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1.
Vet J ; 254: 105395, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31836169

RESUMEN

Meningoencephalitis of unknown origin (MUO) is a common inflammatory disease of the central nervous system. Several studies investigated finding prognostic factors, but results are contradictory. The aim of this study was to determine the concentrations of blood lactate (Blood-L) and cerebrospinal fluid lactate (CSF-L) in dogs with MUO for prognostic purposes. A total of 45 dogs with MUO (MUO group) and 11 with idiopathic epilepsy (IE group) were included. In the MUO group, 22 dogs were treated with prednisolone + cytosine arabinoside, 17 with prednisolone ± cyclosporine, and six received no treatment. In the MUO group, there was a strong-moderate positive correlation between Blood-L and CSF-L (ρ = 0.63557; P < 0.0001), a strong-moderate negative correlation between survival and CSF-L (ρ= -0.50210; P < 0.0004), and a weak negative correlation between survival and Blood-L (ρ= -0.35685; P < 0.0220). Dogs with a favourable response to treatment at 1 month had lower initial concentrations of Blood-L and CSF-L (P < 0.0010; P < 0.0037), and those with a worse response had higher values (P < 0.0497; P < 0.0004). Dogs that remained stable with treatment showed lower CSF-L concentrations (P < 0.0013). Dogs with Blood-L>4 mmol/L (P < 0.03) and/or CSF-L> 4 mmol/L (P < 0.009) had lower survival rates with the latter also showing more severe signs, probably indicating severe neuronal damage. These findings suggest that concentrations of CSF-L and Blood-L in dogs with MUO could be used as prognostic indicators.


Asunto(s)
Enfermedades de los Perros/sangre , Enfermedades de los Perros/líquido cefalorraquídeo , Ácido Láctico/sangre , Ácido Láctico/líquido cefalorraquídeo , Meningoencefalitis/veterinaria , Animales , Antiinflamatorios/uso terapéutico , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Citarabina/uso terapéutico , Perros , Femenino , Masculino , Meningoencefalitis/sangre , Meningoencefalitis/líquido cefalorraquídeo , Meningoencefalitis/tratamiento farmacológico , Prednisolona/uso terapéutico , Pronóstico , Estudios Prospectivos
2.
Environ Pollut ; 247: 371-382, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30690233

RESUMEN

Tributyltin (TBT) is an organotin environmental pollutant widely used as an agricultural and wood biocide and in antifouling paints. Countries began restricting TBT use in the 2000s, but their use continues in some agroindustrial processes. We studied the acute effect of TBT on cardiac function by analyzing myocardial contractility and Ca2+ handling. Cardiac contractility was evaluated in isolated papillary muscle and whole heart upon TBT exposure. Isolated ventricular myocytes were used to measure calcium (Ca2+) transients, sarcoplasmic reticulum (SR) Ca2+ content and SR Ca2+ leak (as Ca2+ sparks). Reactive oxygen species (ROS), as superoxide anion (O2•-) was detected at intracellular and mitochondrial myocardium. TBT depressed cardiac contractility and relaxation in papillary muscle and intact whole heart. TBT increased cytosolic, mitochondrial ROS production and decreased mitochondrial membrane potential. In isolated cardiomyocytes TBT decreased both Ca2+ transients and SR Ca2+ content and increased diastolic SR Ca2+ leak. Decay of twitch and caffeine-induced Ca2+ transients were slowed by the presence of TBT. Dantrolene prevented and Tiron limited the reduction in SR Ca2+ content and transients. The environmental contaminant TBT causes cardiotoxicity within minutes, and may be considered hazardous to the mammalian heart. TBT acutely induced a negative inotropic effect in isolated papillary muscle and whole heart, increased arrhythmogenic SR Ca2+ leak leading to reduced SR Ca2+ content and reduced Ca2+ transients. TBT-induced myocardial ROS production, may destabilize the SR Ca2+ release channel RyR2 and reduce SR Ca2+ pump activity as key factors in the TBT-induced negative inotropic and lusitropic effects.


Asunto(s)
Cardiotoxicidad/metabolismo , Compuestos de Trialquiltina/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Calcio/metabolismo , Mitocondrias/metabolismo , Contracción Miocárdica , Miocardio/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismo , Canal Liberador de Calcio Receptor de Rianodina , Retículo Sarcoplasmático/metabolismo
3.
Vet Comp Oncol ; 15(4): 1280-1294, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27578604

RESUMEN

Limited veterinary literature is available regarding prognostic markers for canine renal cell carcinoma (CRCC). We retrospectively evaluated COX-2 expression, histological and clinical features associated with prognosis of CRCC. Sixty-four cases post-nephrectomy were included, 54 had histopathological assessment and 30 had COX-2 immunostaining performed. Eight dogs (13%) had metastatic disease at initial diagnosis. Twenty-seven dogs (42%) received adjuvant therapy after nephrectomy. On univariate analysis, COX-2 expression, mitotic index (MI), histologic type, vascular invasion, neoplastic invasiveness and metastasis at diagnosis were significantly associated with overall median survival time (MST). COX-2 score (COX-2 score > 3 MST 420 days versus 1176 days if COX-2 score <3; P = 0.011) and MI (MI > 30 MST 120 days versus 540 days for MI < 30; P = 0.003) were the only variables associated with CRCC outcome on multivariate analysis. The addition of MI and COX-2 immunostaining to standard histopathological evaluation would help predicting outcome in CRCC patients.


Asunto(s)
Carcinoma de Células Renales/veterinaria , Ciclooxigenasa 2/metabolismo , Enfermedades de los Perros/diagnóstico , Neoplasias Renales/veterinaria , Nefrectomía/veterinaria , Animales , Carcinoma de Células Renales/diagnóstico , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/cirugía , Enfermedades de los Perros/mortalidad , Enfermedades de los Perros/patología , Enfermedades de los Perros/cirugía , Perros , Femenino , Neoplasias Renales/diagnóstico , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Masculino , Índice Mitótico/veterinaria , Invasividad Neoplásica/patología , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento
4.
Plant Biol (Stuttg) ; 18(6): 973-980, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27500664

RESUMEN

Context-dependency in species interactions is widespread and can produce concomitant patterns of context-dependent selection. Masting (synchronous production of large seed crops at irregular intervals by a plant population) has been shown to reduce seed predation through satiation (reduction in rates of seed predation with increasing seed cone output) and thus represents an important source of context-dependency in plant-animal interactions. However, the evolutionary consequences of such dynamics are not well understood. Here we describe masting behaviour in a Mediterranean model pine species (Pinus pinaster) and present a test of the effects of masting on selection by seed predators on reproductive output. We predicted that masting, by enhancing seed predator satiation, could in turn strengthen positive selection by seed predators for larger cone output. For this we collected six-year data (spanning one mast year and five non-mast years) on seed cone production and seed cone predation rates in a forest genetic trial composed by 116 P. pinaster genotypes. Following our prediction, we found stronger seed predator satiation during the masting year, which in turn led to stronger seed predator selection for increased cone production relative to non-masting years. These findings provide evidence that masting can alter the evolutionary outcome of plant-seed predator interactions. More broadly, our findings highlight that changes in consumer responses to resource abundance represent a widespread mechanism for predicting and understanding context dependency in plant-consumer evolutionary dynamics.


Asunto(s)
Pinus/fisiología , Semillas/fisiología , Animales , Evolución Biológica , Biomasa , Conducta Alimentaria , Bosques , Genotipo , Pinus/crecimiento & desarrollo , Conducta Predatoria , Reproducción , Saciedad , Semillas/crecimiento & desarrollo
5.
Rev. Fac. Odontol. (B.Aires) ; 31(70): 24-30, ene.-jun. 2016. ilus
Artículo en Español | LILACS | ID: biblio-835574

RESUMEN

La ciencia odontológica cuenta con diversas metodologías a la hora de brindar auxilio a la Justicia, tanto en la resolución de casos criminales como en procedimientos de índole civil y laboral. La odontología legal requiere de un trabajo interdisciplinario con las otrasespecialidades odontológicas. En ese contexto, el rol capital del perito odontólogo es contribuir al esclarecimiento de la identidad de unapersona. El diente es susceptible de variantes fisiológicas y patológicas en sus estructuras, como así también estigmas inherentes a los tratamientos restauradores, hechos que confiere información dental que individualiza a una persona. Las piezas dentarias pueden ser utilizadas como un arma en determinadas circunstancias, brindando información relevante sobre los caracteres odontológicos de la víctimay/o del agresor, pudiendo entonces desempeñar la odontología legal un importante rol en la investigación de situaciones de agresión sexual yabuso en todas las edades. El odontólogo en su tarea asistencial tiene la responsabilidad de labrar y documentar de manera fiel y completasu devenir profesional, pudiendo ser requerido por las autoridades encargadas de administrar Justicia en casos de responsabilidad profesional, negligencia, fraude, abuso, e identificación de restos humanos.


Dental science has various methodologies when providing aid to justice, both in solving criminal cases and civil procedures and labor issues.Legal Dentistry requires interdisciplinary work with other dental specialties. In this context, the principal role of the dentist expert is helpclarify the identity of a person. The tooth is subject to physiological and pathological variations in their structures, as well as inherentstigmas restorative treatments, facts which confers dental individualized information to a person. The teeth can be used as a weapon incertain circumstances, providing relevant information about dental characteristics of the victim and/or perpetrator can then LegalDentistry play an important role in investigating cases of sexual assault and abuse in all the ages. The dentist in their care task isresponsible for faithfully document and complete their professional procedure that may be required by the authorities responsible foradministering justice in cases of professional liability, negligence, fraud, abuse, and identification of human remains.


Asunto(s)
Humanos , Masculino , Femenino , Odontología Forense/legislación & jurisprudencia , Odontología Forense/normas , Identificación de Víctimas , Mordeduras y Picaduras , Determinación de la Edad por los Dientes/métodos , Identificación de la Prótesis Dental/métodos , Legislación en Odontología/normas , Radiografía Dental/normas , Registros Odontológicos/normas , Víctimas de Desastres/legislación & jurisprudencia , Violencia Doméstica/legislación & jurisprudencia
7.
Cytopathology ; 26(5): 288-96, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25487739

RESUMEN

OBJECTIVES: The application of molecular tests to thyroid fine needle aspiration (FNA) has been shown to be a valuable tool to better refine the pre-operative malignant risk of patients with indeterminate cytology results. In this study, we investigated the feasibility of using the laser capture microdissection (LCM) technique to obtain DNA and RNA for molecular tests in routine thyroid FNA smears. METHODS: Nine coupled FNA and histological retrospective cases and 31 prospective FNA cases with a follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN) diagnosis were included in this study. Both cytological and histological specimens were investigated by direct sequencing and reverse transcription-polymerase chain reaction (RT-PCR) for BRAF and RAS mutations and for PAX8/PPARG and RET/PTC rearrangements, respectively. RESULTS: LCM yielded good DNA and RNA quality in all cases (100%) in both series, irrespective of the staining used (Giemsa, Papanicolaou, immunostain for thyroglobulin) and the cytology technique (conventional or liquid-based preparations). Total mutations found in the FNA and in the corresponding histological specimen in both series were: one PAX8/PPARG rearrangement in a follicular carcinoma (FC), four NRAS mutations [in two FCs, one papillary carcinoma and one follicular adenoma (FA)] and one HRAS mutation in one FA. The sensitivity was 67% and the specificity was 91%. CONCLUSIONS: LCM is a valuable tool to obtain good quality DNA and RNA for molecular tests in cytological material from thyroid FNA, and can be a useful option in the management of patients with an FN/SFN FNA diagnosis.


Asunto(s)
Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/patología , Adenoma/diagnóstico , Adenoma/patología , Glándula Tiroides/patología , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/patología , Adenocarcinoma Folicular/genética , Adenoma/genética , Biopsia con Aguja Fina/métodos , Citodiagnóstico/métodos , ADN/genética , Femenino , Humanos , Captura por Microdisección con Láser/métodos , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular/métodos , Mutación/genética , Factor de Transcripción PAX8 , PPAR gamma/genética , Factores de Transcripción Paired Box/genética , Estudios Prospectivos , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-ret/genética , ARN/genética , Estudios Retrospectivos , Neoplasias de la Tiroides/genética , Proteínas ras/genética
10.
Physiol Genomics ; 45(4): 138-50, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23269701

RESUMEN

Blood pressure (BP) is a dynamic phenotype that varies rapidly to adjust to changing environmental conditions. Standing upright is a recent evolutionary trait, and genetic factors that influence postural adaptations may contribute to BP variability. We studied the effect of posture on the genetics of BP and intermediate BP phenotypes. We included 384 sib-pairs in 64 sib-ships from families ascertained by early-onset hypertension and dyslipidemia. Blood pressure, three hemodynamic and seven neuroendocrine intermediate BP phenotypes were measured with subjects lying supine and standing upright. The effect of posture on estimates of heritability and genetic covariance was investigated in full pedigrees. Linkage was conducted on 196 candidate genes by sib-pair analyses, and empirical estimates of significance were obtained. A permutation algorithm was implemented to study the postural effect on linkage. ADRA1A, APO, CAST, CORIN, CRHR1, EDNRB, FGF2, GC, GJA1, KCNB2, MMP3, NPY, NR3C2, PLN, TGFBR2, TNFRSF6, and TRHR showed evidence of linkage with any phenotype in the supine position and not upon standing, whereas AKR1B1, CD36, EDNRA, F5, MMP9, PKD2, PON1, PPARG, PPARGC1A, PRKCA, and RET were specifically linked to standing phenotypes. Genetic profiling was undertaken to show genetic interactions among intermediate BP phenotypes and genes specific to each posture. When investigators perform genetic studies exclusively on a single posture, important genetic components of BP are missed. Supine and standing BPs have distinct genetic signatures. Standardized maneuvers influence the results of genetic investigations into BP, thus reflecting its dynamic regulation.


Asunto(s)
Adaptación Fisiológica/genética , Presión Sanguínea/genética , Ligamiento Genético , Postura , Adulto , Algoritmos , Salud de la Familia , Femenino , Efecto Fundador , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo/métodos , Humanos , Hipertensión/genética , Masculino , Modelos Genéticos , Fenotipo , Polimorfismo de Nucleótido Simple , Hermanos , Posición Supina
11.
Pathologica ; 103(5): 307-10, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22393688

RESUMEN

Although lymphoma involvement of the gallbladder, especially by MALT and large-cell types, is rare, this possibility should be considered in patients with symptoms of acute cholecystitis. A cholecystectomy was performed in a 79-year-old male patient with a clinical diagnosis of chronic cholecystitis. Histologically, the specimen showed an incidental finding of a small lymphocytic lymphoma (CLL) by morphologic and immunophenotyping studies, subsequently confirmed with flow cytometric analysis of blood. During follow-up, multiple lymph node enlargement was detected. An axillary node, excised and submitted to our department, was positive for lymphoma involvement. The bone marrow was negative.


Asunto(s)
Colecistitis/patología , Neoplasias de la Vesícula Biliar/patología , Hallazgos Incidentales , Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células B/patología , Anciano , Antígenos CD/metabolismo , Biomarcadores de Tumor/metabolismo , Colecistitis/complicaciones , Colecistitis/cirugía , Enfermedad Crónica , Neoplasias de la Vesícula Biliar/metabolismo , Neoplasias de la Vesícula Biliar/cirugía , Humanos , Inmunofenotipificación , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/cirugía , Ganglios Linfáticos/patología , Linfoma de Células B/metabolismo , Linfoma de Células B/cirugía , Masculino , Neoplasias Primarias Múltiples
12.
J Electromyogr Kinesiol ; 20(4): 580-9, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20044273

RESUMEN

This work investigated motor unit (MU) recruitment during transcutaneous electrical stimulation (TES) of the tibialis anterior (TA) muscle, using experimental and simulated data. Surface electromyogram (EMG) and torque were measured during electrically-elicited contractions at different current intensities, on eight healthy subjects. EMG detected during stimulation (M-wave) was simulated selecting the elicited MUs on the basis of: (a) the simulated current density distribution in the territory of each MU and (b) the excitation threshold characteristic of the MU. Exerted force was simulated by adding the contribution of each of the elicited MUs. The effects of different fat layer thickness (between 2 and 8mm), different distributions of excitation thresholds (random excitation threshold, higher threshold for larger MUs or smaller MUs), and different MU distributions within the muscle (random distribution, larger MU deeper in the muscle, smaller MU deeper) on EMG variables and torque were tested. Increase of the current intensity led to a first rapid increase of experimental M-wave amplitude, followed by a plateau. Further increases of the stimulation current determined an increase of the exerted force, without relevant changes of the M-wave. Similar results were obtained in simulations. Rate of change of conduction velocity (CV) and leading coefficient of the second order polynomial interpolating the force vs. stimulation level curve were estimated as a function of increasing current amplitudes. Experimental data showed an increase of estimated CV with increasing levels of the stimulation current (for all subjects) and a positive leading coefficient of force vs. stimulation current curve (for five of eight subjects). Simulations matched the experimental results only when larger MUs were preferably located deeper in the TA muscle (in line with a histochemical study). Marginal effect of MU excitation thresholds was observed, suggesting that MUs closer to the stimulation electrode are recruited first during TES regardless of their excitability.


Asunto(s)
Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Reclutamiento Neurofisiológico/fisiología , Estimulación Eléctrica Transcutánea del Nervio , Adulto , Electromiografía , Humanos , Masculino , Músculo Esquelético/inervación , Conducción Nerviosa
14.
Neuroscience ; 147(1): 46-52, 2007 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-17521826

RESUMEN

Long-term memory formation depends on protein and mRNA synthesis that subserves synaptic reorganization. The removal of pre-existing inhibitory proteins by the ubiquitin-proteasome system (UPS) is proposed as a crucial step to support these modifications. The activation of the constitutive transcription factor nuclear factor kappaB (NF-kappaB) depends on the degradation of the inhibitor of NF-kappaB (IkappaB) by the UPS. Here we study the effect of a UPS inhibitor, MG132, on long-term memory consolidation and NF-kappaB activation in the learning paradigm of the crab Chasmagnathus, a model in which this transcription factor plays a key role. Here we found that administration of MG132 interferes with long-term memory but not with short-term memory, and no facilitatory effects were found. Then we studied the effect of the UPS inhibitor on NF-kappaB pathway, finding that MG132 blocks the activation of NF-kappaB induced by training. These results suggest that the UPS is necessary for long-term memory consolidation, allowing for the activation of NF-kappaB as one of the target molecular pathways.


Asunto(s)
Braquiuros/enzimología , Condicionamiento Clásico/fisiología , Memoria/fisiología , FN-kappa B/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Animales , Condicionamiento Clásico/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/farmacología , Relación Dosis-Respuesta a Droga , Leupeptinas/farmacología , Masculino , Memoria/efectos de los fármacos , Actividad Motora , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/fisiología , Inhibidores de Proteasoma , Factores de Tiempo , Ubiquitina/efectos de los fármacos , Ubiquitina/metabolismo
16.
J Electromyogr Kinesiol ; 16(5): 498-505, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16291500

RESUMEN

The aims of this study were: (1) to develop and assess reproducibility of a new method for measuring masticatory force in the intercuspal position; (2) to test the reproducibility of surface EMG signal amplitude and spectral variables in constant force contractions of jaw elevator muscles and its dependency on inter-electrode distance. The study was performed on the masseter and temporalis anterior muscles of both sides of nine healthy volunteers. An intraoral compressive-force sensor was used to measure maximal voluntary contraction forces in the intercuspal position and to provide a visual feedback on sub-maximal forces to the subject. Three experimental sessions were performed in three days. In each session, three isometric contractions at 80% of the maximal force were sustained by the subjects for 30s. The intra-class correlation coefficient (ICC) of the maximal force measure was 71.9%. ICC of average rectified value and mean power spectral frequency of the EMG signal increased with inter-electrode distance, with values larger than 70% with 30 mm inter-electrode distance. It was concluded that surface EMG variables measured in isometric contractions of the jaw elevator muscles with the proposed force recording system show good reproducibility for clinical applications when a 30 mm inter-electrode distance is considered.


Asunto(s)
Fuerza de la Mordida , Análisis del Estrés Dental/métodos , Electromiografía/métodos , Contracción Isométrica/fisiología , Músculo Masetero/fisiología , Esfuerzo Físico/fisiología , Músculo Temporal/fisiología , Adulto , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Vet Rec ; 157(19): 586-9, 2005 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-16272546

RESUMEN

A previously healthy Scottish terrier developed verminous pneumonia due to Filaroides hirthi. The disease was diagnosed on the basis of cytology of a transtracheal wash, which contained 17 per cent eosinophils and a large number of parasite larvae. Treatment with 50 mg/kg bodyweight fenbendazole daily for three weeks eliminated the parasites and improved the clinical condition of the dog.


Asunto(s)
Enfermedades de los Perros/tratamiento farmacológico , Filariasis/veterinaria , Neumonía/veterinaria , Animales , Antinematodos/uso terapéutico , Enfermedades de los Perros/parasitología , Perros , Femenino , Fenbendazol/uso terapéutico , Filariasis/complicaciones , Filariasis/tratamiento farmacológico , Filarioidea/aislamiento & purificación , Neumonía/tratamiento farmacológico , Neumonía/etiología , España
18.
Am J Hum Genet ; 76(5): 815-32, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15800845

RESUMEN

The Saguenay-Lac St-Jean population of Quebec is relatively isolated and has genealogical records dating to the 17th-century French founders. In 120 extended families with at least one sib pair affected with early-onset hypertension and/or dyslipidemia, we analyzed the genetic determinants of hypertension and related cardiovascular and metabolic conditions. Variance-components linkage analysis revealed 46 loci after 100,000 permutations. The most prominent clusters of overlapping quantitative-trait loci were on chromosomes 1 and 3, a finding supported by principal-components and bivariate analyses. These genetic determinants were further tested by classifying families by use of LOD score density analysis for each measured phenotype at every 5 cM. Our study showed the founder effect over several generations and classes of living individuals. This quantitative genealogical approach supports the notion of the ancestral causality of traits uniquely present and inherited in distinct family classes. With the founder effect, traits determined within population subsets are measurably and quantitatively transmitted through generational lineage, with a precise component contributing to phenotypic variance. These methods should accelerate the uncovering of causal haplotypes in complex diseases such as hypertension and metabolic syndrome.


Asunto(s)
Efecto Fundador , Predisposición Genética a la Enfermedad , Hipertensión/genética , Adolescente , Adulto , Canadá , Femenino , Francia/etnología , Ligamiento Genético , Variación Genética , Humanos , Escala de Lod , Masculino , Persona de Mediana Edad , Fenotipo , Carácter Cuantitativo Heredable , Población Blanca/genética
20.
Muscle Nerve ; 29(6): 823-33, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15170615

RESUMEN

Muscle-fiber conduction velocity (CV) was estimated from surface electromyographic (EMG) signals during isometric contractions and during short (150-200 ms), explosive, dynamic exercises. Surface EMG signals were recorded with four linear adhesive arrays from the vastus lateralis and medialis muscles of 12 healthy subjects. Isometric contractions were at linearly increasing force from 0% to 100% of the maximum. The dynamic contractions consisted of explosive efforts of the lower limb on a sledge ergometer. For the explosive contractions, muscle-fiber CV was estimated in seven time-windows located along the ascending time interval of the force. There was a significant correlation between CV values during the isometric ramp and explosive contractions (R = 0.75). Moreover, CV estimates increased significantly from (mean +/- SD) 4.32 +/- 0.46 m/s to 4.97 +/- 0.45 m/s during the increasing-force explosive task. It was concluded that CV can be estimated reliably during dynamic tasks involving fast limb movements and that, in these contractions, it may provide important information on motor-unit control properties.


Asunto(s)
Electromiografía/métodos , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas/fisiología , Adulto , Electromiografía/instrumentación , Humanos , Pierna , Masculino , Modelos Biológicos , Neuronas Motoras/fisiología , Músculo Esquelético/citología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología
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