RESUMEN
Myelin is a vital structure that is key to rapid saltatory conduction in the central and peripheral nervous systems. Much work has been done over the decades examining the biochemical composition and morphology of myelin at the light and electron microscopic levels. Here we report a method to study myelin based on the fluorescent probe Nile Red. This lipophilic dye readily partitions into live and chemicallyfixed myelin producing bright, well-resolved images of the sheath. Using spectral confocal microscopy, a complete emission spectrum of Nile Red fluorescence can be acquired for each pixel in an image. The solvatochromic properties of Nile Red cause its emission spectrum to change depending on the polarity of its local environment. Therefore, measuring spectral shifts can report subtle changes in the physicochemical properties of myelin. We show differences in myelin polarity in central versus peripheral nervous system and in different regions of central nervous system white matter of the mouse brain, together with developmental and sex variations. This technique is also well suited for measuring subtle changes in myelin properties in live ex vivo white matter specimens. We also demonstrate how light deprivation induces a myelin polarity change in adult mouse optic nerve underscoring a continuing myelin plasticity in response to axonal activity well into adulthood. The Nile Red spectroscopic method allows measurement of subtle physicochemical changes in myelin that can importantly influence its electrical properties and by extension, conduction velocities in axons.
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COVID-19 , Defensa Civil , Control de Enfermedades Transmisibles , Emigrantes e Inmigrantes/estadística & datos numéricos , Vivienda Popular , Condiciones Sociales/legislación & jurisprudencia , Factores Socioeconómicos , COVID-19/epidemiología , COVID-19/prevención & control , Defensa Civil/métodos , Defensa Civil/organización & administración , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Control de Enfermedades Transmisibles/normas , Utilización de Instalaciones y Servicios/legislación & jurisprudencia , Utilización de Instalaciones y Servicios/normas , Predicción , Humanos , Salud Pública/métodos , Vivienda Popular/legislación & jurisprudencia , Vivienda Popular/organización & administración , Vivienda Popular/normas , SARS-CoV-2 , Singapur , Políticas de Control Social/tendencias , Marginación SocialRESUMEN
BACKGROUND: Classroom-based active breaks can help typically developing children reduce sitting, increase physical activity and improve cognitive functions and on-task behaviour. Yet, this strategy has not been tested in children with intellectual disability (ID) - a population who are insufficiently active. This study aimed to investigate the effects of a 5-week active breaks intervention on cognitive functions and on-task behaviour in schoolchildren with ID. METHODS: Twenty-four children, aged between 8 and 12 years (37.5% girls), were recruited. Children's cognitive functions (response inhibition, lapses of attention, interference and working memory) were measured at baseline and end of trial using computer-based tests. Sitting, standing and movement patterns were assessed with inclinometers, and on-task behaviour was directly observed in the classroom before and after active breaks, at baseline, mid-trial and end of trial. Linear mixed models were used to investigate the intervention effects on cognitive functions and sedentary patterns; generalised linear mixed models were used to analyse on-task behaviour data. RESULTS: A significant time × group interaction was found for working memory favouring the intervention (B = 11.56, 95% confidence interval [1.92, 21.21]). No significant effects were found in relation to the other measures of children's cognition or on-task behaviour. Stepping time and bouts of sitting were positively affected. CONCLUSIONS: Classroom-based active breaks can increase physical activity and reduce sedentary behaviour in children with ID and might also benefit their working memory. Further research is required to clarify the effects on cognition and to investigate whether this strategy has other benefits in this population.
Asunto(s)
Discapacidad Intelectual , Niño , Cognición , Femenino , Humanos , Masculino , Proyectos Piloto , Instituciones Académicas , Conducta SedentariaRESUMEN
BACKGROUND: Hearing aids (HA) is the primary medical intervention aimed to reduce hearing handicap. This study assessed the cost-effectiveness of HA for older adults who were volunteered to be screened for hearing loss in a community-based mobile hearing clinic (MHC). METHODS: Participants with (1) at least moderate hearing loss (≥40 dB HL) in at least one ear, (2) no prior usage of HA, (3) no ear related medical complications, and (4) had a Mini-Mental State Examination score ≥ 18 were eligible for this study. Using a delayed-start study design, participants were randomized into the immediate-start (Fitted) group where HA was fitted immediately or the delayed-start (Not Fitted) group where HA fitting was delayed for three months. Cost utility analysis was used to compare the cost-effectiveness of being fitted with HA combined with short-term, aural rehabilitation with the routine care group who were not fitted with HA. Incremental cost effectiveness ration (ICER) was computed. Health Utility Index (HUI-3) was used to measure utility gain, a component required to derive the quality adjusted life years (QALY). Total costs included direct healthcare costs, direct non-healthcare costs and indirect costs (productivity loss of participant and caregiver). Demographic data was collected during the index visit to MHC. Cost and utility data were collected three months after index visit and projected to five years. RESULTS: There were 264 participants in the Fitted group and 163 participants in the Not Fitted group. No between-group differences in age, gender, ethnicity, housing type and degree of hearing loss were observed at baseline. At 3 months, HA fitting led to a mean utility increase of 0.12 and an ICER gain of S$42,790/QALY (95% CI: S$32, 793/QALY to S$62,221/QALY). At five years, the ICER was estimated to be at S$11,964/QALY (95% CI: S$8996/QALY to S$17,080/QALY) assuming 70% of the participants continued using the HA. As fewer individuals continued using their fitted HA, the ICER increased. CONCLUSIONS: HA fitting can be cost-effective and could improve the quality of life of hearing-impaired older individuals within a brief period of device fitting. Long term cost-effectiveness of HA fitting is dependent on its continued usage.
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Costos de la Atención en Salud , Audífonos/economía , Anciano , Análisis Costo-Beneficio , Femenino , Pérdida Auditiva/rehabilitación , Pruebas Auditivas , Humanos , Masculino , Persona de Mediana Edad , Calidad de Vida , Años de Vida Ajustados por Calidad de VidaRESUMEN
OBJECTIVES: For a large part of the coronavirus disease 2019 (COVID-19) pandemic, Singapore had managed to keep local cases in the single digits daily, with decisive measures. Yet, we saw this critical time point when the imported cases surged through our borders. The gaps which we can and have efficiently closed, using a public health approach and global border containment strategies, are aptly illustrated through this case. This critical point of imported case surge has resulted in a large spike of daily local cases sustained through community transmission, up to 120/day within a very short time frame. We were able to rapidly bring this under control. STUDY DESIGN: This is a case study of a patient who passed through our borders, with COVID-19 masquerading as a resolved sore throat. METHODS: The events were prospectively documented. RESULTS: We present a case of a 21-year-old student returning from Nottingham. He presented with sore throat as the only symptom the few days prior his return, and on arrival at our border (day 7 from initial symptoms), his sore throat had already resolved. The events leading up to his COVID-19 diagnosis highlight the gaps of the international screening processes at the global border entry and the potential consequences of community chain transmission through imported COVID-19 cases. CONCLUSIONS: An important global border control measure to implement quickly will be to expand the symptom list to isolated sore throat and/or a prior history of recent symptoms (resolved). This may capture a larger proportion of imported cases at border entry point for more effective containment. This piece will be equally relevant to the general physicians, emergency care physicians, otolaryngologists and anaesthetists, who are at higher risk of encountering a throat visualization during intubation and routine examination. This information can be useful to countries with low resources or insufficient COVID-19 testing kits.
Asunto(s)
Enfermedades Transmisibles Importadas/prevención & control , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/prevención & control , Tamizaje Masivo/métodos , Pandemias/prevención & control , Faringitis/virología , Neumonía Viral/diagnóstico , Neumonía Viral/prevención & control , COVID-19 , Infecciones por Coronavirus/epidemiología , Humanos , Masculino , Neumonía Viral/epidemiología , Estudios Prospectivos , Singapur/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Age-related cognitive decline may be delayed with appropriate interventions if those at high risk can be identified prior to clinical symptoms arising. Gait variability assessment has emerged as a promising candidate prognostic indicator, however, it remains unclear how sensitive gait variability is to early changes in cognitive abilities. RESEARCH QUESTION: Do community-dwelling adults over 65 years of age with subjective memory complaints differ from those with no subjective memory concerns in terms of laboratory-measured or free-living gait variability? METHODS: This cross-sectional study recruited 24 (age = 73.5(SD 6.4) years) community-dwelling people with subjective memory complaints and twenty seven (age = 70.9(4.3) years) individuals with no subjective memory concerns. A sample of 9 individuals with diagnosed mild dementia were also assessed (age = 86.5(7.0) years). Gait variability was assessed in a laboratory during walking at preferred pace (single-task) and while counting backward by seven (dual-task). Sixteen passes over a 4.88 m walkway in each condition were recorded and step length and duration variability was analysed. Free-living gait was assessed with a waist-worn accelerometer by identifying gait bouts of at least one min duration, and the mean multiscale sample entropy in one mins non-overlapping epochs is reported. Statistical inferences were based on analysis of variance using sex and group as the factors. RESULTS: No difference between those with subjective memory complaints and those without were observed in either laboratory- or free-living gait variability estimates. Both laboratory- and free-living gait variability were higher in those with mild dementia compared to the other groups. SIGNIFICANCE: Assuming that subjective memory complaints are on the pathway from cognitively intact to cognitively frail, the findings raise the hypothesis that subjective memory complaints occur earlier in the pathophysiology than measurable changes in laboratory or free living gait. Alternatively the gait variability assessments utilised may have been too insensitive.
Asunto(s)
Disfunción Cognitiva/fisiopatología , Análisis de la Marcha , Marcha/fisiología , Acelerometría , Anciano , Anciano de 80 o más Años , Estudios Transversales , Demencia , Entropía , Femenino , Humanos , Vida Independiente , Masculino , MemoriaRESUMEN
Neuroblastoma, the most common solid tumor of young children, frequently presents with aggressive metastatic disease and for these children the 5-year survival rates are dismal. Metastasis, the movement of cancer cells from one site to another, involves remodeling of the cytoskeleton including altered microtubule dynamics. The microtubule-destabilizing protein, stathmin, has recently been shown to mediate neuroblastoma metastasis although precise functions remain poorly defined. In this study we investigated stathmin's contribution to the metastatic process and potential mechanism(s) by which it exerts these effects. Stathmin suppression significantly reduced neuroblastoma cell invasion of 3D tumor spheroids into an extracellular matrix. Moreover, inhibiting stathmin expression significantly reduced transendothelial migration in two different neuroblastoma cell lines in vitro. Inhibition of ROCK, a key regulator of cell migration, in neuroblastoma cells highlighted that stathmin regulates transendothelial migration through ROCK signaling. Reduced stathmin expression in neuroblastoma cells significantly increased the activation of the RhoA small GTPase. Notably, re-expression of either wild type or a phospho-mimetic stathmin mutant (4E) made defective in tubulin binding returned cell migration and transendothelial migration back to control levels, indicating that stathmin may influence these processes in neuroblastoma cells independent of tubulin binding. Finally, stathmin suppression in neuroblastoma cells significantly reduced whole body, lung, kidney and liver metastases in an experimental metastases mouse model. In conclusion, stathmin suppression interferes with the metastatic process via RhoA/ROCK signaling in neuroblastoma cells. These findings highlight the importance of stathmin to the metastatic process and its potential as a therapeutic target for the treatment of neuroblastoma.
Asunto(s)
Neuroblastoma/patología , Estatmina/antagonistas & inhibidores , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Animales , Línea Celular Tumoral , Xenoinjertos , Humanos , Masculino , Ratones , Ratones SCID , Metástasis de la Neoplasia , Neuroblastoma/metabolismo , Transducción de Señal , Estatmina/biosíntesis , Migración Transendotelial y Transepitelial , Transfección , Tubulina (Proteína)/metabolismoRESUMEN
In this paper, firstly, the morphology and toughness of a range of bulk epoxy polymers, which incorporate a second phase of well-dispersed silica nanoparticles and/or rubber microparticles, have been determined. Secondly, the macro-properties of natural-fibre reinforced-plastic (NFRP) composites based upon these epoxy polymers have been ascertained, using (i) unidirectional flax fibres or (ii) regenerated-cellulose fibres in the architecture of a plain-woven fabric. Thirdly, the toughening mechanisms which are induced in these materials by the presence of the silica nanoparticles, the rubber microparticles and the natural fibres have been identified. Finally, the values of the toughness of the bulk epoxy polymers and corresponding NFRPs have been quantitatively modelled. The increased toughness recorded for the bulk epoxy polymer due to the presence of the silica nanoparticles and/or rubber microparticles was indeed typically transferred to the NFRP composites when using such epoxies as the matrices for the fibres. Thus, the important role that may be played by modifications to the epoxy matrices in order to increase the toughness of the composites was very clearly demonstrated by these results. However, notwithstanding, the toughening mechanisms induced by the fibres were essentially responsible for the very high toughnesses of the NFRP composites, compared with the bulk epoxy polymers. The modelling studies successfully predicted the values of toughness of the bulk epoxy polymers and of the NFRP composites. These studies also quantified the extent to which each toughening mechanism, induced by the second-phase nano- and microparticles and the natural fibres, contributed to the overall values of toughness of the materials. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'.
Asunto(s)
Compuestos Epoxi/química , Ensayo de Materiales , Modelos Químicos , Nanocompuestos/química , Polímeros/química , Ingeniería , Goma , Dióxido de Silicio , TextilesRESUMEN
Loss of HOXA5 expression occurs frequently in breast cancer and correlates with higher pathological grade and poorer disease outcome. However, how HOX proteins drive differentiation in mammalian cells is poorly understood. In this paper, we investigated cellular and molecular consequences of loss of HOXA5 in breast cancer, and the role played by retinoic acid in HOXA5 function. Analysis of global gene expression data from HOXA5-depleted MCF10A breast epithelial cells, followed by validation, pointed to a role for HOXA5 in maintaining several molecular traits typical of the epithelial lineage such as cell-cell adhesion, tight junctions and markers of differentiation. Depleting HOXA5 in immortalized MCF10A or transformed MCF10A-Kras cells reduced their CD24+/CD44lo population, enhanced self-renewal capacity and reduced expression of E-cadherin (CDH1) and CD24. In the case of MCF10A-Kras, HOXA5 loss increased branching and protrusive morphology in Matrigel, all features suggestive of epithelial to basal transition. Further, orthotopically implanted xenografts of MCF10A-Kras-scr grew as well-differentiated pseudo-luminal carcinomas, while MCF10A-Kras-shHOXA5 cells formed aggressive, poorly differentiated carcinomas. Conversely, ectopic expression of HOXA5 in aggressive SUM149 or SUM159 breast cancer cells reversed the cellular and molecular alterations observed in the HOXA5-depleted cells. Retinoic acid is a known upstream regulator of HOXA5 expression. HOXA5 depletion in MCF10A cells engineered to express doxycycline-induced shHOXA5 slowed transition of cells from a less differentiated CD24-/CD44+ to the more differentiated CD24+/CD44+ state. This transition was promoted by retinal treatment, which upregulated endogenous HOXA5 expression and caused re-expression of occludin and claudin-7 (CLDN7). Expression of CDH1 and CD24 was transcriptionally upregulated by direct binding of HOXA5 to their promoter sequences as demonstrated by luciferase and ChIP analyses. Thus, loss of HOXA5 in mammary cells leads to loss of epithelial traits, an increase in stemness and cell plasticity, and the acquisition of more aggressive phenotypes.
Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Antígeno CD24/genética , Cadherinas/genética , Transformación Celular Neoplásica/genética , Regulación Neoplásica de la Expresión Génica , Proteínas de Homeodominio/genética , Animales , Antígenos CD , Cadherinas/metabolismo , Adhesión Celular , Línea Celular Tumoral , Autorrenovación de las Células/genética , Análisis por Conglomerados , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal/genética , Femenino , Perfilación de la Expresión Génica , Xenoinjertos , Proteínas de Homeodominio/metabolismo , Humanos , Ratones , Clasificación del Tumor , Regiones Promotoras Genéticas , Unión Proteica , Células Madre/metabolismoRESUMEN
AIM: A single session of skill or strength training can modulate the primary motor cortex (M1), which manifests as increased corticospinal excitability (CSE) and decreased short-latency intra-cortical inhibition (SICI). We tested the hypothesis that both skill and strength training can propagate the neural mechanisms mediating cross-transfer and modulate the ipsilateral M1 (iM1). METHODS: Transcranial magnetic stimulation (TMS) measured baseline CSE and SICI in the contralateral motor cortex (cM1) and iM1. Participants completed 4 sets of unilateral training with their dominant arm, either visuomotor tracking, metronome-paced strength training (MPST), self-paced strength training (SPST) or control. Immediately post training, TMS was repeated in both M1s. RESULTS: Motor-evoked potentials (MEPs) increased and inhibition was reduced for skill and MPST training from baseline in both M1s. Self-paced strength training and control did not produce changes in CSE and SICI when compared to baseline in both M1s. After training, skill and MPST increased CSE and decreased SICI in cM1 compared to SPST and control. Skill and MPST training decreased SICI in iM1 compared to SPST and control post intervention; however, CSE in iM1 was not different across groups post training. CONCLUSION: Both skill training and MPST facilitated an increase in CSE and released SICI in iM1 and cM1 compared to baseline. Our results suggest that synchronizing to an auditory or a visual cue promotes neural adaptations within the iM1, which is thought to mediate cross transfer.
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Potenciales Evocados Motores/fisiología , Aprendizaje/fisiología , Corteza Motora/fisiología , Destreza Motora/fisiología , Entrenamiento de Fuerza/métodos , Adulto , Estimulación Eléctrica , Electromiografía , Femenino , Humanos , Contracción Isométrica , Masculino , Rango del Movimiento Articular/fisiología , Estadísticas no Paramétricas , Estimulación Magnética Transcraneal , Adulto JovenRESUMEN
BACKGROUND: Due to limited end-of-life discussions and the absence of palliative care, hospitalisations are frequent at the end of life among nursing home residents in Singapore, resulting in high health-care costs. AIM: Our objective was to evaluate the economic impact of Project Care at the End-of-Life for Residents in homes for the Elderly (CARE) programme on nursing home residents compared to usual end-of-life care. DESIGN AND SETTINGS/PARTICIPANTS: Project CARE was introduced in seven nursing homes to provide advance care planning and palliative care for residents identified to be at risk of dying within 1 year. The cases consisted of nursing home residents enrolled in the Project CARE programme for at least 3 months. A historical group of nursing home residents not in any end-of-life care programme was chosen as the matched controls. Cost differences between the two groups were analysed over the last 3 months and final month of life. RESULTS: The final sample comprised 48 Project CARE cases and 197 controls. Compared to the controls, the cases were older with more comorbidities and higher nursing needs. After risk adjustment, Project CARE cases demonstrated per-resident cost savings of SGD$7129 (confidence interval: SGD$4544-SGD$9714) over the last 3 months of life and SGD$3703 (confidence interval: SGD$1848-SGD$5557) over the last month of life (US$1 = SGD$1.3). CONCLUSION: This study demonstrated substantial savings associated with an end-of-life programme. With a significant proportion of the population in Singapore requiring nursing home care in the near future, these results could assist policymakers and health-care providers in decision-making on allocation of health-care resources.
Asunto(s)
Costos de la Atención en Salud/estadística & datos numéricos , Hogares para Ancianos/economía , Casas de Salud/economía , Cuidado Terminal/economía , Anciano de 80 o más Años , Costos y Análisis de Costo , Femenino , Hospitalización/economía , Humanos , Masculino , Análisis de Regresión , Estudios Retrospectivos , SingapurRESUMEN
The microbial pattern-recognizing Toll-like receptors (TLRs) are major signal transducers known to shape and influence the postnatal maturation of host intestinal epithelium. Perturbations in this intricate host-microbe cross-talk have been reported to be associated with uncontrolled epithelial cell growth and thus potential cancer development by mechanisms which are largely unknown. We therefore generated transgenic mice carrying a constitutively active TLR4 (CD4-TLR4) linked to an intestinal epithelial cell-specific promoter. Ex vivo analysis of transgenic crypt-villus organoid cultures revealed an increased proliferative capacity and a lowered cyclooxygenase 2 (Cox-2) expression in these organoids compared with wild-type control cultures. Introducing the CD4-TLR4 transgene into APC(Min/+) mice (CD4-TLR4-APC(Min/+)), a model of colorectal carcinoma, resulted in a dramatic drop in tumor load as compared with control APC(Min/+) mice. Intestinal tumors from CD4-TLR4-APC(Min/+) mice displayed reduced Cox-2 protein, elevated interferon ß expression and increased caspase-3 activity, which correlated with increased apoptosis in vivo. Thus, our data reveal that host microbiota-mediated signal transduction via TLR4 in intestinal epithelial cells is far more complex than what is previously reported.
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Apoptosis , Mucosa Intestinal/metabolismo , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Animales , Caspasa 3/metabolismo , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Células Cultivadas , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Ciclooxigenasa 2/metabolismo , Femenino , Humanos , Immunoblotting , Inmunohistoquímica , Interferón beta/metabolismo , Mucosa Intestinal/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Organoides/citología , Organoides/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Receptor Toll-Like 4/genética , Carga Tumoral/genéticaRESUMEN
The HER2 (ERBB2) and MYC genes are commonly amplified in breast cancer, yet little is known about their molecular and clinical interaction. Using a novel chimeric mammary transgenic approach and in vitro models, we demonstrate markedly increased self-renewal and tumour-propagating capability of cells transformed with Her2 and c-Myc. Coexpression of both oncoproteins in cultured cells led to the activation of a c-Myc transcriptional signature and acquisition of a self-renewing phenotype independent of an epithelial-mesenchymal transition programme or regulation of conventional cancer stem cell markers. Instead, Her2 and c-Myc cooperated to induce the expression of lipoprotein lipase, which was required for proliferation and self-renewal in vitro. HER2 and MYC were frequently coamplified in breast cancer, associated with aggressive clinical behaviour and poor outcome. Lastly, we show that in HER2(+) breast cancer patients receiving adjuvant chemotherapy (but not targeted anti-Her2 therapy), MYC amplification is associated with a poor outcome. These findings demonstrate the importance of molecular and cellular context in oncogenic transformation and acquisition of a malignant stem-like phenotype and have diagnostic and therapeutic consequences for the clinical management of HER2(+) breast cancer.
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Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas Proto-Oncogénicas c-myc/fisiología , Receptor ErbB-2/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/mortalidad , Carcinoma Ductal de Mama/patología , Línea Celular Tumoral , Proliferación Celular , Femenino , Expresión Génica , Humanos , Ratones , Persona de Mediana Edad , Análisis Multivariante , Trasplante de Neoplasias , Fenotipo , Pronóstico , Análisis de Supervivencia , Transcriptoma , Adulto JovenRESUMEN
Repetitive finger tapping is a well-established clinical test for the evaluation of parkinsonian bradykinesia, but few studies have investigated other finger movement modalities. We compared the kinematic changes (movement rate and amplitude) and response to levodopa during a conventional index finger-thumb-tapping task and an unconstrained index finger flexion-extension task performed at maximal voluntary rate (MVR) for 20 s in 11 individuals with levodopa-responsive Parkinson's disease (OFF and ON) and 10 healthy age-matched controls. Between-task comparisons showed that for all conditions, the initial movement rate was greater for the unconstrained flexion-extension task than the tapping task. Movement rate in the OFF state was slower than in controls for both tasks and normalized in the ON state. The movement amplitude was also reduced for both tasks in OFF and increased in the ON state but did not reach control levels. The rate and amplitude of movement declined significantly for both tasks under all conditions (OFF/ON and controls). The time course of rate decline was comparable for both tasks and was similar in OFF/ON and controls, whereas the tapping task was associated with a greater decline in MA, both in controls and ON, but not OFF. The findings indicate that both finger movement tasks show similar kinematic changes during a 20-s sustained MVR, but that movement amplitude is less well sustained during the tapping task than the unconstrained finger movement task. Both movement rate and amplitude improved with levodopa; however, movement rate was more levodopa responsive than amplitude.
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Dedos/fisiopatología , Hipocinesia/fisiopatología , Movimiento/fisiología , Enfermedad de Parkinson/fisiopatología , Antiparkinsonianos/uso terapéutico , Fenómenos Biomecánicos/fisiología , Femenino , Humanos , Hipocinesia/complicaciones , Levodopa/uso terapéutico , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/tratamiento farmacológico , Desempeño Psicomotor/fisiologíaRESUMEN
Evidence that lipocalin 2 (LCN2) is oncogenic has grown in recent years and comes from both animal models and expression analysis from a variety of human cancers. In the intestine, LCN2 is overexpressed in colitis patients and its overexpression is a negative prognostic indicator in colorectal cancer. Functionally, LCN2 has a number of different activities that may contribute to its oncogenic potential, including increasing matrix metalloproteinase activity, control of iron availability and stimulating inflammation. In this report, we examined APCmin intestinal tumorigenesis in an LCN2-deficient background. We found that the loss of LCN2 increased tumor multiplicity specifically in the duodenum, suggesting a potential tumor-suppressive activity. Concurrently, however, LCN2 increased the average small intestinal tumor size particularly in the distal small intestine. We found that this increase was correlated to tumor iron(II) content, suggesting that an iron-scavenging role is important for LCN2 oncogenic activity in the intestine.
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Proteínas de Fase Aguda/biosíntesis , Neoplasias Intestinales/metabolismo , Neoplasias Intestinales/patología , Lipocalinas/biosíntesis , Proteínas Oncogénicas/biosíntesis , Proteínas de Fase Aguda/deficiencia , Proteínas de Fase Aguda/genética , Animales , Apoptosis/fisiología , Progresión de la Enfermedad , Femenino , Genes APC , Neoplasias Intestinales/genética , Lipocalina 2 , Lipocalinas/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Oncogénicas/deficiencia , Proteínas Oncogénicas/genéticaRESUMEN
This retrospective study was conducted among 59 HIV/AIDS patients with opportunistic infections admitted to the University Malaya Medical Centre between 2000 and 2009. Fifty-five point nine percent of cases were Chinese, 25.4% were Malays, 11.9% were Indians and 6.8% were of unknown ethnic origin. The male:female ratio was 2.9:1 (44 males and 15 females). The highest prevalence (38.9%) occurred in the 30-39 year old age group. Men comprised 47.7% and women 53.3%; the majority of both were married. The majority of cases were Malaysians (89.8%) and the rest (10.2%) were immigrants. Most of the patients (18.6%) were non-laborers, followed by laborers (11.9%), the unemployed (5.1%) and housewives (3.4%). The most common risk factor was unprotected sexual activity (20.3%). The two most common HIV/AIDS related opportunistic infections were Pneumocystis carinii (jirovecii) pneumonia (PCP) (62.7%) and toxoplasmosis (28.8%). Seventy-two point nine percent of patients had a CD4 count <200 cells/microl and 5.1% had a CD4 count >500 cells/microl. Eleven point nine percent of cases died during study period. A low CD4 count had a greater association with opportunistic infections. Most of the patients presented with fever (44.1%), cough (42.4%) and shortness of breath (28.8%). Detection of the etiologic pathogens aids clinicians in choosing appropriate management strategies.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Centros Médicos Académicos/estadística & datos numéricos , Infecciones por VIH/epidemiología , Neumonía por Pneumocystis/epidemiología , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Adulto , Distribución por Edad , Anciano , Recuento de Linfocito CD4 , Comorbilidad , Emigrantes e Inmigrantes/estadística & datos numéricos , Femenino , Conductas Relacionadas con la Salud , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Factores SocioeconómicosRESUMEN
The performance of a repetitive index finger flexion-extension task at maximal voluntary rate (MVR) begins to decline just a few seconds into the task and we have previously postulated that this breakdown has a central origin. To test this hypothesis, we have combined two objectives; to determine whether motor practice can lessen the performance deterioration in an MVR task, and whether further gains can be achieved with a transcranial magnetic stimulation (TMS) protocol that increases corticomotor excitability (CME). Eleven right-handed subjects participated in a randomized crossover study design that consisted of a 15-min interventional TMS at I-wave periodicity (ITMS) and single-pulsed Sham intervention prior to six 10-s practice sets of a repetitive finger flexion-extension task at MVR. Motor-evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle. The starting movement rate, and the percentage decline in rate by the end of the MVR were quantitated. Training of the MVR task improved the sustainability of the task by reducing the decline in movement rate. CME increased steadily after each training bout, and this increase was maintained up to 20 min after the last bout. ITMS further increased CME, and was associated with an increase in both the starting rate of the MVR task and its sustainability, when compared to Sham. The results implicate central motor processes in the performance and sustainability of the MVR task, and indicate that MVR kinematics can improve with short-term training and with non-invasive neuro-modulation.
Asunto(s)
Potenciales Evocados Motores/fisiología , Aprendizaje/fisiología , Corteza Motora/fisiología , Desempeño Psicomotor/fisiología , Adulto , Fenómenos Biomecánicos , Estudios Cruzados , Femenino , Dedos/fisiología , Humanos , Masculino , Tiempo de Reacción/fisiología , Estimulación Magnética Transcraneal , Adulto JovenRESUMEN
The Plasmodium falciparum serine repeat antigen (SERA) is one of the promising blood-stage malarial vaccine candidates. In this study, recombinant Mycobacterium bovis bacille Calmette-Guerin (rBCG) expressing the 22 kDa protein (SE22) from the 47 kDa Nterminal domain of serine repeat antigen (SERA), generated in favour of mycobacterium codon usage, elicited specific immune response in BALB/c mice with a mixed Th1/Th2 profile. Immunized sera containing high levels of specific IgG1 and IgG2a against the epitope (as determined by ELISA) were reactive with fixed P. falciparum merozoites as demonstrated by indirect immunofluorescence assay (IFA). Furthermore, the lymphocyte proliferative response to SE22 antigen from rBCG-immunized mice was higher than that of controls. The expression of intracellular cytokines (IL-2, IL-4 and IFNγ) in CD4+- and CD8+-cells was also enhanced following in-vitro stimulation with SE22. These findings indicate that a rBCG-based vaccine candidate expressing a blood-stage antigen of P. falciparum could enhance both humoral and cellular immune responses, thus paving the way for the rational use of rBCG as a vaccine candidate against malaria.
Asunto(s)
Antígenos de Protozoos/inmunología , Vacuna BCG/inmunología , Vacunas contra la Malaria/inmunología , Malaria Falciparum/prevención & control , Plasmodium falciparum/inmunología , Animales , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Formación de Anticuerpos , Antígenos de Protozoos/genética , Vacuna BCG/genética , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Clonación Molecular , Citocinas/inmunología , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta , Inmunidad Celular , Inmunidad Humoral , Inmunoglobulina G/sangre , Activación de Linfocitos , Linfocinas/inmunología , Vacunas contra la Malaria/genética , Malaria Falciparum/inmunología , Ratones , Ratones Endogámicos BALB C , Plasmodium falciparum/genética , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunologíaRESUMEN
Previous studies on handedness have often reported functional asymmetries in corticomotor excitability (CME) associated with voluntary movement. Recently, we have shown that the degree of post-exercise corticomotor depression (PED) and increase in short-interval cortical inhibition (SICI) after a repetitive finger movement task was less when the task was performed at a maximal voluntary rate (MVR) than when it was performed at a submaximal sustainable rate (SR). In the current study, we have compared the time course of PED and SICI in the dominant (DOM) and nondominant (NDOM) hands after an MVR and SR finger movement task to determine the influence of hand dominance and task demand. We tracked motor-evoked potential (MEP) amplitude from the first dorsal interosseous muscle of the DOM and NDOM hand for 20 min after a 10-s index finger flexion-extension task at MVR and SR. For all hand-task combinations, we report a period of PED and increased SICI lasting for up to 8 min. We find that the least demanding task, one that involved index finger movement of the DOM hand at SR, was associated with the greatest change in PED and SICI from baseline (63.6±5.7% and 79±2%, P<0.001, PED and SICI, respectively), whereas the most demanding task (MVR of the NDOM hand) was associated with the least change from baseline (PED: 88.1±3.6%, SICI: 103±2%; P<0.001). Our findings indicate that the changes in CME and inhibition associated with repetitive finger movement are influenced both by handedness and the degree of demand of the motor task and are inversely related to task demand, being smallest for an MVR task of the NDOM hand and greatest for an SR task of the DOM hand. The findings provide additional evidence for differences in neuronal processing between the dominant and nondominant hemispheres in motor control.