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Ameloblastoma is an odontogenic neoplasm characterized by slow intraosseous growth with progressive jaw resorption. Recent reports have revealed that ameloblastoma harbours an oncogenic BRAFV600E mutation with mitogen-activated protein kinase (MAPK) pathway activation and described cases of ameloblastoma harbouring a BRAFV600E mutation in which patients were successfully treated with a BRAF inhibitor. Therefore, the MAPK pathway may be involved in the development of ameloblastoma; however, the precise mechanism by which it induces ameloblastoma is unclear. The expression of ADP-ribosylation factor (ARF)-like 4c (ARL4C), induced by a combination of the EGF-MAPK pathway and Wnt/ß-catenin signalling, has been shown to induce epithelial morphogenesis. It was also reported that the overexpression of ARL4C, due to alterations in the EGF/RAS-MAPK pathway and Wnt/ß-catenin signalling, promotes tumourigenesis. However, the roles of ARL4C in ameloblastoma are unknown. We investigated the involvement of ARL4C in the development of ameloblastoma. In immunohistochemical analyses of tissue specimens obtained from 38 ameloblastoma patients, ARL4C was hardly detected in non-tumour regions but tumours frequently showed strong expression of ARL4C, along with the expression of both BRAFV600E and RAF1 (also known as C-RAF). Loss-of-function experiments using inhibitors or siRNAs revealed that ARL4C elevation depended on the RAF1-MEK/ERK pathway in ameloblastoma cells. It was also shown that the RAF1-ARL4C and BRAFV600E-MEK/ERK pathways promoted cell proliferation independently. ARL4C-depleted tumour cells (generated by knockdown or knockout) exhibited decreased proliferation and migration capabilities. Finally, when ameloblastoma cells were co-cultured with mouse bone marrow cells and primary osteoblasts, ameloblastoma cells induced osteoclast formation. ARL4C elevation in ameloblastoma further promoted its formation capabilities through the increased RANKL expression of mouse bone marrow cells and/or primary osteoblasts. These results suggest that the RAF1-MEK/ERK-ARL4C axis, which may function in cooperation with the BRAFV600E-MEK/ERK pathway, promotes ameloblastoma development. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Factores de Ribosilacion-ADP/metabolismo , Ameloblastoma/metabolismo , Proliferación Celular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Osteoclastos/patología , Ameloblastoma/genética , Proliferación Celular/fisiología , Transformación Celular Neoplásica/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Sistema de Señalización de MAP Quinasas/fisiología , Masculino , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Osteoclastos/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Vía de Señalización Wnt/genéticaRESUMEN
BACKGROUND: FACTS is a Wales-wide mental health service for 10-17-year-olds with needs beyond the remit of mainstream child and adolescent mental health services (CAMHS). As a purely consultation-liaison service, it differs from other UK services in the field. AIMS: To describe a complete cohort of referrals to FACTS 2013-2017 with service exit by June 2018. METHODS: Clinical, social and offending data were extracted from FACTS records. RESULTS: 80 young people completed a FACTS episode, averaging nearly a year (309 days; range 13-859 days). Mostly boys (65, 81%) of mean age 15.4 years (range 9-18), two-thirds (n = 53) had three or more referral reasons, one invariably being threatened/actual harm to others; only half were criminal-justice involved. Half (41, 51%) were committing sexually harmful acts. Half were self-harming (41, 51%). All but seven had had at least one adverse childhood experience (ACE), nearly half (35, 44%) four or more. Nevertheless, post-traumatic stress disorder (PTSD) was rarely diagnosed (7, 9%); just over one-quarter (23, 29%) had no diagnosis at all. Correspondence analyses endorsed two distinct Attention deficit hyperactivity disorder groups, distinguished by presence/absence of evidenced brain damage or dysfunction. Suicide-related behaviours clustered with the other diagnoses, flashbacks and psychotic symptoms with no diagnosis. Change in home circumstances during a FACTS episode was slight. CONCLUSIONS: The complexity of presenting problems and service involvement evidences need for FACTS. The extent of persistently harmful sexual behaviours is a novel finding, suggesting need for more expert input for this at other service levels. Rarity of PTSD diagnoses was surprising given the extent of ACEs. This raises concerns that services focus on disorder signs rather than the child's inner life. Given the extent of problems, minimal change may be a positive outcome - especially when remaining in the community. Further development of this service should include explicit case-by-case goals and indicative outcome markers.
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Trastorno por Déficit de Atención con Hiperactividad , Servicios de Salud Mental , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/terapia , Niño , Estudios de Cohortes , Derecho Penal , Femenino , Humanos , Masculino , Derivación y ConsultaRESUMEN
In 1978, the UK Library Association's newly formed Medical, Health and Welfare Libraries Group decided to establish a newsletter for its members. This paper sets out to describe how that newsletter evolved into Health Libraries Review (subsequently Health Information and Libraries Journal) and became the premier European journal for health-care information professionals. Drawing on both published accounts and personal reminiscences, it focuses on the role played by Shane Godbolt as the Review's founding editor. It analyses and discusses the factors that influenced her work, and concludes by summarising the lasting importance of her achievements as editor.
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Bibliotecas Médicas/historia , Publicaciones Periódicas como Asunto/historia , Historia del Siglo XX , Humanos , Bibliotecas Médicas/tendenciasRESUMEN
The immune system has evolved to sense invading pathogens, control infection, and restore tissue integrity. Despite symptomatic variability in patients, unequivocal evidence that an individual's immune system distinguishes between different organisms and mounts an appropriate response is lacking. We here used a systematic approach to characterize responses to microbiologically well-defined infection in a total of 83 peritoneal dialysis patients on the day of presentation with acute peritonitis. A broad range of cellular and soluble parameters was determined in peritoneal effluents, covering the majority of local immune cells, inflammatory and regulatory cytokines and chemokines as well as tissue damage-related factors. Our analyses, utilizing machine-learning algorithms, demonstrate that different groups of bacteria induce qualitatively distinct local immune fingerprints, with specific biomarker signatures associated with Gram-negative and Gram-positive organisms, and with culture-negative episodes of unclear etiology. Even more, within the Gram-positive group, unique immune biomarker combinations identified streptococcal and non-streptococcal species including coagulase-negative Staphylococcus spp. These findings have diagnostic and prognostic implications by informing patient management and treatment choice at the point of care. Thus, our data establish the power of non-linear mathematical models to analyze complex biomedical datasets and highlight key pathways involved in pathogen-specific immune responses.
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Bacterias/inmunología , Infecciones por Bacterias Gramnegativas/diagnóstico , Infecciones por Bacterias Grampositivas/diagnóstico , Aprendizaje Automático , Mapeo Peptídico/métodos , Diálisis Peritoneal/efectos adversos , Peritonitis/diagnóstico , Sistemas de Atención de Punto , Pruebas en el Punto de Atención , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Área Bajo la Curva , Bacterias/clasificación , Bacterias/patogenicidad , Biomarcadores/metabolismo , Estudios de Casos y Controles , Femenino , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/metabolismo , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Grampositivas/inmunología , Infecciones por Bacterias Grampositivas/metabolismo , Infecciones por Bacterias Grampositivas/microbiología , Interacciones Huésped-Patógeno , Humanos , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Reconocimiento de Normas Patrones Automatizadas , Peritonitis/inmunología , Peritonitis/metabolismo , Peritonitis/microbiología , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Factores de Tiempo , Adulto JovenRESUMEN
Wnt/ß-catenin and Wnt/Ca2+ pathways are involved in cellular processes during embryonic development and the interaction between them in the same cell decides the outcome of cellular functions. In this study, we showed that Wnt3a triggers the Wnt/Ca2+ signaling pathway, indicated by an increase of cytosolic free calcium ([Ca2+]i) and activation of calmodulin dependent kinase II (CaMKII) during the differentiation of human neuronal progenitor cells (hNPCs). Wnt3a via the increase of [Ca2+]i activates proline-rich tyrosine kinase 2 (Pyk2), which subsequently regulates phosphorylation of glycogen synthase kinase 3ß (GSK3ß) and ß-catenin stabilization. Our findings suggest that Pyk2 plays an important role in the coordination of stabilization of ß-catenin in the crosstalk between Wnt/ß-catenin and Wnt/Ca2+ signaling pathways upon Wnt3a stimulation in differentiating hNPCs.
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Quinasa 2 de Adhesión Focal/metabolismo , Células-Madre Neurales/fisiología , Neuronas/fisiología , Vía de Señalización Wnt/fisiología , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Diferenciación Celular/fisiología , Células Cultivadas , Regulación del Desarrollo de la Expresión Génica/fisiología , Humanos , Células-Madre Neurales/citología , Neuronas/citología , Receptor Cross-Talk/fisiologíaRESUMEN
Labial salivary gland (LSG) biopsy is used in the classification of primary Sjögren's syndrome (PSS) and in patient stratification in clinical trials. It may also function as a biomarker. The acquisition of tissue and histological interpretation is variable and needs to be standardised for use in clinical trials. A modified European League Against Rheumatism consensus guideline development strategy was used. The steering committee of the ad hoc working group identified key outstanding points of variability in LSG acquisition and analysis. A 2-day workshop was held to develop consensus where possible and identify points where further discussion/data was needed. These points were reviewed by a subgroup of experts on PSS histopathology and then circulated via an online survey to 50 stakeholder experts consisting of rheumatologists, histopathologists and oral medicine specialists, to assess level of agreement (0-10 scale) and comments. Criteria for agreement were a mean score ≥6/10 and 75% of respondents scoring ≥6/10. Thirty-nine (78%) experts responded and 16 points met criteria for agreement. These points are focused on tissue requirements, identification of the characteristic focal lymphocytic sialadenitis, calculation of the focus score, identification of germinal centres, assessment of the area of leucocyte infiltration, reporting standards and use of prestudy samples for clinical trials. We provide standardised consensus guidance for the use of labial salivary gland histopathology in the classification of PSS and in clinical trials and identify areas where further research is required to achieve evidence-based consensus.
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Centro Germinal/patología , Linfocitos/patología , Glándulas Salivales Menores/patología , Sialadenitis/patología , Síndrome de Sjögren/patología , Biopsia , Técnica Delphi , Humanos , Leucocitos/patología , Labio , Estándares de ReferenciaRESUMEN
Seasonal animals undergo changes in physiology and behavior between summer and winter conditions. These changes are in part driven by a switch in a series of hypothalamic genes under transcriptional control by hormones and, of recent interest, inflammatory factors. Crucial to the control of transcription are histone deacetylases (HDACs), generally acting to repress transcription by local histone modification. Seasonal changes in hypothalamic HDAC transcripts were investigated in photoperiod-sensitive F344 rats by altering the day-length (photoperiod). HDAC4, 6 and 9 were found to change in expression. The potential influence of HDACs on two hypothalamic signaling pathways that regulate transcription, inflammatory and nuclear receptor signaling, was investigated. For inflammatory signaling the focus was on NF-κB because of the novel finding made that its expression is seasonally regulated in the rat hypothalamus. For nuclear receptor signaling it was discovered that expression of retinoic acid receptor beta was regulated seasonally. HDAC modulation of NF-κB-induced pathways was examined in a hypothalamic neuronal cell line and primary hypothalamic tanycytes. HDAC4/5/6 inhibition altered the control of gene expression (Fos, Prkca, Prkcd and Ptp1b) by inducers of NF-κB that activate inflammation. These inhibitors also modified the action of nuclear receptor ligands thyroid hormone and retinoic acid. Thus seasonal changes in HDAC4 and 6 have the potential to epigenetically modify multiple gene regulatory pathways in the hypothalamus that could act to limit inflammatory pathways in the hypothalamus during long-day summer-like conditions.
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Histona Desacetilasas/genética , Hipotálamo/metabolismo , Fotoperiodo , Estaciones del Año , Transducción de Señal/fisiología , Animales , Línea Celular , Células Ependimogliales/efectos de los fármacos , Células Ependimogliales/metabolismo , Regulación de la Expresión Génica , Histona Desacetilasas/metabolismo , Hipotálamo/efectos de los fármacos , Inflamación/genética , Inflamación/metabolismo , Lipopolisacáridos/farmacología , FN-kappa B/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
OBJECTIVE: To examine the influence of real on-trade and off-trade alcohol prices and socioeconomic and environmental factors on rates of violence-related emergency department (ED) attendances in England and Wales over an 8-year period. METHODS: Anonymised injury data which included attendance date, age and gender of patients aged over 18â years who reported injury in violence were collected from a structured sample of 100 EDs across England and Wales between 1 January 2005 and 31 December 2012. Alcohol prices and socioeconomic measures were obtained from the UK Office for National Statistics. Panel techniques were used to derive a statistical model. RESULTS: Real on-trade (ß=-0.661, p<0.01) and off-trade (ß=-0.277, p<0.05) alcohol prices were negatively related with rates of violence-related ED attendance among the adult population of England and Wales, after accounting for the effects of regional poverty, income inequality, youth spending power and seasonal effects. It is estimated that over 6000 fewer violence-related ED attendances per year in England and Wales would result from a 1% increase in both on-trade and off-trade alcohol prices above inflation. Of the variables studied, changes in regional poverty and income inequality had the greatest effect on violence-related ED attendances in England and Wales. CONCLUSIONS: Small increases in the price of alcohol, above inflation, in both markets, would substantially reduce the number of patients attending EDs for treatment of violence-related injuries in England and Wales. Reforming the current alcohol taxation system may be more effective at reducing violence-related injury than minimum unit pricing.
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Consumo de Bebidas Alcohólicas/economía , Bebidas Alcohólicas/economía , Comercio/economía , Comercio/legislación & jurisprudencia , Violencia/prevención & control , Heridas y Lesiones/etiología , Heridas y Lesiones/prevención & control , Adulto , Distribución por Edad , Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/legislación & jurisprudencia , Servicio de Urgencia en Hospital/estadística & datos numéricos , Inglaterra/epidemiología , Femenino , Política de Salud , Investigación sobre Servicios de Salud , Humanos , Renta , Masculino , Formulación de Políticas , Vigilancia de la Población , Distribución por Sexo , Impuestos , Violencia/economía , Violencia/estadística & datos numéricos , Gales/epidemiología , Heridas y Lesiones/economía , Heridas y Lesiones/epidemiología , Adulto JovenRESUMEN
This study further develops the theoretical and empirical literature on the Behavioral Perspective Model (BPM) in three ways through an empirical analysis of the Great Britain (GB) biscuit category. First, following a literature review and a category analysis, a more complex model is constructed using the BPM structure and then testing the hypothesis uncovered. Second, the structure of the data theoretically calls for a hierarchical structure of the model, and hence, this is introduced into the BPM framework and is compared to a non-hierarchical structure of the same model. Finally, a discussion is undertaken on the advantages of a Bayesian approach to calculating parameter inference. Two models are built by utilizing vague and informed prior distributions respectively, and the results are compared. This study shows the importance of building appropriate model structures for analysis and demonstrates the advantages and challenges of utilizing a Bayesian approach. It also further demonstrates the BPM's suitability as a vehicle to better understand consumer behavior.
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This paper investigates the ability of connectionist models to explain consumer behavior, focusing on the feedforward neural network model, and explores the possibility of expanding the theoretical framework of the Behavioral Perspective Model to incorporate connectionist constructs. Numerous neural network models of varying complexity are developed to predict consumer loyalty as a crucial aspect of consumer behavior. Their performance is compared with the more traditional logistic regression model and it is found that neural networks offer consistent advantage over logistic regression in the prediction of consumer loyalty. Independently determined Utilitarian and Informational Reinforcement variables are shown to make a noticeable contribution to the explanation of consumer choice. The potential of connectionist models for predicting and explaining consumer behavior is discussed and routes for future research are suggested to investigate the predictive and explanatory capacity of connectionist models, such as neural network models, and for the integration of these into consumer behavior analysis within the theoretical framework of the Behavioral Perspective Model.
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Thyroid hormone (TH) is essential for adult brain function and its actions include several key roles in the hypothalamus. Although TH controls gene expression via specific TH receptors of the nuclear receptor class, surprisingly few genes have been demonstrated to be directly regulated by TH in the hypothalamus, or the adult brain as a whole. This study explored the rapid induction by TH of retinaldehyde dehydrogenase 1 (Raldh1), encoding a retinoic acid (RA)-synthesizing enzyme, as a gene specifically expressed in hypothalamic tanycytes, cells that mediate a number of actions of TH in the hypothalamus. The resulting increase in RA may then regulate gene expression via the RA receptors, also of the nuclear receptor class. In vivo exposure of the rat to TH led to a significant and rapid increase in hypothalamic Raldh1 within 4 hours. That this may lead to an in vivo increase in RA is suggested by the later induction by TH of the RA-responsive gene Cyp26b1. To explore the actions of RA in the hypothalamus as a potential mediator of TH control of gene regulation, an ex vivo hypothalamic rat slice culture method was developed in which the Raldh1-expressing tanycytes were maintained. These slice cultures confirmed that TH did not act on genes regulating energy balance but could induce Raldh1. RA has the potential to upregulate expression of genes involved in growth and appetite, Ghrh and Agrp. This regulation is acutely sensitive to epigenetic changes, as has been shown for TH action in vivo. These results indicate that sequential triggering of two nuclear receptor signalling systems has the capability to mediate some of the functions of TH in the hypothalamus.
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Células Ependimogliales/efectos de los fármacos , Hipotálamo/citología , Retinal-Deshidrogenasa/metabolismo , Hormonas Tiroideas/farmacología , Tretinoina/metabolismo , Proteína Relacionada con Agouti/genética , Proteína Relacionada con Agouti/metabolismo , Familia de Aldehído Deshidrogenasa 1 , Animales , Animales Recién Nacidos , Células Cultivadas , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas In Vitro , Masculino , Neuropéptido Y/genética , Neuropéptido Y/metabolismo , Técnicas de Cultivo de Órganos , Proopiomelanocortina/metabolismo , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley , Receptores de Ácido Retinoico/metabolismo , Retinal-Deshidrogenasa/genética , Especificidad de la Especie , Vimentina/metabolismoRESUMEN
INTRODUCTION: Substance use is a major risk factor for various forms of violence, yet how cigarette smoking influences violence outcomes is incompletely understood. We investigated associations between cigarette smoking and three types of violence in a large, nationally representative, community-based sample. METHODS: Adult subjects participating in both Wave 1 (2001-2002; N = 43 093) and Wave 2 (2004-2005; N = 34 653) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) were stratified by daily cigarette smoking status at Wave 1, and individuals with unchanged smoking status between waves were analyzed (nonsmokers [consisting of never and former daily smokers]: N = 22 529; daily smokers: N = 7442). We created composites of other- and self-directed violence and victimization occurring between Waves 1 and 2, and performed logistic regression models, controlling for psychiatric diagnoses, alcohol and substance use, and relevant demographic covariates. RESULTS: Daily smokers at Wave 1 were 2.1 (95% CI: 1.5-3.0), 2.5 (2.1-2.9), and 1.7 (1.5-2.1) times more likely than nonsmokers to report self-directed violence, other-directed violence, or victimization between Waves 1 and 2, respectively. Former daily smokers were significantly less likely to report other-directed violence than individuals who were never daily smokers. CONCLUSIONS: Daily cigarette smoking is temporally associated with multiple forms of violence compared to never and former cigarette smokers, even when common covariates associated with violence are controlled. Smoking status should be carefully controlled for in studies designed to identify risk factors for violence, and may be a useful component of violence risk assessment. IMPLICATIONS: The findings suggest that cigarette smoking status should be carefully and systematically controlled for in studies of violence risk factors. The findings also support further investigation of the utility of cigarette smoking status for violence risk assessment, and whether smoking cessation strategies mitigate violence risk.
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Fumar Cigarrillos/epidemiología , Violencia/estadística & datos numéricos , Adulto , Trastornos Relacionados con Alcohol/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Tabaquismo/epidemiologíaRESUMEN
We sought to develop a water, sanitation, and hygiene (WASH) intervention to minimize fecal-oral transmission among children aged 0-18 months in the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial. We undertook 4 phases of formative research, comprising in-depth interviews, focus group discussions, behavior trials, and a combination of observations and microbiological sampling methods. The resulting WASH intervention comprises material inputs and behavior change communication to promote stool disposal, handwashing with soap, water treatment, protected exploratory play, and hygienic infant feeding. Nurture and disgust were found to be key motivators, and are used as emotional triggers. The concept of a safe play space for young children was particularly novel, and families were eager to implement this after learning about the risks of unprotected exploratory play. An iterative process of formative research was essential to create a sequenced and integrated longitudinal intervention for a SHINE household as it expects (during pregnancy) and then cares for a new child.
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Heces/microbiología , Higiene , Intestinos/fisiopatología , Saneamiento , Ensayos Clínicos como Asunto/métodos , Ingestión de Alimentos , Femenino , Desinfección de las Manos , Conductas Relacionadas con la Salud , Hemoglobinas/análisis , Humanos , Lactante , Recién Nacido , Masculino , Proyectos de Investigación , Población Rural , Abastecimiento de Agua , ZimbabweRESUMEN
Ameloblastoma is a benign but locally infiltrative odontogenic neoplasm. Although ameloblastomas rarely metastasise, recurrences together with radical surgery often result in facial deformity and significant morbidity. Development of non-invasive therapies has been precluded by a lack of understanding of the molecular background of ameloblastoma pathogenesis. When addressing the role of ERBB receptors as potential new targets for ameloblastoma, we discovered significant EGFR over-expression in clinical samples using real-time RT-PCR, but observed variable sensitivity of novel primary ameloblastoma cells to EGFR-targeted drugs in vitro. In the quest for mutations downstream of EGFR that could explain this apparent discrepancy, Sanger sequencing revealed an oncogenic BRAF V600E mutation in the cell line resistant to EGFR inhibition. Further analysis of the clinical samples by Sanger sequencing and BRAF V600E-specific immunohistochemistry demonstrated a high frequency of BRAF V600E mutations (15 of 24 samples, 63%). These data provide novel insight into the poorly understood molecular pathogenesis of ameloblastoma and offer a rationale to test drugs targeting EGFR or mutant BRAF as novel therapies for ameloblastoma.
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Ameloblastoma/genética , Biomarcadores de Tumor/genética , Neoplasias Maxilomandibulares/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Ameloblastoma/tratamiento farmacológico , Ameloblastoma/enzimología , Ameloblastoma/patología , Antineoplásicos/farmacología , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Humanos , Neoplasias Maxilomandibulares/tratamiento farmacológico , Neoplasias Maxilomandibulares/enzimología , Neoplasias Maxilomandibulares/patología , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Selección de Paciente , Fenotipo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/metabolismo , Receptor ErbB-4 , Transducción de Señal/efectos de los fármacos , Adulto JovenRESUMEN
Glutamatergic neurotransmission mediated by N-methyl-d-aspartate (NMDA) receptors is vital for the cortical computations underlying cognition and might be disrupted in severe neuropsychiatric illnesses such as schizophrenia. Studies on this topic have been limited to processes in local circuits; however, cognition involves large-scale brain systems with multiple interacting regions. A prominent feature of the human brain's global architecture is the anticorrelation of default-mode vs. task-positive systems. Here, we show that administration of an NMDA glutamate receptor antagonist, ketamine, disrupted the reciprocal relationship between these systems in terms of task-dependent activation and connectivity during performance of delayed working memory. Furthermore, the degree of this disruption predicted task performance and transiently evoked symptoms characteristic of schizophrenia. We offer a parsimonious hypothesis for this disruption via biophysically realistic computational modeling, namely cortical disinhibition. Together, the present findings establish links between glutamate's role in the organization of large-scale anticorrelated neural systems, cognition, and symptoms associated with schizophrenia in humans.
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Encéfalo/fisiología , Cognición/fisiología , Receptores de N-Metil-D-Aspartato/fisiología , Esquizofrenia/fisiopatología , Adulto , Algoritmos , Encéfalo/efectos de los fármacos , Cognición/efectos de los fármacos , Método Doble Ciego , Antagonistas de Aminoácidos Excitadores/administración & dosificación , Antagonistas de Aminoácidos Excitadores/farmacología , Femenino , Humanos , Infusiones Intravenosas , Ketamina/administración & dosificación , Ketamina/farmacología , Imagen por Resonancia Magnética , Masculino , Memoria/efectos de los fármacos , Memoria/fisiología , Modelos Neurológicos , Reconocimiento Visual de Modelos/efectos de los fármacos , Reconocimiento Visual de Modelos/fisiología , Desempeño Psicomotor/efectos de los fármacos , Desempeño Psicomotor/fisiología , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Adulto JovenRESUMEN
BACKGROUND: Ketamine, the NMDA glutamate receptor antagonist drug, is increasingly employed as an experimental model of psychosis in healthy volunteers. At subanesthetic doses, it safely and reversibly causes delusion-like ideas, amotivation and perceptual disruptions reminiscent of the aberrant salience experiences that characterize first-episode psychosis. However, auditory verbal hallucinations, a hallmark symptom of schizophrenia, have not been reported consistently in healthy volunteers even at high doses of ketamine. SAMPLING AND METHODS: Here we present data from a set of healthy participants who received moderately dosed, placebo-controlled ketamine infusions in the reduced stimulation environment of the magnetic resonance imaging (MRI) scanner. We highlight the phenomenological experiences of 3 participants who experienced particularly vivid hallucinations. RESULTS: Participants in this series reported auditory verbal and musical hallucinations at a ketamine dose that does not induce auditory hallucination outside of the scanner. CONCLUSIONS: We interpret the observation of ketamine-induced auditory verbal hallucinations in the context of the reduced perceptual environment of the MRI scanner and offer an explanation grounded in predictive coding models of perception and psychosis - the brain fills in expected perceptual inputs, and it does so more in situations of altered perceptual input. The altered perceptual input of the MRI scanner creates a mismatch between top-down perceptual expectations and the heightened bottom-up signals induced by ketamine. Such circumstances induce aberrant percepts, including musical and auditory verbal hallucinations. We suggest that these circumstances might represent a useful experimental model of auditory verbal hallucinations and highlight the impact of ambient sensory stimuli on psychopathology.
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Lóbulo Frontal/efectos de los fármacos , Lóbulo Frontal/fisiopatología , Alucinaciones/inducido químicamente , Ketamina/efectos adversos , Trastornos Psicóticos/tratamiento farmacológico , Adulto , Deluciones/inducido químicamente , Relación Dosis-Respuesta a Droga , Femenino , Alucinaciones/diagnóstico , Humanos , Ketamina/administración & dosificación , Imagen por Resonancia Magnética , Masculino , Percepción , Trastornos Psicóticos/patología , Adulto JovenRESUMEN
The retinoids are a family of compounds that in nature are derived from vitamin A or pro-vitamin A carotenoids. An essential part of the diet for mammals, vitamin A has long been known to be essential for many organ systems in the adult. More recently, however, they have been shown to be necessary for function of the brain and new discoveries point to a central role in processes ranging from neuroplasticity to neurogenesis. Acting in several regions of the central nervous system including the eye, hippocampus and hypothalamus, one common factor in its action is control of biological rhythms. This review summarizes the role of vitamin A in the brain; its action through the metabolite retinoic acid via specific nuclear receptors, and the regulation of its concentration through controlled synthesis and catabolism. The action of retinoic acid to regulate several rhythms in the brain and body, from circadian to seasonal, is then discussed to finish with the importance of retinoic acid in the regular pattern of sleep. We review the role of vitamin A and retinoic acid (RA) as mediators of rhythm in the brain. In the suprachiasmatic nucleus and hippocampus they control expression of circadian clock genes while in the cortex retinoic acid is required for delta oscillations of sleep. Retinoic acid is also central to a second rhythm that keeps pace with the seasons, regulating function in the hypothalamus and pineal gland.
Asunto(s)
Encéfalo/fisiología , Ritmo Circadiano/fisiología , Plasticidad Neuronal/fisiología , Retinoides/metabolismo , Animales , HumanosRESUMEN
OBJECTIVE: As sex differences in substance dependence may impinge upon the perception and regulation of emotion, we assess emotional intelligence (EI) as a function of gender, menstrual cycle (MC) phase and hormonal changes in early abstinent cocaine-dependent individuals who abuse alcohol (CDA). METHODS: Study 1: The Mayer, Salovey, and Caruso Emotional Intelligence Test (MSCEIT) was administered to 98 CDA (55 M/43 F) and 56 healthy (28 M/28 F) individuals. Performance in women was also assessed by MC phase. Study 2: The MSCEIT was administered to 28 CDA (19 M/9 F) who received exogenous progesterone (400 mg/day) versus placebo for 7 days (study 2). RESULTS: Study 1: Healthy females were better than healthy males at facilitating thought and managing emotions. This gender discrepancy was not observed in the CDA group. Additionally, all women in the high compared with the low progesterone phase of their MC were better at managing their emotions. Study 2: Exogenous progesterone improved ability to facilitate thought in both males and females. CONCLUSIONS: CDA women may be vulnerable to difficulties managing and regulating emotions. Gonadal hormones may contribute to this gender effect, as increases in both endogenous and exogenous progesterone improved selective aspects of EI.