RESUMEN
The aim of this study was to determine the effect of prolactin (PRL) on intracellular calcium (Ca2+) concentration and its neuroprotective role in a model of kainic acid (KA) excitotoxicity in primary cultures of hippocampal neurons. Cell viability and intracellular Ca2+ concentrations were determined by MTT and Fura-2 assays, respectively, either after induction by KA as an agonist or after treatment with NBQX antagonist alone or in combination with PRL administration. Expression of ionotropic glutamatergic receptors (iGluRs) subunits in neuronal cells was determined by RT-qPCR. Dose-response treatments with KA or glutamate (Glu), the latter used as endogenous agonist control, induced a significant increase in neuronal intracellular Ca2+ concentration followed by a significant decrease in hippocampal neuronal viability. Administration of PRL induced a significant increase in neuronal viability after treatment with KA. Furthermore, administration of PRL decreased intracellular Ca2+ concentrations induced by KA treatment. Independent administration of the AMPAR-KAR antagonist reversed cell death and reduced intracellular Ca2+ concentration in a similar manner as PRL. Additionally, mRNA expression of AMPAR, KAR and NMDAR subtypes were detected in hippocampal neurons; however, no significant changes in iGluRs subunit expression were observed due to excitotoxicity or PRL treatment. The results suggest that PRL inhibits the increase in intracellular Ca2+ concentration induced by KA, leading to neuroprotection.
Asunto(s)
Ácido Kaínico , Prolactina , Prolactina/farmacología , Ácido Kaínico/toxicidad , Neuroprotección , Hipocampo/metabolismo , Neuronas/metabolismoRESUMEN
OBJECTIVES: Shigella sonnei is a globally important diarrhoeal pathogen tracked through the surveillance network PulseNet Latin America and Caribbean (PNLA&C), which participates in PulseNet International. PNLA&C laboratories use common molecular techniques to track pathogens causing foodborne illness. We aimed to demonstrate the possibility and advantages of transitioning to whole genome sequencing (WGS) for surveillance within existing networks across a continent where S. sonnei is endemic. METHODS: We applied WGS to representative archive isolates of S. sonnei (n = 323) from laboratories in nine PNLA&C countries to generate a regional phylogenomic reference for S. sonnei and put this in the global context. We used this reference to contextualise 16 S. sonnei from three Argentinian outbreaks, using locally generated sequence data. Assembled genome sequences were used to predict antimicrobial resistance (AMR) phenotypes and identify AMR determinants. RESULTS: S. sonnei isolates clustered in five Latin American sublineages in the global phylogeny, with many (46%, 149 of 323) belonging to previously undescribed sublineages. Predicted multidrug resistance was common (77%, 249 of 323), and clinically relevant differences in AMR were found among sublineages. The regional overview showed that Argentinian outbreak isolates belonged to distinct sublineages and had different epidemiologic origins. CONCLUSIONS: Latin America contains novel genetic diversity of S. sonnei that is relevant on a global scale and commonly exhibits multidrug resistance. Retrospective passive surveillance with WGS has utility for informing treatment, identifying regionally epidemic sublineages and providing a framework for interpretation of prospective, locally sequenced outbreaks.
Asunto(s)
Disentería Bacilar , Enfermedades Transmitidas por los Alimentos , Shigella sonnei/genética , Región del Caribe/epidemiología , ADN Bacteriano/análisis , ADN Bacteriano/genética , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/estadística & datos numéricos , Farmacorresistencia Bacteriana , Disentería Bacilar/epidemiología , Disentería Bacilar/microbiología , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , América Latina/epidemiología , Vigilancia en Salud Pública , Estudios Retrospectivos , Shigella sonnei/efectos de los fármacos , Secuenciación Completa del GenomaRESUMEN
OBJECTIVE: Neuromusculoskeletal models involve many subject-specific physiological parameters that need to be adjusted to adequately represent muscle properties. Traditionally, neuromusculoskeletal models have been calibrated with a forward-inverse dynamic optimization which is time-consuming and unfeasible for rehabilitation therapy. Non self-calibration algorithms have been applied to these models. To the best of our knowledge, the algorithm proposed in this work is the first on-line calibration algorithm for muscle models that allows a generic model to be adjusted to different subjects in a few steps. APPROACH: In this paper we propose a reformulation of the traditional muscle models that is able to sequentially estimate the kinetics (net joint moments), and also its full self-calibration (subject-specific internal parameters of the muscle from a set of arbitrary uncalibrated data), based on the unscented Kalman filter. The nonlinearity of the model as well as its calibration problem have obliged us to adopt the sum of Gaussians filter suitable for nonlinear systems. MAIN RESULTS: This sequential Bayesian self-calibration algorithm achieves a complete muscle model calibration using as input only a dataset of uncalibrated sEMG and kinematics data. The approach is validated experimentally using data from the upper limbs of 21 subjects. SIGNIFICANCE: The results show the feasibility of neuromusculoskeletal model self-calibration. This study will contribute to a better understanding of the generalization of muscle models for subject-specific rehabilitation therapies. Moreover, this work is very promising for rehabilitation devices such as electromyography-driven exoskeletons or prostheses.
Asunto(s)
Articulación del Codo/fisiología , Electromiografía/métodos , Modelos Neurológicos , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Rango del Movimiento Articular/fisiología , Teorema de Bayes , Simulación por Computador , Femenino , Humanos , Masculino , Reconocimiento de Normas Patrones Automatizadas/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estrés Mecánico , Torque , Adulto JovenRESUMEN
Claudins participate in tissue barrier function. The loss of this barrier is associated to metalloproteases-related extracellular matrix and basal membranes degradation. Claudin-1 is a pro-MMP-2 activator and claudin-6 transfected AGS (AGS-Cld6) cells are highly invasive. Our aim was to determine if claudin-6 was direct or indirectly associated with MMP-2 activation and cell invasiveness. Cytofluorometry, cell fractioning, immunoprecipitation, gelatin-zymography, cell migration and invasiveness assays were performed, claudin-2, -6, -7 and -9 transfected AGS cells, anti-MMP-2, -9 and -14, anti-claudins specific antibodies and claudin-1 small interfering RNA were used. The results showed a significant (p<0.001) overexpression of claudin-1 in AGS-Cld6 cell membranes. A strong MMP-2 activity was identified in culture supernatants of AGS-Cld6. Claudin-1 co-localized with MMP-2 and MMP-14; interestingly a significant increase in cell membrane and cytosol MMP-14 expression was detected in AGS-Cld6 cells (p<0.05). Silencing of claudin-1 in AGS-Cld6 cells showed a 60% MMP-2 activity decrease in culture supernatants and a significant decrease (p<0.05) in cell migration and invasiveness. Our results suggest that claudin-6 induces MMP-2 activation through claudin-1 membrane expression, which in turn promotes cell migration and invasiveness.
Asunto(s)
Adenocarcinoma/metabolismo , Movimiento Celular/fisiología , Claudina-1/metabolismo , Claudinas/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/patología , Línea Celular Tumoral , Membrana Celular/metabolismo , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Invasividad Neoplásica , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Uniones Estrechas/metabolismoRESUMEN
Adoptive immunotherapy requires the isolation of CD8+ T cells specific for tumor-associated antigens, their expansion in vitro and their transfusion to the patient to mediate a therapeutic effect. MUC1 is an important adenocarcinoma antigen immunogenic for T cells. The MUC1-derived SAPDTRPA (MUC1-8-mer) peptide is a potent epitope recognized by CD8+ T cells in murine models. Likewise, the T2 cell line has been used as an antigen-presenting cell to activate CD8+ T cells, but so far MUC1 has not been assessed in this context. We evaluated whether the MUC1-8-mer peptide can be presented by T2 cells to expand CD25+CD8+ T cells isolated from HLA-A2+ lung adenocarcinoma patients with stage III or IV tumors. The results showed that MUC1-8-mer peptide-loaded T2 cells activated CD8+ T cells from cancer HLA-A2+ patients when anti-CD2, anti-CD28 antibodies and IL-2 were added. The percentage of CD25+CD8+ T cells was 3-fold higher than those in the non-stimulated cells (P=0.018). HLA-A2+ patient cells showed a significant difference (2.3-fold higher) in activation status than HLA-A2+ healthy control cells (P=0.04). Moreover, 77.6% of MUC1-8-mer peptide-specific CD8+ T cells proliferated following a second stimulation with MUC1-8-mer peptide-loaded T2 cells after 10 days of cell culture. There were significant differences in the percentage of basal CD25+CD8+ T cells in relation to the cancer stage; this difference disappeared after MUC1-8-mer peptide stimulation. In conclusion, expansion of CD25+CD8+ T cells by MUC1-8 peptide-loaded T2 cells plus costimulatory signals via CD2, CD28 and IL-2 can be useful in adoptive immunotherapy.
Asunto(s)
Linfocitos T CD8-positivos/citología , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Epítopos de Linfocito T/metabolismo , Neoplasias Pulmonares/inmunología , Mucina-1/inmunología , Linfocitos T Citotóxicos/inmunología , Adulto , Anciano , Linfocitos T CD8-positivos/inmunología , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular , Proliferación Celular , Femenino , Antígeno HLA-A2/metabolismo , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Linfocitos T Citotóxicos/metabolismo , Células Tumorales CultivadasRESUMEN
Several studies suggest that ATP and related nucleotides play a role in the pathophysiology of asthma. However, the functionality of ectonucleotidases in this disease has been scantly investigated. We studied total ectonucleotidase activity in leukocytes from patients suffering from asthma exacerbation and explored the expression of E-NTPDase 1, 2, 3, and 8, and E-NPP1, 2, and 3, in their polymorphonuclear cells by immunofluorescence and qPCR. Leukocytes from patients with mild or moderate asthma exacerbation had similar ectonucleotidase activity than leukocytes from healthy subjects, while in patients with severe asthma exacerbation, this activity was lower. Of the ectonucleotidases studied, only E-NPP1 displayed diminished immunofluorescence and a significant decrease in its mRNA expression, both in patients with severe asthma exacerbation. This reduced E-NPP1 expression could be responsible for increased amounts of ATP or other nucleotides, capable of worsening asthma exacerbation, and warranting further investigation.
Asunto(s)
Asma/genética , Regulación de la Expresión Génica , Leucocitos/metabolismo , Hidrolasas Diéster Fosfóricas/genética , Pirofosfatasas/genética , Adenosina Trifosfato/metabolismo , Asma/diagnóstico , Asma/metabolismo , Progresión de la Enfermedad , Técnica del Anticuerpo Fluorescente , Humanos , Hidrolasas Diéster Fosfóricas/metabolismo , Pirofosfatasas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
In this work we have studied different indicators of muscle fatigue from the electrical signal produced by the muscles when contract (sEMG or EMG: surface electromyography): Mean Frequency of the power spectrum (MNF), Median Frequency (Fmed), Dimitrov Spectral Index (FInsm5), Root Mean Square (RMS), and Zerocrossing (ZC). The most reliable features are selected to develop a detection algorithm that estimates muscle fatigue. The approach used in the algorithm is probabilistic and is based on the technique of Gaussian Mixture Model (GMM). The system is divided into two stages: training and validation. During training, the algorithm learns the distribution of data regarding fatigue evolution; after that, the algorithm is validated with data that have not been used to train. Therefore, two experimental sessions have been performed with 6 healthy subjects for biceps.
Asunto(s)
Fatiga Muscular , Algoritmos , Brazo , Electromiografía , Humanos , Contracción Muscular , Músculo EsqueléticoRESUMEN
Rehabilitation exercises cause fatigue because tasks are repetitive. Therefore, inevitable human motion performance changes occur during the therapy. Although traditionally fatigue is considered an event that occurs in the musculoskeletal level, this paper studies whether fatigue can be regarded as context that influences lower-dimensional motor control organization and coordination at neural level. Non Negative Factorization Matrix (NNFM) and Detrended Fluctuations Analysis (DFA) are the tools used to analyze the changes in the coordination of motor function when someone is affected by fatigue. The study establishes that synergies remain fairly stable with the onset of fatigue, but the fatigue affects the dynamical coordination understood as a cognitive process. These results have been validated with 9 healthy subjects for three representative exercises for upper limb: biceps, triceps and deltoid.
Asunto(s)
Brazo/fisiología , Fatiga Muscular/fisiología , Extremidad Superior/fisiología , Adulto , Electromiografía , Ejercicio Físico , Femenino , Humanos , Masculino , Músculo Esquelético/fisiología , Dinámicas no LinealesRESUMEN
Airway smooth muscle (ASM) membrane depolarization through KCl opens L-type voltage dependent Ca2+ channels (Ca(v)1.2); its opening was considered the cause of KCl contraction. This substance is used to bypass intracellular second messenger pathways. It is now clear that KCl also activates RhoA/Rho kinase (ROCK) pathway. ROCK isoforms are characterized as ROCK1 and ROCK2. Because ROCK1 seems the most abundant isotype in lung, we studied its participation in KCl stimulated bovine ASM. With methyl-beta-cyclodextrin (MbetaCD) we disrupted caveolae, a membrane compartment considered as the RhoA/ROCK assembly site, and found that KCl contraction was reduced to the same extent (~26%) as Y-27632 (ROCK inhibitor) treated tissues. We confirmed that KCl induces ROCK activation and this effect was annulled by Y-27632 or MbetaCD. In isolated plasmalemma, ROCK1 was localized in non-caveolar membrane fractions in Western blots from control tissues, but it transferred to caveolae in samples from tissues stimulated with KCl. Ca(v)1.2 was found at the non-caveolar membrane fractions in control and MbetaCD treated tissues. In MbetaCD treated tissues stimulated with KCl, contraction was abolished by nifedipine; only the response to Ca(v)1.2 opening remained as the ROCK component disappeared. Our results show that, in ASM, the KCl contraction involves the translocation of ROCK1 from non-caveolar to caveolar regions and that the proper physiological response depends on this translocation.
Asunto(s)
Caveolas/metabolismo , Contracción Muscular/fisiología , Músculo Liso/metabolismo , Cloruro de Potasio/farmacología , Tráquea/metabolismo , Quinasas Asociadas a rho/metabolismo , Animales , Bovinos , Caveolas/efectos de los fármacos , Contracción Muscular/efectos de los fármacos , Relajantes Musculares Centrales/farmacología , Músculo Liso/efectos de los fármacos , Técnicas de Cultivo de Órganos , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/fisiología , Tráquea/efectos de los fármacosRESUMEN
The three most common Cys-loop receptors expressed by myenteric neurons are nACh, 5-HT3 and GABAA . To investigate the function of these proteins researchers have used channel inhibitors such as hexamethonium (antagonist of nACh receptors), ondansetron (antagonist of 5-HT3 receptors), picrotoxin and bicuculline (both antagonists of GABAA receptors). The aim of this study was to investigate the specificity of these inhibitors on Cys-loop receptors of primary cultured neurons obtained from the guinea-pig small intestine. The whole-cell configuration of the patch clamp techniques was used to record membrane currents induced by ACh (IACh ), 5-HT (I5-HT ) and GABA (IGABA ) in the absence and the presence of various concentrations of hexamethonium, ondansetron, picrotoxin or bicuculline. The three Cys-loop receptors present in enteric neurons are expressed independently and they do not cross-desensitized. Hexamethonium inhibited IACh without affecting I5-HT and IGABA . Ondansetron inhibited I5-HT and also IACh but did not affect IGABA . Picrotoxin and bicuculline inhibited I5-HT , IACh and IGABA with different potency, being the lowest potency on 5-HT3 receptors. All these inhibitory effects were concentration dependent and reversible. Our observations showed that except for hexamethonium, all other inhibitors used here show different degrees of selectivity, which has to be considered when these antagonists are used in experimental studies aimed to investigate the functions of these receptors. In particular, in tissues expressing nACh receptors because these are the targets of all other inhibitors used here. The low potency of picrotoxin and bicuculline to inhibit 5-HT3 receptors suggests that these receptors are heteromeric proteins.
Asunto(s)
Antagonistas Colinérgicos/farmacología , Receptores de Canales Iónicos con Asa de Cisteína Activados por Ligando/antagonistas & inhibidores , Antagonistas del GABA/farmacología , Plexo Mientérico/citología , Neuronas/efectos de los fármacos , Antagonistas de la Serotonina/farmacología , Animales , Bicuculina/farmacología , Receptores de Canales Iónicos con Asa de Cisteína Activados por Ligando/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Cobayas , Hexametonio/farmacología , Masculino , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Plexo Mientérico/metabolismo , Neuronas/metabolismo , Ondansetrón/farmacología , Picrotoxina/farmacología , Cultivo Primario de Células , Receptores Colinérgicos/química , Receptores Colinérgicos/metabolismo , Receptores de GABA/metabolismo , Receptores de Serotonina/química , Receptores de Serotonina/metabolismoRESUMEN
Vanadium (V) has a variety of applications that make it suitable for use in ceramic production and decoration, production of pigments for a variety of products, an accelerator for drying paint, production of aniline black dye, and as a mordant in coloring textiles. Taking advantage of its hardness, resilience, ability to form alloys, and its resistance to corrosion, V is also used in the production of tools, steel, machinery, and surgical implants. V is employed in producing photographic developers, batteries, and semi-conductors, and in catalyst-based recycling processes. As technologies have evolved, the use of V has increased in jet aircraft and space technology, as well as in manufacture of ultraviolet filter glass to prevent radiation injury. Due to these myriad uses, the potential for occupational exposure to V is ever-evident. Similarly, there is an increased risk for environmental contamination by V agents themselves or as components of by-products released into the environment. For example, the use of V in sulfuric acid production results in the release of soot and/or fly ash rich in vanadium pentoxide. Petroleum refinery, smelting, welding, and cutting of V-rich steel alloy, the cleaning and repair of oil-fired boilers, and catalysis of chemical productions are other sources of increased airborne V-bearing particles in local/distant environments. Exposure of non-workers to V is an increasing health concern. Studies have demonstrated associations between exposure to airborne V-bearing particles (as part of air pollution) and increased risks of a variety of pathologies like hypertension, dysrhythmia, systemic inflammation, hyper-coagulation, cancers, and bronchial hyper-reactivity. This paper will provide a review of the history of V usage in occupational settings, documented exposure levels, environmental levels of V associated with pollution, epidemiologic data relating V exposure(s) to adverse health outcomes, and governmental responses to protect both workers and non-workers from exposure to this metal.
Asunto(s)
Exposición a Riesgos Ambientales , Exposición Profesional , Vanadio/metabolismo , Animales , Bioquímica , Exposición a Riesgos Ambientales/efectos adversos , Salud , Humanos , Exposición Profesional/efectos adversos , Evaluación de Resultado en la Atención de Salud , Estados Unidos , Vanadio/química , Vanadio/toxicidadRESUMEN
Estimation of joint torques through musculoskeletal models and measurements of muscle activations can be used for real-time control of robotic devices for rehabilitation. Many works developed models for analytic one joint motion, but less are found that develop models for functional multijoint movements. In this work we develop a methodology for tuning and optimizing Hill-based EMG-driven models oriented to the force control of robotic exoskeletons for the upper limb, selecting the more suitable parameters to be optimized. The model is tuned from experimental data obtained from healthy people. The torques estimated by that model will serve as reference for force-based control of an exoskeleton for rehabilitation.
Asunto(s)
Electromiografía/métodos , Articulaciones/fisiología , Movimiento/fisiología , Músculos/fisiología , Torque , Extremidad Superior/fisiología , Adulto , Brazo/fisiología , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Análisis de Regresión , Robótica , Adulto JovenRESUMEN
BACKGROUND: Nucleotides released to the extracellular space stimulate purinergic receptors, and their effects are modulated by ectonucleotidases. The role of ATP in the allergic bronchospasm has been scantly studied. METHODS: We used several techniques (plethysmography, organ baths, confocal microscopy, RT-PCR, ATP measurement) to explore the role of nucleotides and ectonucleotidases in the allergic bronchospasm in guinea pigs. RESULTS: While allergenic challenge with a low-dose ovalbumin (OVA) only produced a small bronchospasm (~2-fold the basal lung resistance), previous inhibition of ectonucleotidases by ARL-67156 greatly intensified this response (~11-fold the basal lung resistance, with 44% mortality). Bronchoalveolar lavage fluid obtained during this bronchospasm contained increased ATP concentration. This potentiation was abolished by antagonism of purinergic receptors (suramin+RB2) or TXA2 receptor (SQ29548), or by intratracheal apyrase. In tracheal rings and lung parenchyma strips, OVA caused a concentration-dependent contraction. Suramin+RB2 or levamisole produced a significant rightward displacement of this response, and ARL-67156 did not modify it. Platelets stimulated with OVA released ATP. Confocal images of nonsensitized tracheas showed slight fluorescence for P2Y6 receptors in epithelium and none for P2Y4 . Sensitized animals showed strong fluorescence to both receptors and to alkaline phosphatase in the airway epithelium. This correlated with a large increment in mRNA for P2Y4 and P2Y6 receptors in sensitized animals. CONCLUSIONS: Nucleotides greatly potentiate the allergic bronchospasm when ectonucleotidases activity is diminished, and this effect is probably favored by the upregulation of P2Y4 and P2Y6 receptors in airway epithelium during sensitization. These results prompt for further research on these mechanisms in human asthma.
Asunto(s)
Espasmo Bronquial/enzimología , Espasmo Bronquial/inmunología , Hipersensibilidad/enzimología , Hipersensibilidad/inmunología , Nucleotidasas/metabolismo , Nucleótidos/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Fosfatasa Alcalina/metabolismo , Animales , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Espasmo Bronquial/inducido químicamente , Espasmo Bronquial/genética , Líquido del Lavado Bronquioalveolar/inmunología , Relación Dosis-Respuesta a Droga , Espacio Extracelular/metabolismo , Cobayas , Hidrólisis/efectos de los fármacos , Hipersensibilidad/genética , Nucleotidasas/antagonistas & inhibidores , Ovalbúmina/efectos adversos , Ovalbúmina/inmunología , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2/metabolismoRESUMEN
Olfactory neuroepithelial cells in culture have been proposed as a model to study the physiopathology of psychiatric disorders and biomarker characterization for diagnosis. In patients with schizophrenia (SZ) and bipolar disorder (BD) diminished microtubule-associated proteins expression occurs, which might lead to aberrant microtubular organization and which in turn may affect Ca(2+) voltage-activated currents. The aim of this work was to characterize of microtubule organization as well as of the L-type Ca(2+) current in neuronal precursors obtained from nasal exfoliates of patients with SZ and BD. Microtubule organization was studied by immunofluorescence with a specific anti-III ß-tubulin antibody and by quantification of globular and assembled tubulin by Western blot. L-type current recording was performed by whole-cell patch-clamp technique and nifedipine superfusion. The results showed differential altered microtubular organization in neuronal precursors of SZ and BD. Short microtubules were observed in BD neurons, while extensive, unstained subcellular areas and disorganized microtubules were evident in SZ neuronal precursors. Patients with BD showed a decrease in amounts of tubulin in total homogenates and 40% decrease in the globular fraction. However, L-type current in BD was similar to that in healthy subjects (HS). In contrast, this current in SZ was 50% lower. These reduction in L-type current in SZ together with differential microtubule alterations are potential biomarkers that may differentiates SZ and BD.
Asunto(s)
Trastorno Bipolar , Canales de Calcio Tipo L , Calcio/metabolismo , Microtúbulos , Neuronas , Esquizofrenia , Biomarcadores/metabolismo , Trastorno Bipolar/metabolismo , Trastorno Bipolar/patología , Canales de Calcio Tipo L/metabolismo , Células Cultivadas , Humanos , Microtúbulos/metabolismo , Microtúbulos/patología , Neuronas/metabolismo , Neuronas/patología , Nifedipino , Técnicas de Placa-Clamp , Esquizofrenia/metabolismo , Esquizofrenia/patologíaRESUMEN
P2X2 plays an important role in ATP signaling in guinea pig myenteric plexus. Here, we cloned and characterized three P2X2 isoforms expressed in myenteric neurons. RT/PCR was used to amplify the cDNA of P2X2 variants. These were expressed in Xenopus oocytes, and nucleotide-induced membrane currents were recorded with the two-electrode voltage clamp technique. Three P2X2 cDNAs were identified in myenteric single neurons, named P2X2-1, P2X2-2 and P2X2-4. Based on the analysis of the structural organization of these variants we predicted that P2X2-2 is the fully processed variant, which lead us to propose a new exon-intron arrangement of P2X2 receptor gene with 12 exons and 11 introns. In agreement with this new model, the intron 11 is retained in P2X2-1 and P2X2-4 variants by alternative splicing. Expression of P2X2-1, P2X2-2 and P2X2-4 were found in 92, 42 and 37%, respectively, out of 40 analyzed single neurons. P2X2-4 does not form functional channels, and homomeric channels formed by P2X2-1 and P2X2-2 have different pharmacological profile. Thus, the former receptor is more sensitive to ATP, BzATP, and PPADS, whereas, suramin inhibited both receptors in a biphasic- and monophasic-manner, respectively. α,ß-meATP has very low efficacy on either channel. Furthermore, ionic currents mediated by P2X2-1 have slower desensitization than P2X2-2. These results indicate that P2X2-1 was the most common P2X2 transcript in myenteric neurons and displays significant phenotypical changes implicating that retention of the intron 11 plays a major role in ATP signaling in the intestinal myenteric plexus.
Asunto(s)
Intrones/efectos de los fármacos , Intrones/genética , Plexo Mientérico/efectos de los fármacos , Neuronas/efectos de los fármacos , Receptores Purinérgicos P2X2/efectos de los fármacos , Receptores Purinérgicos P2X2/genética , Secuencia de Aminoácidos , Animales , Células Cultivadas , Clonación Molecular , ADN Complementario/biosíntesis , ADN Complementario/genética , Fenómenos Electrofisiológicos , Exones/genética , Exones/fisiología , Femenino , Cobayas , Intestino Delgado/efectos de los fármacos , Intestino Delgado/metabolismo , Cinética , Masculino , Potenciales de la Membrana/efectos de los fármacos , Datos de Secuencia Molecular , Plexo Mientérico/citología , Oocitos/metabolismo , Técnicas de Placa-Clamp , Isoformas de Proteínas , Reacción en Cadena en Tiempo Real de la Polimerasa , Xenopus laevisRESUMEN
This paper develops a Hill model based technique to estimate human elbow torque from sEMG measurements. Some new parameters are included in the optimization process in order to improve the resulting estimated torque. These parameters correspond to activation levels of muscles involved in motion generation. They have not previously been used in other works dealing with this kind of model. Results from experiments with several subjects in different movement conditions and using the new optimized parameters lead to some conclusions about the generality of the optimized models and the influence of the new parameters on the improvement of the estimation.
Asunto(s)
Articulación del Codo/fisiología , Electromiografía , Modelos Biológicos , Músculo Esquelético/fisiología , Torque , Adulto , Humanos , MasculinoRESUMEN
There is an increased concern about the health effects that air-suspended particles have on human health which have been dissected in animal models. Using CD-1 mouse, we explore the effects that vanadium inhalation produce in different tissues and organs. Our findings support the systemic effects of air pollution. In this paper, we describe our findings in different organs in our conditions and contrast our results with the literature.
Asunto(s)
Contaminación del Aire/efectos adversos , Material Particulado/toxicidad , Vanadio/toxicidad , Animales , Huesos/efectos de los fármacos , Huesos/patología , Sistema Nervioso Central/efectos de los fármacos , Sistema Nervioso Central/patología , Roturas del ADN de Cadena Simple , Humanos , Sistema Inmunológico/patología , Inhalación , Hígado/efectos de los fármacos , Hígado/patología , Pulmón/efectos de los fármacos , Pulmón/patología , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/patología , Ratones , Modelos Animales , Especies Reactivas de Oxígeno/metabolismo , Reproducción/efectos de los fármacos , Bazo/efectos de los fármacos , Bazo/patologíaRESUMEN
Brain imaging and histopathological studies suggest that neurodevelopmental anomalies play a key role in the etiology of schizophrenia (SZ) and bipolar disorder (BD). New neuron formation and maturation occur in human olfactory epithelium throughout life. Therefore, the olfactory epithelium has been proposed as a model to study alterations in neurodevelopment, particularly in some psychiatric diseases. However, former studies were done with olfactory epithelium biopsies taken post mortem or under anesthesia from patients with SZ and BD. In this work we have developed a new method to obtain viable neural precursors by exfoliation of the anterior region of the medial lateral turbinate of the nasal cavity from healthy controls, and ambulatory patients. Cells were propagated to establish neural precursor banks. Thawed cells showed cytoskeletal phenotypes typical of developing neurons. They also conserved the ability to differentiate in presence of 2mM dibutyril-cyclic adenosine monophosphate, and maintained voltage-operated Ca(2+) currents in culture. Moreover, proportions of neuronal maturation stages were maintained in cultured exfoliates obtained from SZ and BD patients. Data support that neural precursors obtained from a nasal exfoliate are an excellent experimental model to later approach studies on biomarkers, neural development and cellular alterations in the pathophysiology of SZ and BD.
Asunto(s)
Trastorno Bipolar/patología , Linaje de la Célula , Mucosa Nasal/citología , Neuronas , Esquizofrenia/patología , Células Madre , Adulto , Trastorno Bipolar/etiología , Linaje de la Célula/fisiología , Células Cultivadas , Femenino , Humanos , Masculino , Mucosa Nasal/patología , Neuronas/patología , Neuronas/fisiología , Esquizofrenia/etiología , Células Madre/patología , Células Madre/fisiología , Adulto JovenRESUMEN
Nasal epithelium is a source for identifying atmospheric pollution impact. Antioxidants play a relevant role in the protection of the cells from environmental injury, but scarce information is available about the interaction of endogenous antioxidants and genotoxic damage in nasal epithelium from urban populations highly exposed to traffic-generated air pollutants. An immunocytochemical and genotoxic evaluation was implemented in nasal cell epithelium in a population chronically exposed to atmospheric pollution from autumn 2004 to autumn 2005. Superoxide dismutase (SOD) and Catalase (CAT) were evaluated in nasal scrapings by morphometry and genotoxicity by comet assay. An increase in DNA damage correlates with a decrease in SOD and CAT in nasal cells during autumn and the inverse result was observed during summer (R = 0.88). Not only should exogenous antioxidant supplements be encouraged, but also a healthy diet to strengthen intracellular defenses against oxidative stress induced by exposure to air pollutants.