Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Nat Commun ; 14(1): 8345, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38102152

RESUMEN

Bioenergetic failure caused by impaired utilisation of glucose and fatty acids contributes to organ dysfunction across multiple tissues in critical illness. Ketone bodies may form an alternative substrate source, but the feasibility and safety of inducing a ketogenic state in physiologically unstable patients is not known. Twenty-nine mechanically ventilated adults with multi-organ failure managed on intensive care units were randomised (Ketogenic n = 14, Control n = 15) into a two-centre pilot open-label trial of ketogenic versus standard enteral feeding. The primary endpoints were assessment of feasibility and safety, recruitment and retention rates and achievement of ketosis and glucose control. Ketogenic feeding was feasible, safe, well tolerated and resulted in ketosis in all patients in the intervention group, with a refusal rate of 4.1% and 82.8% retention. Patients who received ketogenic feeding had fewer hypoglycaemic events (0.0% vs. 1.6%), required less exogenous international units of insulin (0 (Interquartile range 0-16) vs.78 (Interquartile range 0-412) but had slightly more daily episodes of diarrhoea (53.5% vs. 42.9%) over the trial period. Ketogenic feeding was feasible and may be an intervention for addressing bioenergetic failure in critically ill patients. Clinical Trials.gov registration: NCT04101071.


Asunto(s)
Enfermedad Crítica , Cetosis , Adulto , Humanos , Proyectos Piloto , Unidades de Cuidados Intensivos , Cuerpos Cetónicos
2.
PLoS One ; 18(12): e0289719, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38134136

RESUMEN

BACKGROUND: Labile blood pressure after acute ischaemic stroke requiring mechanical thrombectomy is independently associated with poor patient outcomes. OBJECTIVES: This study protocol describes is designed to determine whether transauricular nerve stimulation, improves baroreflex sensitivity, reduces blood pressure variability in the first 24 hours after acute ischaemic stroke requiring mechanical thrombectomy. DESIGN: PHASE 2A, PROOF-OF-CONCEPT, SHAM-CONTROLLED RANDOMISED TRIAL: Methods and Analysis: 36 individuals undergoing mechanical thrombectomy for acute ischaemic stroke with established hypertension aged >18 years will be randomly allocated to receive bilateral active or sham transauricular nerve stimulation for the duration of the mechanical thrombectomy procedure (AffeX-CT/001 investigational device). The intervention will be repeated for 1h the morning following the mechanical thrombectomy. Non-invasive blood pressure will be measured ≥2h for 24h after mechanical thrombectomy. Holter electrocardiographic monitoring will be recorded during transauricular nerve stimulation. Participants, clinicians and investigators will be masked to treatment allocations. The primary outcome will be the coefficient of variation of systolic blood pressure. Secondary outcomes include additional estimates of blood pressure variability and time/frequency-domain measures of autonomic cardiac modulation An adjusted sample size of 36 patients is required to have a 90% chance of detecting, as significant at the 5% level, a difference in the coefficient of variation in systolic blood pressure of 5±4mmHg between sham and active stimulation [assuming 5% non-compliance rate in each group]. Ethics: confirmed on 16 March 2023 by HRA and Health and Care Research Wales ethics committee (reference 23/WA/0013). DISCUSSION: This study will provide proof-of-concept data that examines whether non-invasive autonomic neuromodulation can be used to favourably modify blood pressure and autonomic control after acute ischaemic stroke requiring mechanical thrombectomy. TRIAL REGISTRATION: Trial registration number: NCT05417009.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/terapia , Accidente Cerebrovascular/complicaciones , Isquemia Encefálica/terapia , Isquemia Encefálica/complicaciones , Resultado del Tratamiento , Accidente Cerebrovascular Isquémico/complicaciones , Trombectomía , Ensayos Clínicos Controlados Aleatorios como Asunto , Ensayos Clínicos Fase II como Asunto
3.
J Alzheimers Dis ; 94(1): 347-357, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37248895

RESUMEN

BACKGROUND: Identification of older individuals with increased risk for cognitive decline can contribute not only to personal benefits (e.g., early treatment, evaluation of treatment), but could also benefit clinical trials (e.g., patient selection). We propose that baseline resting-state electroencephalography (rsEEG) could provide markers for early identification of cognitive decline. OBJECTIVE: To determine whether rsEEG theta/beta ratio (TBR) differed between mild cognitively impaired (MCI) and healthy older adults. METHODS: We analyzed rsEEG from a sample of 99 (ages 60-90) consensus-diagnosed, community-dwelling older African Americans (58 cognitively typical and 41 MCI). Eyes closed rsEEGs were acquired before and after participants engaged in a visual motion direction discrimination task. rsEEG TBR was calculated for four midline locations and assessed for differences as a function of MCI status. Hemispheric asymmetry of TBR was also analyzed at equidistant lateral electrode sites. RESULTS: Results showed that MCI participants had a higher TBR than controls (p = 0.04), and that TBR significantly differed across vertex location (p < 0.001) with the highest TBR at parietal site. MCI and cognitively normal controls also differed in hemispheric asymmetries, such that MCI show higher TBR at frontal sites, with TBR greater over right frontal electrodes in the MCI group (p = 0.003) and no asymmetries found in the cognitively normal group. Lastly, we found a significant task aftereffect (post-task compared to pre-task measures) with higher TBR at posterior locations (Oz p = 0.002, Pz p = 0.057). CONCLUSION: TBR and TBR asymmetries differ between MCI and cognitively normal older adults and may reflect neurodegenerative processes underlying MCI symptoms.


Asunto(s)
Negro o Afroamericano , Disfunción Cognitiva , Electroencefalografía , Anciano , Humanos , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etnología , Electroencefalografía/métodos , Descanso , Anciano de 80 o más Años , Ritmo Teta , Ritmo beta , Vida Independiente
4.
J Environ Qual ; 52(3): 596-609, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36746193

RESUMEN

Canada's livestock production and human populations are concentrated in southern regions. Understanding spatial and temporal distributions of animals and excreted nutrients is key to optimizing manure resources and minimizing impact of livestock. Here, we identify manureshed concerns and opportunities by reconciling nitrogen supply and demand on a regional and national scale. Data based on national statistics and farm surveys were allocated to homogeneous soil polygons (Soil Landscapes of Canada [SLC]) to quantify changes in nutrient distribution and ammonia (NH3 ) emissions across Canada (1981-2018). Livestock sectors tied to domestic consumption, dairy and poultry, were stable over time and well dispersed. Export driven beef production has moved west since 1981, whereas pig production was prominent in Manitoba, Quebec, and Ontario. Per ha manure N excretion across livestock sectors in 2018 was generally low with 58% and 6% of the SLCs averaging <25 and >100 kg N ha-1 , respectively. Although only 3% of SLCs had average NH3 emissions reaching 16-200 kg ha-1 , most of these were located near cities and emissions spiked in spring when more people might be exposed. The greatest concentrations of nutrients and livestock occurred around the three largest metropolitan areas: Toronto, Montreal-Quebec City, and Vancouver, posing challenges for nutrient recycling and public health. This study shows that as Canadian cities and livestock agriculture grow in southern Canada, so will challenges around food production, human health, and managing nutrients. Livestock and land use strategies are needed to reconcile changing animal sectors and growing populations.


Asunto(s)
Ganado , Estiércol , Bovinos , Animales , Porcinos , Humanos , Canadá , Suelo , Agricultura , Nitrógeno/análisis
5.
Int J Psychophysiol ; 177: 213-219, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35618112

RESUMEN

BACKGROUND: Finding the baseline resting-state EEG markers for early identification of cognitive decline can contribute to the identification of individuals at risk of further change. Potential applications include identifying participants for clinical trials, early treatment, and evaluation of treatment, accessible even from a community setting. METHODS: Analyses were completed on a sample of 99 (ages 60-90) consensus-diagnosed, community-dwelling African Americans (58 cognitively typical/HC, and 41 mildly cognitively impaired/MCI), who were recruited from the Michigan Alzheimer's Disease Research Center (MADRC) and the Wayne State University Institute of Gerontology. In addition to neuropsychological testing with CogState and Toolbox computerized batteries, resting-state EEGs (rsEEG, eyes closed) were acquired before and after participants were engaged in a visual motion direction discrimination task. rsEEG frontal alpha asymmetry (FAA) and frontal beta asymmetry (FBA) were calculated. RESULTS: FAA showed no difference across groups for the pre-task resting state. FBA was significantly different between groups, with more asymmetric frontal beta in MCI. Both physiological indices, however, along with computerized neuropsychological tests were significant predictors in logistic regression classification of MCI vs. control participants. CONCLUSION: rsEEG asymmetries can contribute significantly to successful discrimination of older persons with MCI from those without, over and above cognitive testing, alone.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Anciano , Anciano de 80 o más Años , Disfunción Cognitiva/diagnóstico , Electroencefalografía , Humanos , Persona de Mediana Edad , Pruebas Neuropsicológicas , Descanso/fisiología
6.
Front Aging Neurosci ; 14: 1061254, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36711212

RESUMEN

The view of the human brain as a complex network has led to considerable advances in understanding the brain's network organization during rest and task, in both health and disease. Here, we propose that examining brain networks within the task aftereffect model, in which we compare resting-state networks immediately before and after a cognitive engagement task, may enhance differentiation between those with normal cognition and those with increased risk for cognitive decline. We validated this model by comparing the pre- and post-task resting-state functional network organization of neurologically intact elderly and those with mild cognitive impairment (MCI) derived from electroencephalography recordings. We have demonstrated that a cognitive task among MCI patients induced, compared to healthy controls, a significantly higher increment in global network integration with an increased number of vertices taking a more central role within the network from the pre- to post-task resting state. Such modified network organization may aid cognitive performance by increasing the flow of information through the most central vertices among MCI patients who seem to require more communication and recruitment across brain areas to maintain or improve task performance. This could indicate that MCI patients are engaged in compensatory activation, especially as both groups did not differ in their task performance. In addition, no significant group differences were observed in network topology during the pre-task resting state. Our findings thus emphasize that the task aftereffect model is relevant for enhancing the identification of network topology abnormalities related to cognitive decline, and also for improving our understanding of inherent differences in brain network organization for MCI patients, and could therefore represent a valid marker of cortical capacity and/or cortical health.

7.
Head Neck Pathol ; 15(4): 1391-1398, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33616852

RESUMEN

Clear Cell odontogenic Carcinomas (CCOC) are rare, aggressive malignant odontogenic tumours which are often misdiagnosed as benign odontogenic tumours due to the non-specific histologic appearance, and benign early clinical presentation. However, due to their propensity to metastasize, the best outcomes are experienced with they are diagnosed early and treated aggressively. In this paper, we present a case of a CCOC misdiagnosed as a clear cell calcifying epithelial odontogenic tumour which was only found to be a CCOC after cervical node metastasis. The original diagnosis was questioned and confirmed to be a CCOC by identification of the chromosomal translocation EWSR1 on fluorescence in situ hybridization. This has recently been described in CCOC and a wide variety of other mesenchymal and epithelial neoplasms. Previous reports have demonstrated EWSR1-ATF1 and EWSR1-CREB1 fusions in CCOC. Next generation sequencing of this case demonstrated the EWSR1-CREM fusion gene which has not been previously reported for CCOC. CREM fusion proteins have only recently been found in several tumour types including the closely associated hyalinizing clear cell carcinoma of salivary glands. This is discussed in this paper, and the role of the discovery of the CREM fusion protein in CCOC adds to your understating of the role of CREM in oncogenesis, and the possible link between CCOCs and hyalinizing clear cell carcinomas.


Asunto(s)
Modulador del Elemento de Respuesta al AMP Cíclico/genética , Neoplasias Maxilares/diagnóstico , Neoplasias Maxilares/genética , Tumores Odontogénicos/diagnóstico , Tumores Odontogénicos/genética , Proteína EWS de Unión a ARN/genética , Biomarcadores de Tumor/análisis , Diagnóstico Diferencial , Resultado Fatal , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hibridación Fluorescente in Situ , Hallazgos Incidentales , Imagen por Resonancia Magnética , Masculino , Neoplasias Maxilares/patología , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Tumores Odontogénicos/patología , Tomografía Computarizada por Rayos X
8.
Psychol Res ; 85(2): 660-678, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32020364

RESUMEN

The possibility that interference between motor responses contributes to dual-task costs has long been neglected, yet is supported by several recent studies. There are two competing hypotheses regarding this response-related interference. The motor-bottleneck hypothesis asserts that the motor stage of Task 1 triggers a refractory period that delays the motor stage of Task 2. The response-monitoring hypothesis asserts that monitoring of the Task-1 motor response delays the response-selection stage of Task 2. Both hypotheses predict lengthening of Task-2 response time (RT2) when Task 1 requires motor processing relative to when it does not. However, they assume different loci for the response-related bottleneck, and therefore make different predictions regarding (a) the interaction between Task-1 motor requirement and the Task-2 difficulty effect as measured by RT2 and (b) the premotoric durations and motoric durations of Task 2 as measured by lateralized readiness potentials (LRPs). To test these predictions, we conducted two experiments manipulating the Task-1 motor requirement (Go vs. NoGo) and Task-2 response-selection difficulty, as well as the stimulus-onset asynchrony (SOA). Task-1 motor processing significantly lengthened RT2, suggesting response-related interference. Importantly, the Task-1 motor response reduced the Task-2 difficulty effect at the short SOA, indicating postponement of the Task-2 motor stage, consistent with the motor-bottleneck hypothesis. Further consistent with the motor-bottleneck hypothesis, the Task-2 LRP indicated a consistent premotoric duration of Task 2 regardless of Task-1 motor requirement. These results are difficult to reconcile with the response-monitoring hypotheses, which places the response-related bottleneck before the response-selection stage of Task 2. The results also have important implications regarding use of locus-of-slack logic in PRP studies.


Asunto(s)
Atención/fisiología , Conducta de Elección/fisiología , Enmascaramiento Perceptual/fisiología , Periodo Refractario Psicológico/fisiología , Adulto , Femenino , Humanos , Masculino , Tiempo de Reacción/fisiología , Adulto Joven
9.
Ecol Evol ; 10(16): 8592-8609, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32884643

RESUMEN

Reliable age estimation is an essential tool to assess the status of wildlife populations and inform successful management. Aging methods, however, are often limited by too few data, skewed demographic representation, and by single or uncertain morphometric relationships. In this study, we synthesize age estimates in southern sea otters Enhydra lutris nereis from 761 individuals across 34 years of study, using multiple noninvasive techniques and capturing all life stages from 0 to 17 years of age. From wild, stranded, and captive individuals, we describe tooth eruptions, tooth wear, body length, nose scarring, and pelage coloration across ontogeny and fit sex-based growth functions to the data. Dental eruption schedules provided reliable and identifiable metrics spanning 0.3-9 months. Tooth wear was the most reliable predictor of age of individuals aged 1-15 years, which when combined with total length, explained >93% of observed age. Beyond age estimation, dental attrition also indicated the maximum lifespan of adult teeth is 13‒17 years, corresponding with previous estimates of life expectancy. Von Bertalanffy growth function model simulations of length at age gave consistent estimates of asymptotic lengths (male Loo  = 126.0‒126.8 cm, female Loo  = 115.3‒115.7 cm), biologically realistic gestation periods (t 0 = 115 days, SD = 10.2), and somatic growth (male k = 1.8, SD = 0.1; female k = 2.1, SD = 0.1). Though exploratory, we describe how field radiographic imaging of epiphyseal plate development or fusions may improve aging of immature sea otters. Together, our results highlight the value of integrating information from multiple and diverse datasets to help resolve conservation problems.

10.
Ecol Evol ; 10(7): 3318-3329, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32273989

RESUMEN

The sea otter (Enhydra lutris) is a marine mammal hunted to near extinction during the 1800s. Despite their well-known modern importance as a keystone species, we know little about historical sea otter ecology. Here, we characterize the ecological niche of ancient southern sea otters (E. lutris nereis) using δ13C analysis and δ15N analysis of bones recovered from archaeological sites spanning ~7,000 to 350 years before present (N = 112 individuals) at five regions along the coast of California. These data are compared with previously published data on modern animals (N = 165) and potential modern prey items. In addition, we analyze the δ15N of individual amino acids for 23 individuals to test for differences in sea otter trophic ecology through time. After correcting for tissue-specific and temporal isotopic effects, we employ nonparametric statistics and Bayesian niche models to quantify differences among ancient and modern animals. We find ancient otters occupied a larger isotopic niche than nearly all modern localities; likely reflecting broader habitat and prey use in prefur trade populations. In addition, ancient sea otters at the most southerly sites occupied an isotopic niche that was more than twice as large as ancient otters from northerly regions. This likely reflects greater invertebrate prey diversity in southern California relative to northern California. Thus, we suggest the potential dietary niche of sea otters in southern California could be larger than in central and northern California. At two sites, Año Nuevo and Monterey Bay, ancient otters had significantly higher δ15N values than modern populations. Amino acid δ15N data indicated this resulted from shifting baseline isotope values, rather than a change in sea otter trophic ecology. Our results help in better understanding the contemporary ecological role of sea otters and exemplify the strength of combing zooarchaeological and biological information to provide baseline data for conservation efforts.

12.
J Oral Pathol Med ; 48(3): 206-213, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30576014

RESUMEN

BACKGROUND: Recurrence of oral squamous cell carcinoma (rOSCC) after primary treatment is associated with poor survival outcomes. Salvage treatment with further surgery, radiotherapy and chemotherapy has high morbidity, making patient selection crucial. However, in the recurrence setting, reliable stratification data are scarce. Decision-making in this context is consequently complex. We investigated factors influencing overall survival after rOSCC. METHODS: Retrospective cohort study of patients with rOSCC (n = 83) at the Queen Elizabeth Hospital Birmingham, UK between 2006 and 2016. Associations with overall survival were analysed using univariate and multivariate analyses to identify important clinical prognostic indicators. RESULTS: Overall survival at 1 year was 32.5% and at 5 years was 18.1% after a median follow-up of 7.4 months. Multivariate analysis identified four independent predictors of overall survival following rOSCC: size of primary tumour (HR 2.077; 95% CI 1.034-4.172), extent of recurrent disease (HR 3.286; 95% CI 1.545-6.991), history of moderate alcohol consumption (HR 0.351; 95% CI 0.162-0.763), and close or positive margins at primary resection (HR 1.955; 95% CI 1.063-3.595). CONCLUSIONS: We identified four key factors that help prognostication and risk stratification of rOSCC. Given the high morbidity associated with salvage treatment, we recommend that the multidisciplinary team (MDT) and the patient weigh these factors carefully when considering further treatment. Further investigation of the biology underlying these oncophenotypes may contribute to better patient stratification.


Asunto(s)
Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/terapia , Neoplasias de la Boca/mortalidad , Neoplasias de la Boca/terapia , Recurrencia Local de Neoplasia , Adulto , Anciano , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas/efectos adversos , Análisis de Varianza , Estudios de Cohortes , Femenino , Humanos , Masculino , Márgenes de Escisión , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Terapia Recuperativa , Tasa de Supervivencia , Factores de Tiempo , Fumar Tabaco/efectos adversos , Reino Unido/epidemiología
13.
Craniomaxillofac Trauma Reconstr ; 10(2): 117-122, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28523085

RESUMEN

Bony reconstruction of the mandible after surgical resection results in improved rehabilitation and aesthetics. Composite tissue transfer has transformed reconstruction, particularly in patients who have received radiotherapy. However, there is morbidity related to free tissue transfer. Free nonvascularized bone grafts have much lower morbidity. Surgeons believe that free bone grafts greater than 6.0 cm are prone to failure. The aims of this study was to assess whether bone grafts greater than 6.0 cm in length have a high risk of failure. A retrospective study was performed on all patients who had free bone grafts greater than 6.0 cm in length at Birmingham, UK, and Florida, the United States. None of the patients received radiotherapy. A total of 14 patients had undergone bone grafts for mandibular defects greater than 6.0 cm in length; 13 of the bone grafts were successful. Of these 13, none were infected and there was radiographic evidence of bony union. Some of the patients have been dentally rehabilitated with implants. Contrary to much of the literature and many surgeons belief, our study has shown that long mandibular defects (>6.0 cm) are not a contraindication to the use of free bone grafts. Key principles to achieve success are discussed in this article.

14.
Sensors (Basel) ; 17(3)2017 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-28287483

RESUMEN

In the following paper, we present an industry perspective of inertial sensors for navigation purposes driven by applications and customer needs. Microelectromechanical system (MEMS) inertial sensors have revolutionized consumer, automotive, and industrial applications and they have started to fulfill the high end tactical grade performance requirements of hybrid navigation systems on a series production scale. The Fiber Optic Gyroscope (FOG) technology, on the other hand, is further pushed into the near navigation grade performance region and beyond. Each technology has its special pros and cons making it more or less suitable for specific applications. In our overview paper, we present latest improvements at NG LITEF in tactical and navigation grade MEMS accelerometers, MEMS gyroscopes, and Fiber Optic Gyroscopes, based on our long-term experience in the field. We demonstrate how accelerometer performance has improved by switching from wet etching to deep reactive ion etching (DRIE) technology. For MEMS gyroscopes, we show that better than 1°/h series production devices are within reach, and for FOGs we present how limitations in noise performance were overcome by signal processing. The paper also intends a comparison of the different technologies, emphasizing suitability for different navigation applications, thus providing guidance to system engineers.

15.
Pediatr Clin North Am ; 63(3): 525-38, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27261548

RESUMEN

Effective patient-provider communication is not a primary focus of medical school curricula. Motivational interviewing (MI) is a patient-centered, directive communication framework appropriate for in health care. Research on MI's causal mechanisms has established patient change talk as a mediator of behavior change. Current MI research focuses on identifying which provider communication skills are responsible for evoking change talk. MI recommends informing, asking, and listening. Research provides evidence that asking for and reflecting patient change talk are effective communication strategies, but cautions providers to inform judiciously. Supporting a patient's decision making autonomy is an important strategy to promote health behaviors.


Asunto(s)
Consejo , Entrevista Motivacional/métodos , Obesidad Infantil/terapia , Relaciones Profesional-Paciente , Adolescente , Niño , Protección a la Infancia/tendencias , Femenino , Humanos , Masculino , Educación del Paciente como Asunto , Obesidad Infantil/complicaciones , Evaluación de Programas y Proyectos de Salud , Estados Unidos
16.
Int J Psychophysiol ; 96(3): 125-33, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25889693

RESUMEN

The slowing of information processing, a hallmark of cognitive aging, has several origins. Previously we reported that in a motion direction discrimination task, older as compared to younger participants showed prolonged non-decision time, an index of an early perceptual stage, while in motion onset visual evoked potentials (MO-VEPs) the P1 component was enhanced and N2 was diminished. We did not find any significant correlations between behavioral and MO-VEP measures. Here, we investigated the role of age in encoding and perceptual processing of stimulus onset visually evoked potentials (SO-VEPs). Twelve healthy adults (age<55years) and 19 elderly (age>55years) performed a motion direction discrimination task during EEG recording. Prior to motion, the stimulus consisted of a static cloud of white dots on a black background. As expected, SO-VEPs evoked well defined P1, N1, and P2 components. Elderly participants as compared to young participants showed increased P1 amplitude while their P2 amplitude was reduced. In addition elderly participants showed increased latencies for P1 and N1 components. Contrary to the findings with MO-VEPs, SO-VEP parameters were significant predictors of average response times and diffusion model parameters. Our electrophysiological results support the notion that slowing of information processing in older adults starts at the very beginning of encoding in visual cortical processing, most likely in striate and extrastriate visual cortices. More importantly, the earliest SO-VEP components, possibly reflecting configuration of visual cortices and encoding processes, predict subsequent prolonging and tardiness of perceptual and higher-level cognitive processes.


Asunto(s)
Corteza Cerebral/fisiología , Discriminación en Psicología/fisiología , Potenciales Evocados Visuales/fisiología , Movimiento (Física) , Orientación , Percepción del Tiempo/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estimulación Luminosa , Tiempo de Reacción , Estadística como Asunto , Estadísticas no Paramétricas , Adulto Joven
17.
Neuropsychologia ; 68: 82-93, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25575450

RESUMEN

Partial cortical blindness is a visual deficit caused by unilateral damage to the primary visual cortex, a condition previously considered beyond hopes of rehabilitation. However, recent data demonstrate that patients may recover both simple and global motion discrimination following intensive training in their blind field. The present experiments characterized motion-induced neural activity of cortically blind (CB) subjects prior to the onset of visual rehabilitation. This was done to provide information about visual processing capabilities available to mediate training-induced visual improvements. Visual Evoked Potentials (VEPs) were recorded from two experimental groups consisting of 9 CB subjects and 9 age-matched, visually-intact controls. VEPs were collected following lateralized stimulus presentation to each of the 4 visual field quadrants. VEP waveforms were examined for both stimulus-onset (SO) and motion-onset (MO) related components in postero-lateral electrodes. While stimulus presentation to intact regions of the visual field elicited normal SO-P1, SO-N1, SO-P2 and MO-N2 amplitudes and latencies in contralateral brain regions of CB subjects, these components were not observed contralateral to stimulus presentation in blind quadrants of the visual field. In damaged brain hemispheres, SO-VEPs were only recorded following stimulus presentation to intact visual field quadrants, via inter-hemispheric transfer. MO-VEPs were only recorded from damaged left brain hemispheres, possibly reflecting a native left/right asymmetry in inter-hemispheric connections. The present findings suggest that damaged brain hemispheres contain areas capable of responding to visual stimulation. However, in the absence of training or rehabilitation, these areas only generate detectable VEPs in response to stimulation of the intact hemifield of vision.


Asunto(s)
Ceguera Cortical/fisiopatología , Electroencefalografía/métodos , Potenciales Evocados Visuales/fisiología , Lateralidad Funcional/fisiología , Percepción de Movimiento/fisiología , Corteza Visual/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Campos Visuales/fisiología
18.
Br J Oral Maxillofac Surg ; 52(2): 106-10, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24315201

RESUMEN

We retrospectively audited operative complications, success of flaps, and speech and swallowing outcomes in patients with head and neck cancer who had reconstruction with jejunal free tissue transfer to the pharynx. A total of 104 patients had jejunal free flaps between 1987 and 2009 at University Hospital, Birmingham. Management was by a multidisciplinary team, and the same vascular surgeon did all the anastomoses. We investigated the relations between patients, operative factors, and postoperative complications, and noted the ischaemic time of the flaps and coexisting conditions of the patients. Outcomes measured included initial and final survival rates of flaps, donor and recipient site complications, and speech and swallowing outcomes on discharge and up to 2 years postoperatively. Of the 104 patients, 14 (13%) had initial flap complications but overall flap survival was 97%. A total of 11 (11%) patients developed a fistula at a mean of 15 days postoperatively and 11 (11%) had minor donor site complications. A total of 95 (91%) were able to resume oral diet on discharge. Of the 44 who were followed up on discharge, 32 (73%) were able to maintain oral intake at 2 years and 31 (70%) could use their voice in everyday situations. The jejunal free flap enables the tumour to be removed, and reconstruction and restoration of function to be done in a single operation using tissue that is versatile. The operation is associated with low morbidity at the donor and recipient sites, and results in good speech and swallowing outcomes. The flap can also be used to reconstruct pharyngolaryngeal defects.


Asunto(s)
Colgajos Tisulares Libres/trasplante , Neoplasias de Cabeza y Cuello/cirugía , Yeyuno/trasplante , Faringe/cirugía , Procedimientos de Cirugía Plástica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Anastomosis Quirúrgica/métodos , Carcinoma de Células Escamosas/cirugía , Fístula Cutánea/etiología , Deglución/fisiología , Femenino , Fístula/etiología , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Masculino , Auditoría Médica , Persona de Mediana Edad , Enfermedades Faríngeas/etiología , Complicaciones Posoperatorias , Estudios Retrospectivos , Habla/fisiología , Resultado del Tratamiento , Calidad de la Voz/fisiología , Isquemia Tibia
19.
J Dev Behav Pediatr ; 34(8): 599-608, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24131883

RESUMEN

OBJECTIVE: The goal of this research was to identify communication behaviors used by weight loss counselors that mostly strongly predicted black adolescents' motivational statements. Three types of motivational statements were of interest: change talk (CT; statements describing their own desires, abilities, reasons, and need for adhering to weight loss recommendations), commitment language (CML; statements about their intentions or plans for adhering), and counterchange talk (CCT; amotivational statements against change and commitment). METHODS: Thirty-seven black adolescents with obesity received a single motivational interviewing session targeting weight-related behaviors. The video-recorded transcribed sessions were coded using the Minority Youth Sequential Coding for Observing Process Exchanges generating a sequential chain of communication. Data were then subjected to sequential analysis to determine causal relationships between counselor and adolescent communication. RESULTS: Asking open-ended questions to elicit adolescent CT and emphasizing adolescents' autonomy most often led to CT. Open-ended questions to elicit CML, reflecting adolescent CML, and emphasizing autonomy most often led to CML. In contrast, open-ended questions to elicit CCT, reflecting CCT, reflecting ambivalence, and neutral open-ended questions about the target behavior led to CCT. CONCLUSIONS: This study provides clinicians with insight into the most effective way to communicate with black adolescents with obesity about weight loss. Specifically, reflective statements and open questions focusing on their own desires, abilities, reasons, need, and commitment to weight loss recommendations are more likely to increase motivational statements, whereas other types of reflections and questions may be counterproductive. Finally, because adolescents have a strong need for autonomous decision making, emphasizing their autonomy may be particularly effective in evoking motivational statements.


Asunto(s)
Negro o Afroamericano/psicología , Comunicación , Consejo/normas , Entrevista Motivacional/normas , Obesidad Infantil/psicología , Relaciones Profesional-Paciente , Adolescente , Conducta del Adolescente/etnología , Conducta del Adolescente/psicología , Negro o Afroamericano/etnología , Cuidadores , Niño , Femenino , Humanos , Masculino , Michigan/etnología , Entrevista Motivacional/métodos , Obesidad Infantil/etnología , Programas de Reducción de Peso/métodos , Programas de Reducción de Peso/normas , Recursos Humanos
20.
Cornea ; 32(12): 1567-77, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24162748

RESUMEN

PURPOSE: The aim was to assess the visual impact of ocular wavefront aberrations, corneal thickness, and corneal light scatter prospectively after performing a Descemet stripping automated endothelial keratoplasty (DSAEK) in humans. METHODS: Data were obtained prospectively from 20 eyes preoperatively and at 1, 3, 6, and 12 months post-DSAEK. At each visit, the best spectacle-corrected visual acuity and visual acuity with glare (brightness acuity testing) were recorded, and ocular wavefront measurements and corneal optical coherence tomography (OCT) were performed. The magnitude and the sign of individual Zernike terms [higher-order aberrations (HOAs)] were determined. Epithelial, host stromal, donor stromal, and total corneal thicknesses were quantified. The brightness and intensity profiles of OCT images were generated to quantify light scatter in the whole cornea, subepithelial region, anterior and posterior host stroma, interface, and donor stroma. RESULTS: The mean best spectacle-corrected visual acuity and glare disability at low light levels improved from 1 to 12 months post-DSAEK. All corneal thicknesses and ocular lower-order aberrations and HOAs were found to be stable from 1 to 12 months, whereas total corneal, host stromal, and interface brightness intensities decreased significantly over the same period. A repeated measures analysis of variance performed across the follow-up period revealed that the change in scatter, but not the change in the HOAs, could account for the variability occurring in the acuity from 1 to 12 months post-DSAEK. CONCLUSIONS: Although ocular HOAs and scatter are both elevated over normal values post-DSAEK, our results demonstrate that the improvements in visual performance occurring over the first year post-DSAEK are associated with decreasing light scatter. In contrast, there were no significant changes in the ocular HOAs during this time. Because corneal light scatter decreased between 1 and 12 months despite there being stable corneal thicknesses over the same period, we conclude that factors that induced light scatter, other than tissue thickness or swelling (corneal edema), significantly impacted the visual improvements that occurred over time post-DSAEK. A better understanding of the cellular and extracellular matrix changes of the subepithelial region and interface, incurred by the surgical creation of a lamellar host-graft interface, and the subsequent healing of these tissues, is warranted.


Asunto(s)
Aberración de Frente de Onda Corneal/fisiopatología , Queratoplastia Endotelial de la Lámina Limitante Posterior , Seudofaquia/cirugía , Agudeza Visual/fisiología , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Topografía de la Córnea , Aberración de Frente de Onda Corneal/diagnóstico , Femenino , Deslumbramiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Seudofaquia/patología , Seudofaquia/fisiopatología , Tomografía de Coherencia Óptica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA