El sistema glimfático / The glymphatic system

Enero 22, 2018. No. 2971

El sistema glimfático: una guía para principiantes. El sistema glimfático es un sistema de eliminación de residuos macroscópico recientemente descubierto que utiliza un sistema único de túneles perivasculares, formado por células astrogliales, para promover la eliminación eficiente de proteínas solubles y metabolitos del sistema nervioso central. Además de la eliminación de desechos, el sistema glimfático también facilita la distribución de varios compuestos en el cerebro, incluyendo glucosa, lípidos, aminoácidos, factores de crecimiento y neuromoduladores. Curiosamente, el sistema glimfático funciona principalmente durante el sueño y se desconecta en gran medida durante la vigilia. La necesidad biológica de dormir en todas las especies puede por lo tanto reflejar que el cerebro debe entrar en un estado de actividad que permita la eliminación de productos de desecho potencialmente neurotóxicos, incluido el β-amiloide. Dado que el concepto del sistema glimfático es relativamente nuevo, revisaremos aquí sus elementos estructurales básicos, organización, regulación y funciones. También discutiremos los estudios recientes que indican que la función glimfatica se suprime en varias enfermedades y que la falla de la función glimfatica a su vez puede contribuir a la patología en trastornos neurodegenerativos, lesión cerebral traumática y apoplejía. The Glymphatic System: A Beginner's Guide. Jessen NA1, Munk AS2, Lundgaard I2, Nedergaard M2. Author information Neurochem Res. 2015 Dec;40(12):2583-99. doi: 10.1007/s11064-015-1581-6. Epub 2015 May 7. Abstract The glymphatic system is a recently discovered macroscopic waste clearance system that utilizes a unique system of perivascular tunnels, formed by astroglial cells, to promote efficient elimination of soluble proteins and metabolites from the central nervous system. Besides waste elimination, the glymphatic system also facilitates  brain-wide distribution of several compounds, including glucose, lipids, amino acids, growth factors, and neuromodulators. Intriguingly, the glymphatic system function mainly during sleep and is largely disengaged during wakefulness. The biological need for sleep across all species may therefore reflect that the brain must enter a state of activity that enables elimination of potentially neurotoxic waste products, including β-amyloid. Since the concept of the glymphatic system is relatively new, we will here review its basic structural elements, organization, regulation, and functions. We will also discuss recent studies indicating that glymphatic function is suppressed in various diseases and that failure of glymphatic function in turn might contribute to pathology in neurodegenerative disorders, traumatic brain injury and stroke. KEYWORDS: Aging; Astrocytes; Cerebrospinal fluid secretion; Neurodegenerative diseases; Perivascular spaces; Sleep; The glymphatic system; Traumatic brain injury; Virchow-Robin spaces PDF La anestesia general inhibe la actividad del sistema glimfático General Anesthesia Inhibits the Activity of the "Glymphatic System". Gakuba C1,2, Gaberel T1,3, Goursaud S1,2, Bourges J1,2, Di Palma C1,3, Quenault A1, de Lizarrondo SM1, Vivien D1,4, Gauberti M1,5. Author information Theranostics. 2018 Jan 1;8(3):710-722. doi: 10.7150/thno.19154. eCollection 2018. Abstract INTRODUCTION: According to the "glymphatic system" hypothesis, brain waste clearance is mediated by a continuous replacement of the interstitial milieu by a bulk flow of cerebrospinal fluid (CSF). Previous reports suggested that this cerebral CSF circulation is only active during general anesthesia or sleep, an effect mediated by the dilatation of the extracellular space. Given the controversies regarding the plausibility of this phenomenon and the limitations of currently available methods to image the glymphatic system, we developed original whole-brain in vivo imaging methods to investigate the effects of general anesthesia on the brain CSF circulation. METHODS: We used magnetic resonance imaging (MRI) and near-infrared fluorescence imaging (NIRF) after injection of a paramagnetic contrast agent or a fluorescent dye in the cisterna magna, in order to investigate the impact of general anesthesia (isoflurane, ketamine or ketamine/xylazine) on the intracranial CSF circulation in mice. RESULTS:In vivo imaging allowed us to image CSF flow in awake and anesthetized mice and confirmed the existence of a brain-wide CSF circulation. Contrary to what was initially thought, we demonstrated that the parenchymal CSF circulation is mainly active during wakefulness and significantly impaired during general anesthesia. This effect was especially significant when high doses of anesthetic agent were used (3% isoflurane). These results were consistent across the different anesthesia regimens and imaging modalities. Moreover, we failed to detect a significant change in the brain extracellular water volume using diffusion weighted imaging in awake and anesthetized mice. CONCLUSION: The parenchymal diffusion of small molecular weight compounds from the CSF is active during wakefulness. General anesthesia has a negative impact on the intracranial CSF circulation, especially when using a high dose of anesthetic agent. KEYWORDS: Alzheimer; anesthesia; choroid plexus.; glymphatic system; magnetic resonance imaging PDF La interferencia del sistema glimfático como mediador del trauma cerebral y la encefalopatía traumática crónica. Glymphatic system disruption as a mediator of brain trauma and chronic traumatic encephalopathy. Sullan MJ1, Asken BM2, Jaffee MS3, DeKosky ST4, Bauer RM5. Author information Neurosci Biobehav Rev. 2018 Jan;84:316-324. doi: 10.1016/j.neubiorev.2017.08.016. Epub 2017 Aug 30. Abstract Traumatic brain injury (TBI) is an increasingly important issue among veterans, athletes and the general public. Difficulties with sleep onset and maintenance are among the most commonly reported symptoms following injury, and sleep debt is associated with increased accumulation of beta amyloid (Aβ) and phosphorylated tau (p-tau) in the interstitial space. Recent research into the glymphatic system, a lymphatic-like metabolic clearance mechanism in the central nervous system (CNS) which relies on cerebrospinal fluid (CSF), interstitial fluid (ISF), and astrocytic processes, shows that clearance is potentiated during sleep. This system is damaged in the acute phase following mTBI, in part due to re-localization of aquaporin-4 channels away from astrocytic end feet, resulting in reduced potential for waste removal. Long-term consequences of chronic dysfunction within this system in the context of repetitive brain trauma and insomnia have not been established, but potentially provide one link in the explanatory chain connecting repetitive TBI with later neurodegeneration. Current research has shown p-tau deposition in perivascular spaces and along interstitial pathways in chronic traumatic encephalopathy (CTE), pathways related to glymphatic flow; these are the main channels by which metabolic waste is cleared. This review addresses possible links between mTBI-related damage to glymphatic functioning and physiological changes found in CTE, and proposes a model for the mediating role of sleep disruption in increasing the risk for developing CTE-related pathology and subsequent clinical symptoms following repetitive brain trauma. KEYWORDS: Aquaporin 4; Chronic traumatic encephalopathy; Glymphatic system; Insomnia; Sleep; Traumatic brain injury PDF Safe Anaesthesia Worldwide Delivering safe anaesthesia to the world's poorest people Informes / Information World Congress on Regional Anesthesia & Pain Medicine April 19-21, 2018, New York City, USA Informes / Information

Anestesiología y Medicina del Dolor 52 664 6848905 vwhizar@anestesia-dolor.org anestesia-dolor.org

Flexoelectricidad en huesos

http://www.artroscopiayreemplazos.com.mx/academia/flexoelectricidad-en-huesos/

Flexoelectricity in Bones.

Fuente

Este artículo es originalmente publicado en:

https://www.ncbi.nlm.nih.gov/pubmed/29345377

http://onlinelibrary.wiley.com/doi/10.1002/adma.201705316/abstract;jsessionid=F38FEA628757A858239DC2AF20E3ED8B.f02t01

De:

Vasquez-Sancho F1,2, Abdollahi A3, Damjanovic D4, Catalan G1,5.

Author information

1 Institut Català de Nanociencia i Nanotecnologia (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193, Barcelona, Catalonia, Spain.

2 Centro de Investigación en Ciencia e Ingeniería de Materiales (CICIMA), Universidad de Costa Rica, San José, 11501, Costa Rica.

3 Laboratori de Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya (UPC), Campus Nord UPC-C2, E-08034, Barcelona, Spain.

4 Ecole Politechnique Federale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland.

5 Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, E-08010, Barcelona, Catalonia, Spain.

Adv Mater. 2018 Jan 18. doi: 10.1002/adma.201705316. [Epub ahead of print]

Todos los derechos reservados para:

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Abstract

Bones generate electricity under pressure, and this electromechanical behavior is thought to be essential for bone’s self-repair and remodeling properties. The origin of this response is attributed to the piezoelectricity of collagen, which is the main structural protein of bones. In theory, however, any material can also generate voltages in response to strain gradients, thanks to the property known as flexoelectricity. In this work, the flexoelectricity of bone and pure bone mineral (hydroxyapatite) are measured and found to be of the same order of magnitude; the quantitative similarity suggests that hydroxyapatite flexoelectricity is the main source of bending-induced polarization in cortical bone. In addition, the measured flexoelectric coefficients are used to calculate the (flexo)electric fields generated by cracks in bone mineral. The results indicate that crack-generated flexoelectricity is theoretically large enough to induce osteocyte apoptosis and thus initiate the crack-healing process, suggesting a central role of flexoelectricity in bone repair and remodeling.

KEYWORDS:

bone remodeling; cracks; flexoelectricity; hydroxyapatite

Resumen

Los huesos generan electricidad bajo presión, y se considera que este comportamiento electromecánico es esencial para las propiedades de auto reparación y remodelación del hueso. El origen de esta respuesta se atribuye a la piezoelectricidad del colágeno, que es la principal proteína estructural de los huesos. En teoría, sin embargo, cualquier material también puede generar tensiones en respuesta a los gradientes de deformación, gracias a la propiedad conocida como flexoelectricidad. En este trabajo, se mide la flexoelectricidad del hueso y el mineral óseo puro (hidroxiapatita) y se encuentra que es del mismo orden de magnitud; la similitud cuantitativa sugiere que la flexoelectricidad de hidroxiapatita es la principal fuente de polarización inducida por flexión en el hueso cortical. Además, los coeficientes flexoeléctricos medidos se usan para calcular los campos eléctricos (flexo) generados por las grietas en el mineral óseo. Los resultados indican que la flexoelectricidad generada por grietas es teóricamente lo suficientemente grande como para inducir la apoptosis de osteocitos y, por lo tanto, iniciar el proceso de curación de grietas, lo que sugiere un papel central de la flexoelectricidad en la reparación y remodelación óseas.

PALABRAS CLAVE:

remodelación ósea; grietas; flexoelectricidad; hidroxiapatita

PMID:  29345377    DOI:   10.1002/adma.201705316

5°Maratón del hombro y codo doloroso. Mi hombro y codo ¡Basta de sentir dolor!

http://www.mihombroycodo.com.mx/academia/mi-hombro-y-codo-basta-de-sentir-dolor/

¡Basta de sentir dolor!

Este 27 y 28 de enero del 2018, tendrás a un grupo de expertos en Traumatología y Ortopedia, entre ellos a un servidor, totalmente dispuestos a ayudarte para sanar tu hombro o codo doloroso en el Hospital de Especialidades Catalina, ubicado en la calle Pablo Valdez 719, Col. San Juan de Dios.
¿En qué consiste el Maratón del Hombro y Codo Doloroso?
Se trata de un fin de semana completo en el que los especialistas te ayudarán a diagnosticar con exactitud la causa de tu dolor. El paquete de diagnóstico consiste en:
Una radiografía
Un ultrasonido
Consulta especializada con doctor ortopedista
¿Tiene costo?
El paquete completo estará al precio especial de $1,350.00 MXN
¿Cómo puedes obtenerlo?
Llama y haz tu cita con el Dr. Carlos Cortés al tel. +52 (33) 1204 0143 o directamente al Hospital de Especialidades Catalina al +52 (33) 3883 1080.
¡Apunta la fecha!
27 y 28 de enero del 2018

International Board of Shoulder and Elbow Surgeons, Dr Michell Ruiz, parte del comité científico del ICSES 2019 en Buenos Aires Argentina, representando a #México

http://www.lesionesdeportivas.com.mx/academia/international-board-of-shoulder-and-elbow-surgeons-dr-michell-ruiz-parte-del-comite-cientifico-del-icses-2019-en-buenos-aires-argentina-representando-a-mexico/

Dr. Michell Ruiz – Traumatólogo Alta especialidad en Hombro, Codo y Rodilla




️ REPRESENTANDO A MÉXICO

Agradecido con el International Board of Shoulder and Elbow Surgeons por seleccionarme para ser parte del comité científico del ICSES 2019 en Buenos Aires Argentina, representando a #México.

Este congreso es el más importante a nivel mundial y se realiza solo cada 3 años con los mejores cirujanos del mundo, líderes en Cirugía de Hombro y Codo.

Seguimos preparándonos para dar siempre lo mejor a nuestros pacientes.

Más información: https://www.icses2019.org/committees/

#Hombro #Codo #AltaEspecialización

5°Maratón del hombro y codo doloroso. Mi hombro y codo ¡Basta de sentir dolor!

http://www.mihombroycodo.com.mx/academia/mi-hombro-y-codo-basta-de-sentir-dolor/

¡Basta de sentir dolor!

Este 27 y 28 de enero del 2018, tendrás a un grupo de expertos en Traumatología y Ortopedia, entre ellos a un servidor, totalmente dispuestos a ayudarte para sanar tu hombro o codo doloroso en el Hospital de Especialidades Catalina, ubicado en la calle Pablo Valdez 719, Col. San Juan de Dios.

¿En qué consiste el Maratón del Hombro y Codo Doloroso?

Se trata de un fin de semana completo en el que los especialistas te ayudarán a diagnosticar con exactitud la causa de tu dolor. El paquete de diagnóstico consiste en:
Una radiografía
Un ultrasonido
Consulta especializada con doctor ortopedista
¿Tiene costo?

El paquete completo estará al precio especial de $1,350.00 MXN

¿Cómo puedes obtenerlo?

Llama y haz tu cita con el Dr. Carlos Cortés al tel. +52 (33) 1204 0143 o directamente al Hospital de Especialidades Catalina al +52 (33) 3883 1080.

¡Apunta la fecha!

27 y 28 de enero del 2018

Seguridad del paciente / Patient safety

Enero 18, 2018. No. 2966

Viñetas en seguridad del paciente. Volumen 1 Vignettes in Patient Safety - Volume 1 Edited by Michael S. Firstenberg and Stanislaw P. Stawicki, ISBN 978-953-51-3520-3, Print ISBN 978-953-51-3519-7, 186 pages, Publisher: InTech, Chapters published September 13, 2017 under CC BY 3.0 license DOI: 10.5772/66106 Edited Volume It is clearly recognized that medical errors represent a significant source of preventable healthcare-related morbidity and mortality. Furthermore, evidence shows that such complications are often the result of a series of smaller errors, missed opportunities, poor communication, breakdowns in established guidelines or protocols, or system-based deficiencies. While such events often start with the misadventures of an individual, it is how such events are managed that can determine outcomes and hopefully prevent future adverse events. The goal of Vignettes in Patient Safety is to illustrate and discuss, in a clinically relevant format, examples in which evidence-based approaches to patient care, using established methodologies to develop highly functional multidisciplinary teams, can help foster an institutional culture of patient safety and high-quality care delivery. Libro / Book / Livre Viñetas en seguridad del paciente. Volumen 2 Vignettes in Patient Safety - Volume 2 Edited by Michael S. Firstenberg and Stanislaw P. Stawicki, ISBN 978-953-51-3731-3, Print ISBN 978-953-51-3730-6, 200 pages, Publisher: InTech, Chapters published January 10, 2018 under CC BY 3.0 license DOI: 10.5772/intechopen.69032 Edited Volume Over the past two decades, the healthcare community increasingly recognized the importance and the impact of medical errors on patient safety and clinical outcomes. Medical and surgical errors continue to contribute to unnecessary and potentially preventable morbidity and/or mortality, affecting both ambulatory and hospital settings. The spectrum of contributing variables-ranging from minor errors that subsequently escalate to poor communication to lapses in appropriate protocols and processes (just to name a few)-is extensive, and solutions are only recently being described. As such, there is a growing body of research and experiences that can help provide an organized framework-based upon the best practices and evidence-based medical principles-for hospitals and clinics to foster patient safety culture and to develop institutional patient safety champions. Based upon the tremendous interest in the first volume of our Vignettes in Patient Safety series, this second volume follows a similar vignette-based model. Each chapter outlines a realistic case scenario designed to closely approximate experiences and clinical patterns that medical and surgical practitioners can easily relate to. Vignette presentations are then followed by an evidence-based overview of pertinent patient safety literature, relevant clinical evidence, and the formulation of preventive strategies and potential solutions that may be applicable to each corresponding scenario. Throughout the Vignettes in Patient Safety cycle, emphasis is placed on the identification and remediation of team-based and organizational factors associated with patient safety events. The second volume of the Vignettes in Patient Safety begins with an overview of recent high-impact studies in the area of patient safety. Subsequent chapters discuss a broad range of topics, including retained surgical items, wrong site procedures, disruptive healthcare workers, interhospital transfers, risks of emergency department overcrowding, dangers of inadequate handoff communication, and the association between provider fatigue and medical errors. By outlining some of the current best practices, structured experiences, and evidence-based recommendations, the authors and editors hope to provide our readers with new and significant insights into making healthcare safer for patients around the world. Libro / Book / Livre Safe Anaesthesia Worldwide Delivering safe anaesthesia to the world's poorest people Informes / Information World Congress on Regional Anesthesia & Pain Medicine April 19-21, 2018, New York City, USA Informes / Information

Anestesiología y Medicina del Dolor 52 664 6848905 vwhizar@anestesia-dolor.org anestesia-dolor.org

Un caso raro de hemimelia tibial, técnica quirúrgica y resultados clínicos

http://www.traumayortopedia.space/academia/un-caso-raro-de-hemimelia-tibial-tecnica-quirurgica-y-resultados-clinicos/

A rare case of tibial hemimelia, surgical technique and clinical results

Fuente

Este artículo es originalmente publicado en:

https://www.ncbi.nlm.nih.gov/pubmed/29248252

http://www.sciencedirect.com/science/article/pii/S1017995X17301359?via%3Dihub

De:

Basso M1, Camurri V2, Frediani P3, Boero S4.

Acta Orthop Traumatol Turc. 2017 Dec 13. pii: S1017-995X(17)30135-9. doi: 10.1016/j.aott.2017.11.004. [Epub ahead of print]

Todos los derechos reservados para:

Peer review under responsibility of Turkish Association of Orthopaedics and Traumatology.

© 2017 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V.

Abstract

We report a nine-year-old boy with a type IIIa tibial hemimelia, according to the new Paley classification. We describe the x-ray findings, the surgical treatment technique, and the prognostic course of the patient. Descriptions of such cases are very infrequent in the literature and type of treatment is still object of debate.

KEYWORDS:

Correction of pediatric deformity; Jones classification; Leg reconstruction; Paley classification; Tibial hemimelia; Weber classification

Resumen

Presentamos un niño de nueve años con una hemimelia tibial tipo IIIa, según la nueva clasificación de Paley. Describimos los hallazgos de rayos X, la técnica de tratamiento quirúrgico y el curso de pronóstico del paciente. Las descripciones de tales casos son muy infrecuentes en la literatura y el tipo de tratamiento sigue siendo objeto de debate.

PALABRAS CLAVE:

Corrección de la deformidad pediátrica; Clasificación de Jones; Reconstrucción de piernas; Clasificación de Paley; Hemimelia tibial; Clasificación Weber

PMID:  29248252  DOI:  10.1016/j.aott.2017.11.004

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