SOCS-1 (P=0.0005), interleukin-28 receptor, alpha chain (P=0.0008), oncostatin M receptor (P=0.002) and interleukin-22 receptor, alpha 2 (IL22RA2; P=0.003). The SOCS1 rs243324 variant was validated as risk factor for MS in a separate cohort of 3919 MS patients and 4003 controls (combined Cochran-Mantel-Haenszel P=0.00006; odds ratio (OR)=1.13; 95% confidence interval (CI)=1.07-1.20). In addition, the T allele of rs243324 was consistently increased in relapsing-remitting/secondary progressive versus primary-progressive MS patients, in each of the six data sets used in this study (P(CMH)=0.0096; OR=1.24; 95% CI 1.05-1.46). The association with SOCS1 appears independent from the chr16MS risk locus CLEC16A.

Intracellular Ca2+ release through ryanodine receptors contributes to AMPA receptor-mediated mitochondrial dysfunction and ER stress in oligodendrocytes.

Overactivation of ionotropic glutamate receptors in oligodendrocytes induces cytosolic Ca(2+) overload and excitotoxic death, a process that contributes to demyelination and multiple sclerosis. Excitotoxic insults cause well-characterized mitochondrial alterations and endoplasmic reticulum (ER) dysfunction, which is not fully understood. In this study, we analyzed the contribution of ER-Ca(2+) release through ryanodine receptors (RyRs) and inositol triphosphate receptors (IP(3)Rs) to excitotoxicity in oligodendrocytes in vitro. First, we observed that oligodendrocytes express all previously characterized RyRs and IP(3)Rs. Blockade of Ca(2+)-induced Ca(2+) release by TMB-8 following α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor-mediated insults attenuated both oligodendrocyte death and cytosolic Ca(2+) overload. In turn, RyR inhibition by ryanodine reduced as well the Ca(2+) overload whereas IP(3)R inhibition was ineffective. Furthermore, AMPA-triggered mitochondrial membrane depolarization, oxidative stress and activation of caspase-3, which in all instances was diminished by RyR inhibition. In addition, we observed that AMPA induced an ER stress response as revealed by α subunit of the eukaryotic initiation factor 2α phosphorylation, overexpression of GRP chaperones and RyR-dependent cleavage of caspase-12. Finally, attenuating ER stress with salubrinal protected oligodendrocytes from AMPA excitotoxicity. Together, these results show that Ca(2+) release through RyRs contributes to cytosolic Ca(2+) overload, mitochondrial dysfunction, ER stress and cell death following AMPA receptor-mediated excitotoxicity in oligodendrocytes.

Análisis clínico-epidemiológico de pacientes consecutivos con tromboembolismo pulmonar / Clinical-epidemiological analysis of consecutive patients with pulmonary thromboembolism

INTRODUCCIÓN: El tromboembolismo pulmonar (TEP) constituye un problema sanitario de gran trascendencia debido a su elevada morbimortalidad. La enfermedad tromboembólica venosa (ETV) ocasiona unas 300.000 hospitalizaciones al año, con una incidencia del 0,5 al 2,5% entre los pacientes ingresados por patología médica y del 0,1 al 0,6% de los ingresados por causa quirúrgica. La prevalencia entre los ingresados es aproximadamente del 1%.OBJETIVO: Estudiar las características de los pacientes ingresados por TEP en nuestro medio hospitalario a fin de poder valorar la epidemiología, los factores de riesgo y la evolución durante el periodo agudo. PACIENTES Y MÉTODO: Se estudiaron a todos los pacientes ingresados y diagnosticados de TEP en los Hospitales Universitarios Virgen del Rocío de Sevilla en el periodo comprendido desde febrero de 2003 hasta septiembre del 2004. Se realizó una sistemática recogida de datos clínicos, diagnósticos, y evolutivos hasta el alta hospitalaria. RESULTADOS: Durante 19 meses consecutivos un total de456 pacientes ingresaron en nuestra área hospitalaria por sospecha de TEP. De estos sólo en 165 casos (36%) se confirmó dicho diagnóstico. Ochenta y dos (49.7%) eran mujeres y ochenta y tres hombres (50.3%). La edad media de fue de 64.47±16.77. El factor de riesgo para la ETV presente con más frecuencia fue la inmovilización secundaria. Los síntomas de presentación más frecuente fueron la disnea y el dolor torácico. El electrocardiograma fue normal en la mayoría de los pacientes [N=61(37%)] El derrame pleural fue el hallazgo radiológico más frecuente (37.6%). El signo más prevalente en la ecocardiografía fue la presencia de insuficiencia tricuspíde a (50.3%). La mortalidad en nuestra serie fue del 10.3%. CONCLUSIONES: El incremento en la edad de nuestros pacientes, los factores de riesgo asociados a la enfermedad tromboembólica, y las nuevas herramientas pronosticas, pueden facilitarnos el manejo de esta enfermedad que escasamente ha variado su morbimortalidad a pesar de los avances médicos

INTRODUCTION: Pulmonary thromboembolism (PTE) constitutes a health problem of great importance due to its high morbimortality. Venous thromboembolic disease (VTE) causes 300,000 hospitalizations a year, with an incidence from 0.5 to 2.5%among the patients admitted for medical pathology and from 0.1 to0.6% of those admitted for surgical causes. The prevalence among admissions is approximately 1%.OBJECTIVE: To study the characteristics of the patients admitted for PTE in our hospital area in order to be able to evaluate the epidemiology, the risk factors and the evolution during the acute period. PATIENTS AND METHOD: We studied all patients who were admitted to the University Hospitals Virgen del Rocio of Seville in the period included from February 2003 to September 2004 and diagnosed with PTE. Clinical data, diagnoses, and evolutions were systematically collected until the hospital discharge. Troponin and BNP (brain natriuretic peptide) levels in blood were determined, and echocardiography was performed, in the first 48 h after admission. RESULTS: During 19 consecutive months a total of 456patients entered our hospital area with suspicion of PTE. Of these, this diagnosis was confirmed in only 165 cases (36%). Eighty two(49.7%) were women and eighty three (50.3%) were men. The average age was 64.47±16.77. The risk factor for VTE presented with more frequency was immobilisation secondary to admission. The symptoms presented more frequently were dyspnoea and thoracic pain. The electrocardiogram was normal in most of the patients [N=61 (37%). Pleural effusion was the more frequent radiological finding (37.6%). The more prevalent sign in the echocardiography was the presence of tricuspid insufficiency (50.3%). Mortality in our series was 10.3%.CONCLUSIONS: The increase in the age of our patients, the risk factors associated to thromboembolic disease mainly in hospitalized patients, and the new prognostic tools, can facilitate our handling of this disease that has barely varied its morbimortality in spite of the technological advances

Glia: the fulcrum of brain diseases.

Neuroglia represented by astrocytes, oligodendrocytes and microglial cells provide for numerous vital functions. Glial cells shape the micro-architecture of the brain matter; they are involved in information transfer by virtue of numerous plasmalemmal receptors and channels; they receive synaptic inputs; they are able to release 'glio'transmitters and produce long-range information exchange; finally they act as pluripotent neural precursors and some of them can even act as stem cells, which provide for adult neurogenesis. Recent advances in gliology emphasised the role of glia in the progression and handling of the insults to the nervous system. The brain pathology, is, to a very great extent, a pathology of glia, which, when falling to function properly, determines the degree of neuronal death, the outcome and the scale of neurological deficit. Glial cells are central in providing for brain homeostasis. As a result glia appears as a brain warden, and as such it is intrinsically endowed with two opposite features: it protects the nervous tissue as long as it can, but it also can rapidly assume the guise of a natural killer, trying to eliminate and seal the damaged area, to save the whole at the expense of the part.

Inhibition of cyclin-dependent kinases is neuroprotective in 1-methyl-4-phenylpyridinium-induced apoptosis in neurons.

The biochemical pathways involved in neuronal cell death in Parkinson's disease are not completely characterized. Mitochondrial dysfunction, specifically alteration of the mitochondrial complex I, is the primary target of the parkinsonian neurotoxin 1-methyl-4-phenylpyridinium (MPP+) induced apoptosis in neurons. In the present study, we examine the role of caspase-dependent and -independent routes in MPP+-induced apoptosis in rat cerebellar granule neurons (CGNs). We show a distinct increase in the expression of the cell cycle proteins cyclin D, cyclin E, cdk2, cdk4 and the transcription factor E2F-1 following a MPP+ treatment of CGNs. Flavopiridol (FLAV), a broad inhibitor of cyclin-dependent kinases (CDKs), attenuated the neurotoxic effects of MPP+ and significantly attenuates apoptosis mediated by MPP+ 200 microM. Likewise, the antioxidant vitamin E (vit E) increases neuronal cell viability and attenuates apoptosis induced by MPP+. Moreover, the expression levels of cyclin D and E2F-1 induced by this parkinsonian neurotoxin were also attenuated by vit E. Since, the broad-spectrum caspase inhibitor zVAD-fmk did not attenuate MPP+-induced apoptosis in CGNs, our data provide a caspase-independent mechanism mediated by neuronal reentry in the cell cycle and increased expression of the pro-apoptotic transcription factor E2F-1. Our results also suggest a potential role of oxidative stress in neuronal reentry in the cell cycle mediated by MPP+. Finally, our data further support the therapeutic potential of flavopiridol, for the treatment of Parkinson's disease.

Excitotoxic insults to the optic nerve alter visual evoked potentials.

Excitotoxic oligodendroglial death is one of the mechanisms which has been proposed to underlie demyelinating diseases of the CNS. We describe here functional consequences of excitotoxic lesions to the rabbit optic nerve by studying the visual evoked potentials (VEPs) measured in the visual cortex. Nerves were slowly infused with the excitotoxin kainate a subcutaneously implanted osmotic pump which delivered the toxin through a cannula onto the optic nerve. Records of VEPs were obtained before pump implantation and at 1, 3 and 7 days post-implantation, and weekly evaluated thereafter for up to 4 months. We observed that the VEPs generated by light stimuli progressively changed in both amplitude and profile after the lesion as well as in comparison to those generated in control animals infused with vehicle. Histological examination of the damage caused by the excitotoxic insult showed that large areas of the optic nerve were demyelinated and their axons distorted. These observations were confirmed and extended by immunohistochemical analyses using markers to neurofilaments, myelin basic protein and the oligodendrocyte marker APC. The results of the present paper indicate that the consequences of excitotoxicity in the optic nerve share functional and morphological alterations which are found in demyelinating disorders. In addition, this experimental paradigm may be useful to evaluate the functional recovery of demyelinated optic nerves following various repair strategies.

Differential expression of calcium channel subtypes in the bovine adrenal medulla.

This study aimed at determining the distribution and expression levels of different subtypes of Ca(2+) channels in the bovine adrenal medulla, and whether individual subtypes were more abundant in chromaffin cells exhibiting an adrenergic or a noradrenergic phenotype. In situ hybridization using riboprobes specific for the pore-forming Ca(2+) channel alpha(1D) (L-type channel), alpha(1B) (N-type channel), and alpha(1A) (P/Q-type channel) subunits of bovine chromaffin cells showed a broad distribution of the three transcripts in adrenal medulla tissue. However, a tissue-specific expression pattern of individual subunits was found; whereas alpha(1B) mRNA was homogeneously distributed throughout the medulla, alpha(1D) and alpha(1A) transcripts were present at higher densities in the internal medullary area, far away from the adrenal cortex. These results were corroborated by comparative analysis of the alpha(1B), alpha(1D), and alpha(1A) products amplified by RT-PCR from total RNA extracted from small pieces of tissue dissected out from external or internal medullary areas. Interestingly, immunohistochemical experiments performed in adrenal gland sections, using antidopamine-beta-hydroxylase and anti-phenylethanolamine-N-methyltransferase antibodies, indicated a higher density of noradrenergic over adrenergic chromaffin cells in the internal medullary region. These results provide direct evidence in favor of a heterogeneous distribution of Ca(2+) channel subtypes in the adrenal medulla, in agreement with previous functional data showing that blockade of the high K+ -elicited responses by dihydropyridines was greater in noradrenergic than in adrenergic chromaffin cells. These differences may be relevant for the differential release regulation of each catecholamine under physiological and pathophysiological conditions.

Angiotensin receptor-like immunoreactivity in adult brain white matter astrocytes and oligodendrocytes.

Most of the physiological effects of brain angiotensins are currently believed to be mediated by angiotensin receptors located principally on neurons. However, numerous studies in vitro have demonstrated the presence of functional angiotensin receptors on brain astrocytes, raising the possibility that glial cells may also participate in mediating the effects of the central renin-angiotensin system. Nevertheless, it is uncertain whether these cells in situ express angiotensin receptors, raising questions about the physiological significance of results observed in cell cultures. We have examined the distribution of angiotensin receptor-like immunoreactivity in glial cells in white matter tracts in the adult CNS, using a panel of antisera to the AT1 and AT2 angiotensin receptors. Antiserum preadsorption and/or Western blot demonstrated the specificity of the antisera in brain tissue. In immunohistochemical experiments, the AT1 antisera selectively labeled AT1-expressing neurons in the piriform cortex, whereas the AT2 antiserum stained cells in the trigeminal motor nucleus, these being nuclei known to express AT1 and AT2 receptors, respectively. Using double-label immunohistochemistry, we observed AT1- and AT2-immunoreactive astrocytes and oligodendrocytes in white matter tracts, which include the rat cerebellar white matter, periventricular white matter, and optic nerve, in addition to the bovine corpus callosum and human subcortical white matter. In contrast, astrocytes in the gray matter region of the cerebral cortex were not found to be angiotensin receptor-like immunoreactive. These results demonstrate the presence of AT1 and/or AT2 angiotensin receptor-like immunoreactivity in brain white matter macroglial cells in situ and support the idea that glial cells may play a more important role in the central renin-angiotensin system than previously thought.