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1.
J Insect Sci ; 19(2)2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30851035

RESUMEN

Certain color patterns in insects show convergent evolution reflecting potentially important biological functions, for example, aposematism and mimicry. This phenomenon has been most frequently documented in Lepidoptera and Coleoptera, but has been less well investigated in Hymenoptera. It has long been recognized that many hymenopterans, especially scelionids (Platygastridae), show a recurring pattern of black head, orange/red mesosoma, and black metasoma (BOB coloration). However, the taxonomic distribution of this striking color pattern has never been documented across the entire order. The main objective of our research was to provide a preliminary tabulation of this color pattern in Hymenoptera, through examination of museum specimens and relevant literature. We included 11 variations of the typical BOB color pattern but did not include all possible variations. These color patterns were found in species belonging to 23 families of Hymenoptera, and was most frequently observed in scelionids, evaniids, and mutillids, but was relatively infrequent in Cynipoids, Diaprioids, Chalcidoids, and Apoids. The widespread occurrence of this color pattern in Hymenoptera strongly suggests convergent evolution and a potentially important function. The BOB color pattern was found in species from all biogeographic regions and within a species it was usually present in both sexes (with a few notable exceptions). In better studied tropical regions, such as Costa Rica, this color pattern was more common in species occurring at lower elevations (below 2,000 m). The biology of the tabulated taxa encompasses both ecto- and endoparasitoids, idiobionts and koinobionts, from a diversity of hosts, as well as phytophagous sawflies.


Asunto(s)
Himenópteros , Pigmentación , Animales , Color , Femenino , Masculino
2.
Arch Toxicol ; 89(10): 1811-25, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25693864

RESUMEN

Evidence indicates that Parkinson's disease (PD), in addition to having a genetic aetiology, has an environmental component that contributes to disease onset and progression. The exact nature of any environmental agent contributing to PD is unknown in most cases. Given its similarity to paraquat, an agrochemical removed from registration in the EU for its suspected potential to cause PD, we have investigated the in vitro capacity of the related herbicide Diquat to cause PD-like cell death. Diquat showed greater toxicity towards SH-SY5Y neuroblastoma cells and human midbrain neural cells than paraquat and also MPTP, which was independent of dopamine transporter-mediated uptake. Diquat caused cell death independently of caspase activation, potentially via RIP1 kinase, with only a minor contribution from apoptosis, which was accompanied by enhanced reactive oxygen species production in the absence of major inhibition of complex I of the mitochondrial respiratory chain. No changes in α-synuclein expression were observed following 24-h or 4-week exposure. Diquat may, therefore, kill neural tissue by programmed necrosis rather than apoptosis, reflecting the pathological changes seen following high-level exposure, although its ability to promote PD is unclear.


Asunto(s)
Apoptosis/efectos de los fármacos , Diquat/toxicidad , Herbicidas/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Humanos , Intoxicación por MPTP/patología , Mitocondrias/metabolismo , Necrosis/inducido químicamente , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/patología , Neuroblastoma/patología , Paraquat/toxicidad , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Factores de Tiempo
3.
Complement Ther Med ; 83: 103059, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38821377

RESUMEN

OBJECTIVE: The study aimed to investigate the feasibility of a remote mindfulness based self-management intervention for individuals with type 2 diabetes. It is important to further our understanding of how to improve self-management to improve health outcomes and low levels of uptake to self-management courses. METHOD: 29 participants with type 2 diabetes were recruited from the University Hospital Coventry and Warwickshire NHS trust. Three groups of participants engaged with a remote mindfulness based self-management intervention, which were delivered sequentially. After each intervention was complete, patient feedback was retrieved and implemented into the following intervention. The quantitative analysis comprised of descriptive statistics, independent sample t-test, paired sample t-test and multiple regression analysis. A qualitative analysis was also conducted through reflexive thematic analysis (RTA) to understand participant's perspective on the intervention. RESULTS: There was a total of 17 who attended the course (59 %) and a total drop out of 12 participants over the three courses (41 %). The qualitative findings reported three main themes: (1) Eating to manage my emotions rather than my diabetes (2) Implementing mindfulness has helped me manage my emotions (3) Medication rather than self-management behaviours control my diabetes. The focus group feedback included participants' appreciation of the community aspect of the intervention and their perception that the current course was more interactive compared to previous interventions. In addition, participants highlighted the importance of offering the course at an earlier stage of diagnosis to provide further support at the beginning of their diabetes journey. No significant findings were reported for the independent sample t-test, paired sample t-test and multiple regression analysis. CONCLUSION: The qualitative findings suggested that the course was beneficial, especially in demonstrating how mindfulness could aid self-management for individuals living with type 2 diabetes. Further funding and trials are warranted to improve the quality of technology used and to assess impact on diabetes control and mental health.


Asunto(s)
Diabetes Mellitus Tipo 2 , Estudios de Factibilidad , Atención Plena , Automanejo , Humanos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/psicología , Atención Plena/métodos , Proyectos Piloto , Masculino , Persona de Mediana Edad , Femenino , Anciano , Adulto
4.
Acta Neurol Belg ; 121(1): 181-189, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32740873

RESUMEN

Post-stroke fatigue (PSF) is a common symptom associated with disability and decreased quality of life. Distinction can be made between perceived fatigue and fatigability. The first aim of this study was to evaluate the prevalence of perceived fatigue and fatigability amongst patients with chronic stroke and to explore how these two parameters relate. The second aim was to study the relationship between modifiable factors (sleep disorders, anxiety, depression and activities of daily living) and fatigue in this population. Sixty-two patients with chronic stroke (> 6 months) were included. Perceived fatigue was evaluated using the Fatigue Severity Scale (FSS). Motor fatigability was assessed with the percent change in meters walked from first to last minute of the 6-min Walk Test and an isometric muscular fatigability test. Subjects also completed self-report questionnaires assessing anxiety and depression (Hospital Anxiety and Depression Scale-HADS), sleep quality (Pittsburgh Sleep Quality Index-PSQI) and activity limitations (ACTIVLIM-stroke). Seventy-one percent of participants presented PSF. There was no correlation between the FSS and motor fatigability. FSS significantly correlated with HADS-Anxiety (ρ = 0.53, P < 0.001), HADS-depression (ρ = 0.63, P < 0.001), PSQI (ρ = 0.51, P < 0.001) and ACTIVLIM (ρ = - 0.30, P < 0.05). A linear regression model showed that the HADS-Depression, the PSQI and the ACTIVLIM explained 46% of the variance of the FSS. A high proportion of chronic stroke patients presents PSF, with no relation between their fatigue and fatigability. Perceived fatigue is associated with potentially modifiable factors: anxious and depressive symptoms, poor sleep quality and activity limitations. Registered at ClinicalTrials.gov (NCT04277234) (21/02/2019).


Asunto(s)
Fatiga/diagnóstico , Fatiga/psicología , Percepción/fisiología , Desempeño Psicomotor/fisiología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/psicología , Anciano , Enfermedad Crónica , Estudios Transversales , Fatiga/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Autoinforme , Accidente Cerebrovascular/complicaciones , Prueba de Paso/psicología , Prueba de Paso/tendencias
6.
J AOAC Int ; 93(2): 576-86, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20480906

RESUMEN

The automated method for enumeration of Escherichia coli, TEMPO EC, in foods uses a dehydrated culture medium and enumeration card containing 48 wells across three different dilutions for the automatic determination of the most probable number (MPN). The alternative method was compared in a multilaboratory collaborative study to AOAC Official Method 966.24. Six food types were artificially contaminated with E. coli: raw ground beef, bagged lettuce, cooked chicken, pasteurized crabmeat, frozen green beans, and pasteurized whole milk. All foods were analyzed for E. coli counts by 11 collaborating laboratories throughout the United States. Test portions from the six food types each contaminated at four different contamination levels were evaluated. The study demonstrated that the TEMPO EC method is a reliable, automated assay for the enumeration of E. coli in foods.


Asunto(s)
Recuento de Colonia Microbiana/métodos , Escherichia coli/metabolismo , Contaminación de Alimentos , Microbiología de Alimentos , Animales , Automatización , Bovinos , Pollos/microbiología , Análisis de los Alimentos , Laboratorios/normas , Carne/microbiología , Reproducibilidad de los Resultados , Proyectos de Investigación , Alimentos Marinos/microbiología , Verduras/microbiología
7.
Nat Commun ; 11(1): 2373, 2020 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-32398638

RESUMEN

Peatlands contain one-third of the world's soil carbon (C). If destabilized, decomposition of this vast C bank could accelerate climate warming; however, the likelihood of this outcome remains unknown. Here, we examine peatland C stability through five years of whole-ecosystem warming and two years of elevated atmospheric carbon dioxide concentrations (eCO2). Warming exponentially increased methane (CH4) emissions and enhanced CH4 production rates throughout the entire soil profile; although surface CH4 production rates remain much greater than those at depth. Additionally, older deeper C sources played a larger role in decomposition following prolonged warming. Most troubling, decreases in CO2:CH4 ratios in gas production, porewater concentrations, and emissions, indicate that the peatland is becoming more methanogenic with warming. We observed limited evidence of eCO2 effects. Our results suggest that ecosystem responses are largely driven by surface peat, but that the vast C bank at depth in peatlands is responsive to prolonged warming.

8.
New Phytol ; 184(2): 387-398, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19694965

RESUMEN

* We used an inadvertent whole-ecosystem 14C label at a temperate forest in Oak Ridge, Tennessee, USA to develop a model (Radix1.0) of fine-root dynamics. Radix simulates two live-root pools, two dead-root pools, non-normally distributed root mortality turnover times, a stored carbon (C) pool, and seasonal growth and respiration patterns. * We applied Radix to analyze measurements from two root size classes (< 0.5 and 0.5-2.0 mm diameter) and three soil-depth increments (O horizon, 0-15 cm and 30-60 cm). * Predicted live-root turnover times were < 1 yr and approximately 10 yr for short- and long-lived pools, respectively. Dead-root pools had decomposition turnover times of approximately 2 yr and approximately 10 yr. Realistic characterization of C flows through fine roots requires a model with two live fine-root populations, two dead fine-root pools, and root respiration. These are the first fine-root turnover time estimates that take into account respiration, storage, seasonal growth patterns, and non-normal turnover time distributions. * The presence of a root population with decadal turnover times implies a lower amount of belowground net primary production used to grow fine-root tissue than is currently predicted by models with a single annual turnover pool.


Asunto(s)
Carbono/metabolismo , Respiración de la Célula , Raíces de Plantas/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Isótopos de Carbono , Ecosistema , Marcaje Isotópico/métodos , Modelos Biológicos , Raíces de Plantas/metabolismo , Estaciones del Año , Tennessee , Factores de Tiempo , Árboles/metabolismo
9.
J Cell Biol ; 138(4): 759-69, 1997 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-9265644

RESUMEN

In this study, we describe the ultrastructural changes associated with acid activation of Helicobacter pylori vacuolating cytotoxin (VacA). Purified VacA molecules imaged by deep-etch electron microscopy form approximately 30-nm hexagonal "flowers," each composed of an approximately 15-nm central ring surrounded by six approximately 6-nm globular "petals." Upon exposure to acidic pH, these oligomeric flowers dissociate into collections of up to 12 teardrop-shaped subunits, each measuring approximately 6 x 14 nm. Correspondingly, glycerol density gradient centrifugation shows that at neutral pH VacA sediments at approximately 22 S, whereas at acidic pH it dissociates and sediments at approximately 5 S. Immunoblot and EM analysis of the 5-S material demonstrates that it represents approximately 90-kD monomers with 6 x 14-nm "teardrop" morphology. These data indicate that the intact VacA oligomer consists of 12 approximately 90-kD subunits assembled into two interlocked six-membered arrays, overlap of which gives rise to the flower-like appearance. Support for this interpretation comes from EM identification of small numbers of relatively "flat" oligomers composed of six teardrop-shaped subunits, interpreted to be halves of the complete flower. These flat forms adsorb to mica in two different orientations, corresponding to hexameric surfaces that are either exposed or sandwiched inside the dodecamer, respectively. This view of VacA structure differs from a previous model in which the flowers were interpreted to be single layers of six monomers and the flat forms were thought to be proteolysed flowers. Since acidification has been shown to potentiate the cytotoxic effects of VacA, the present results suggest that physical disassembly of the VacA oligomer is an important feature of its activation.


Asunto(s)
Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/metabolismo , Citotoxinas/metabolismo , Helicobacter pylori/metabolismo , Vacuolas/metabolismo , Ácidos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/ultraestructura , Toxinas Bacterianas/química , Tampones (Química) , Citotoxinas/química , Endopeptidasas , Grabado por Congelación , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Hidrólisis , Sustancias Macromoleculares , Microscopía Electrónica , Microscopía por Video
10.
Science ; 256(5060): 1199-202, 1992 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-1317063

RESUMEN

Multifunctional calcium-calmodulin-dependent protein kinase (CaM kinase) transduces transient elevations in intracellular calcium into changes in the phosphorylation state and activity of target proteins. By fluorescence emission anisotropy, the affinity of CaM kinase for dansylated calmodulin was measured and found to increase 1000 times after autophosphorylation of the threonine at position 286 of the protein. Autophosphorylation markedly slowed the release of bound calcium-calmodulin; the release time increased from less than a second to several hundred seconds. In essence, calmodulin is trapped by autophosphorylation. The shift in affinity does not occur in a site-directed mutant in which threonine at position 286 has been replaced by a non-phosphorylatable amino acid. These experiments demonstrate the existence of a new state in which calmodulin is bound to CaM kinase even though the concentration of calcium is basal. Calmodulin trapping provides for molecular potentiation of calcium transients and may enable detection of their frequency.


Asunto(s)
Calmodulina/metabolismo , Proteínas Quinasas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Unión Competitiva , Calcio/farmacología , Proteínas Quinasas Dependientes de Calcio-Calmodulina , Línea Celular , Ácido Egtácico/farmacología , Cinética , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Fosforilación , Unión Proteica , Proteínas Quinasas/genética , Proteínas Recombinantes/metabolismo , Espectrometría de Fluorescencia , Treonina , Factores de Tiempo , Transfección
12.
Equine Vet J ; 41(3): 309-12, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19469242

RESUMEN

REASONS FOR PERFORMING STUDY: Lameness is a highly prevalent condition in horses and the principal cause of removal from athletic activity. In clinical studies to evaluate nonsteroidal anti-inflammatory drug therapies, force plates are commonly used to assess improvement of lameness objectively. HYPOTHESIS: To use a force plate to determine the optimal dose of a new COX-2 inhibitor (firocoxib) that will reduce lameness, when administered orally to horses once daily. METHODS: Sixty-four horses that exhibited chronic lameness presumed due to osteoarthritis, including navicular disease, in at least one of the frontlimbs and at a stable level of severity, were included. Horses were treated per os s.i.d. for 7 days as follows: vehicle control, firocoxib at 0.05, 0.1 or 0.25 mg/kg bwt. Force plate analysis of each horse was done for the selected (most) lame frontlimb at trot. Once between Days -19 and -4 (initial examination), and again on Day -2 or -1 (baseline), pretreatment force plate assessments were performed, and thereafter horses were assessed on Days 0, 2 and 6, approximately 10 h post treatment each time. Peak vertical force (PVF) and lameness grades at initial examination and at baseline, and their change from baseline in the 4 different treatment groups were analysed statistically at a significance level of P < 0.05. RESULTS: The PVF results were found to be superior to vehicle control already at Day 0 for 0.25 mg/kg bwt and at Days 2 and 6 for 0.1 and 0.25 mg/kg bwt (P < 0.05). Mean clinical lameness for both concentrations decreased > 1 grade at Day 6. CONCLUSIONS AND CLINICAL RELEVANCE: With the dosage of 0.25 mg/kg bwt lameness did not improve more than with 0.1 mg/kg bwt. Thus, 0.1 mg/kg bwt s.i.d. was considered to be the effective dose at reducing chronic lameness in horses presumed due to osteoarthritis, including navicular disease.


Asunto(s)
4-Butirolactona/análogos & derivados , Antiinflamatorios no Esteroideos/uso terapéutico , Enfermedades de los Caballos/tratamiento farmacológico , Cojera Animal/tratamiento farmacológico , Sulfonas/uso terapéutico , 4-Butirolactona/administración & dosificación , 4-Butirolactona/uso terapéutico , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Fenómenos Biomecánicos , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Miembro Anterior , Caballos , Masculino , Presión , Sulfonas/administración & dosificación
13.
Neurosci Lett ; 711: 134437, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31422098

RESUMEN

Parkinson's disease (PD) is characterised pathologically by degeneration of the dopaminergic (DA) neurones of the substantia nigra pars compacta (SNpc) and the presence of α-synuclein containing Lewy body inclusions. Trichloroethylene (TCE) has been suggested as a potential environmental chemical that may contribute to the development of PD, via conversion to the neurotoxin, 1-Trichloromethyl-1,2,3,4-tetrahydro-ß-carboline (TaClo). We investigated the effect of an 8 week exposure to TCE or TaClo on wild type and, as an experimental model of PD, A30P mutant α-synuclein overexpressing mice using a combination of behaviour and pathology. TCE or TaClo exposure caused significant DA neuronal loss within the SNpc in both wild type and transgenic mice. Cell numbers were lower in A30P animals than wild type, however, no additive effect of TCE or TaClo exposure and A30P overexpression was found. TCE or TaClo did not appear to lead to acceleration of motor or cognitive deficits in either wild type or A30P mutant mice, potentially because of the modest reductions of DA neuronal number in the SNpc. Our results do however suggest that TCE exposure could be a possible factor in development of PD like changes following exposure.


Asunto(s)
Neuronas Dopaminérgicas/efectos de los fármacos , Degeneración Nerviosa/patología , Neurotoxinas/toxicidad , Trastornos Parkinsonianos/patología , Tricloroetileno/toxicidad , Animales , Neuronas Dopaminérgicas/patología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación , Neurotoxinas/metabolismo , Sustancia Negra/efectos de los fármacos , Sustancia Negra/patología , Tricloroetileno/metabolismo , alfa-Sinucleína/genética
14.
Neuron ; 31(1): 9-12, 2001 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-11498045

RESUMEN

TorsinA is the causative protein in the human neurologic disease early onset torsin dystonia, a movement disorder involving dysfunction in the basal ganglia without apparent neurodegeneration. Most cases result from a dominantly acting three-base pair deletion in the TOR1A gene causing loss of a glutamic acid near the carboxyl terminus of torsinA. Torsins are members of the AAA(+) superfamily of ATPases and are present in all multicellular organisms. Initial studies suggest that torsinA is an ER protein involved in chaperone functions and/or membrane movement.


Asunto(s)
Proteínas Portadoras/genética , Distonía Muscular Deformante/genética , Chaperonas Moleculares , Animales , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Distonía Muscular Deformante/fisiopatología , Humanos , Modelos Moleculares , Familia de Multigenes , Filogenia , Conformación Proteica , Eliminación de Secuencia
15.
Neuron ; 12(5): 943-56, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8185953

RESUMEN

Autophosphorylation of multifunctional Ca2+/calmodulin-dependent protein kinase makes it Ca2+ independent by trapping bound calmodulin and by enabling the kinase to remain partially active even after calmodulin dissociates. We show that autophosphorylation is an intersubunit reaction between neighbors in the multimeric kinase which requires two molecules of calmodulin. Ca2+/calmodulin acts not only to activate the "kinase" subunit but also to present effectively the "substrate" subunit for autophosphorylation. Conversion of the kinase to the potentiated or trapped state is a cooperative process that is inefficient at low occupancy of calmodulin. Simulations show that repetitive Ca2+ pulses at limiting calmodulin lead to the recruitment of calmodulin to the holoenzyme, which further stimulates autophosphorylation and trapping. This cooperative, positive feedback loop will potentiate the response of the kinase to sequential Ca2+ transients and establish a threshold frequency at which the enzyme becomes highly active.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Calcio/metabolismo , Calmodulina/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/biosíntesis , Proteínas Quinasas Dependientes de Calcio-Calmodulina/aislamiento & purificación , Línea Celular , Chlorocebus aethiops , Cinética , Sustancias Macromoleculares , Matemática , Modelos Teóricos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Oligodesoxirribonucleótidos , Fosforilación , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato , Porcinos , Transfección
16.
Neuron ; 3(1): 59-70, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2619995

RESUMEN

Autophosphorylation of multifunctional Ca2+/calmodulin-dependent protein kinase converts it from a Ca2(+)-dependent to a Ca2(+)-independent or autonomous kinase, a process that may underlie some long-term enhancement of transient Ca2+ signals. We demonstrate that the neuronal alpha subunit clone expressed in COS-7 cells (alpha-CaM kinase) is sufficient to encode the regulatory phenomena characteristic of the multisubunit kinase isolated from brain. Activity of alpha-CaM kinase is highly dependent on Ca2+/calmodulin. It is converted by autophosphorylation to an enzyme capable of Ca2(+)-independent (autonomous) substrate phosphorylation and autophosphorylation. Using site-directed mutagenesis, we separately eliminate five putative autophosphorylation sites within the regulatory domain and directly examine their individual roles. Ca2+/calmodulin-dependent kinase activity is fully retained by each mutant, but Thr286 is unique among the sites in being indispensable for generation of an autonomous kinase.


Asunto(s)
Calcio/farmacología , Calmodulina/farmacología , Mutación , Proteínas Quinasas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Encéfalo/enzimología , Proteínas Quinasas Dependientes de Calcio-Calmodulina , Línea Celular , Clonación Molecular , Homeostasis , Cinética , Datos de Secuencia Molecular , Fosforilación , Proteínas Quinasas/genética
17.
Neuron ; 21(1): 99-110, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9697855

RESUMEN

In this study, we demonstrate specific interaction of the GluR2 alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit C-terminal peptide with an ATPase N-ethylmaleimide-sensitive fusion protein (NSF) and alpha- and beta-soluble NSF attachment proteins (SNAPs), as well as dendritic colocalization of these proteins. The assembly of the GluR2-NSF-SNAP complex is ATP hydrolysis reversible and resembles the binding of NSF and SNAP with the SNAP receptor (SNARE) membrane fusion apparatus. We provide evidence that the molar ratio of NSF to SNAP in the GluR2-NSF-SNAP complex is similar to that of the t-SNARE syntaxin-NSF-SNAP complex. NSF is known to disassemble the SNARE protein complex in a chaperone-like interaction driven by ATP hydrolysis. We propose a model in which NSF functions as a chaperone in the molecular processing of the AMPA receptor.


Asunto(s)
Adenosina Trifosfato/fisiología , Proteínas Portadoras/fisiología , Proteínas de la Membrana/fisiología , Receptores AMPA/fisiología , Proteínas de Transporte Vesicular , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/farmacología , Secuencia de Aminoácidos , Animales , Precipitación Química , Dendritas/metabolismo , Interacciones Farmacológicas , Proteínas Sensibles a N-Etilmaleimida , Neuronas/metabolismo , Proteínas Qa-SNARE , Ratas , Ratas Sprague-Dawley , Proteínas Solubles de Unión al Factor Sensible a la N-Etilmaleimida , Levaduras/genética
18.
J Neurol Neurosurg Psychiatry ; 79(10): 1186-9, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18796596

RESUMEN

TAR DNA binding protein-43 (TDP-43) is found in ubiquitinated inclusions (UBIs) in some frontotemporal dementias (FTD-U). One form of FTD-U, due to mutations in the valosin containing protein (VCP) gene, occurs with an inclusion body myopathy (IBMPFD). Since IBMPFD brain has TDP-43 in UBIs, we looked for TDP-43 inclusions in IBMPFD muscle. In normal muscle, TDP-43 is present in nuclei. In IBMPFD muscle, TDP-43 is additionally present as large inclusions within UBIs in muscle cytoplasm. TDP-43 inclusions were also found in 78% of sporadic inclusion body myositis (sIBM) muscles. In IBMPFD and sIBM muscle, TDP-43 migrated with an additional band on immunoblot similar to that reported in FTD-U brains. This study adds sIBM and hereditary inclusion body myopathies to the growing list of TDP-43 positive inclusion diseases.


Asunto(s)
Proteínas de Unión al ADN/inmunología , Demencia , Miositis por Cuerpos de Inclusión , Adenosina Trifosfatasas/genética , Antígenos CD8/inmunología , Proteínas de Ciclo Celular/genética , Demencia/inmunología , Demencia/patología , Demencia/fisiopatología , Diagnóstico Diferencial , Electromiografía , Humanos , Músculo Esquelético/inmunología , Músculo Esquelético/inervación , Músculo Esquelético/patología , Mutación Missense/genética , Miositis por Cuerpos de Inclusión/inmunología , Miositis por Cuerpos de Inclusión/patología , Miositis por Cuerpos de Inclusión/fisiopatología , Fosforilación , Mutación Puntual/genética , Proteína que Contiene Valosina
19.
Neurophysiol Clin ; 38(4): 227-33, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18662619

RESUMEN

OBJECTIVE: To assess and compare, clinically and electrophysiologically, the effects on muscle innervation and spasticity of selective anaesthetic nerve block and selective neurotomy of the motor-nerve branch to the soleus muscle in patients with spastic equinus foot. METHODS: Eleven hemiplegic patients were studied before and after anaesthetic tibial-nerve block, and at two months and one year after tibial nerve neurotomy. Triceps surae spasticity and strength, walking speed, gait kinematics of the ankle, maximal amplitude of the H reflex and of the M-response and the Hmax/Mmax ratio of the soleus muscle, and the mean motor unit action potential area and motor unit number estimation (MUNE) of the soleus muscle were calculated on the normal and spastic side. RESULTS: Spasticity and equinovarus improved in a similar fashion after tibial nerve block and neurotomy. The soleus Hmax/Mmax ratio decreased by 42% after tibial nerve block and 77% after neurotomy. The soleus MUNE decreased by 52% after tibial nerve block and by 86% after neurotomy. CONCLUSION: Diagnostic nerve block predicts the spasticity and gait improvement, which is expected after neurotomy. The clinical improvement was similar after block and neurotomy. Nerve block is associated with a 50% decrease in the soleus Hmax/Mmax ratio and soleus MUNE. The median 80% neurotomy is associated with an 80% decrease in the soleus Hmax/Mmax ratio and soleus MUNE.


Asunto(s)
Deformidades Adquiridas del Pie/fisiopatología , Reflejo H/fisiología , Neuronas Motoras/fisiología , Fibras Musculares Esqueléticas/fisiología , Espasticidad Muscular/fisiopatología , Músculo Esquelético/fisiopatología , Bloqueo Nervioso , Nervio Tibial , Potenciales de Acción/fisiología , Adulto , Fenómenos Biomecánicos , Electrofisiología , Femenino , Marcha , Hemiplejía/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/inervación , Estudios Prospectivos
20.
Ann Readapt Med Phys ; 51(4): 301-14, 2008 May.
Artículo en Inglés, Francés | MEDLINE | ID: mdl-18502531

RESUMEN

PURPOSE: To describe the diagnosis and treatment of adhesive capsulitis of the hip (ACH). METHOD: A literature review and consideration of three case reports. DISCUSSION: Adhesive capsulitis of the hip is a supposedly rare but probably underestimated condition which predominantly affects middle-aged women. Clinical assessment reveals a painful limitation of joint mobility. The diagnosis is confirmed by arthrography, where the crucial factor is a joint capacity below 12ml. Osteoarthritis and complex regional pain syndrome type 1 are the two main differential diagnoses. Whether the treatment is pharmacological, physical or surgical depends on the aetiology of the condition. Physiotherapy is essential for limiting residual deficits and functional impairments. CONCLUSION: Adhesive capsulitis of the hip is probably more common than suggested by the limited medical literature. The condition is frequently idiopathic but can be secondary to another joint pathology. The first-line treatment consists of sustained-release corticosteroid intra-articular injections and physical therapy. Arthroscopy and manipulation under anaesthesia may be useful in cases of ACH which are refractory to treatment.


Asunto(s)
Bursitis/diagnóstico , Bursitis/terapia , Articulación de la Cadera/fisiopatología , Adulto , Anciano , Bursitis/fisiopatología , Diagnóstico Diferencial , Femenino , Articulación de la Cadera/diagnóstico por imagen , Humanos , Masculino , Radiografía
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