Fisiopatología de la hidrocefália idiopática de presión normal (parte 3): sistemaa glinfático

2016 ◽  
Vol 21 (2) ◽  
pp. 28-37
Author(s):  
Oscar Solís-Salgado ◽  
José Luis López-Payares ◽  
Mauricio Ayala-González
Keyword(s):  
Amyloid Beta ◽  
Interstitial Fluid ◽  
Amyloid Β ◽  
Bulk Flow ◽  
Polyethylene Glycols ◽  
Brain Interstitial Fluid ◽  
El Sistema ◽  
Arterial Pulsation ◽  
The Brain

Las vías de drenaje solutos del sistema nervioso central (SNC) participan en el recambio de liquido intersticial con el líquido cefalorraquídeo (LIT-LCR), generando un estado de homeostasis. Las alteraciones dentro de este sistema homeostático afectará la eliminación de solutos del espacio intersticial (EIT) como el péptido βa y proteína tau, los cuales son sustancias neurotóxicas para el SNC. Se han utilizado técnicas experimentales para poder analizar el intercambio LIT-LCR, las cuales revelan que este intercambio tiene una estructura bien organizada. La eliminación de solutos del SNC no tiene una estructura anatómica propiamente, se han descubierto vías de eliminación de solutos a través de marcadores florecentes en el espacio subaracnoideo, cisternas de la base y sistema ventricular que nos permiten observar una serie de vías ampliamente distribuidas en el cerebro. El LCR muestra que tiene una función linfática debido a su recambio con el LIT a lo largo de rutas paravasculares. Estos espacios que rodean la superficie arterial así como los espacios de Virchow-Robin y el pie astrocitico junto con la AQP-4, facilitan la entrada de LCR para-arterial y el aclaramiento de LIT para-venoso dentro del cerebro. El flujo y dirección que toma el LCR por estas estructuras, es conducido por la pulsación arterial. Esta función será la que finalmente llevara a la eliminación de estas sustancias neurotóxicas. En base a la dependencia de este flujo para la eliminación de sustancias se propone que el sistema sea llamado “ la Vía Glinfática”. La bibliografía así como las limitaciones que se encuentran en esta revisión están dadas por la metodología de búsqueda que ha sido realizada principalmente en PubMed utilizando los siguientes términos Mesh: Cerebral Arterial Pulsation, the brain via paravascular, drainage of amyloid-beta, bulk flow of brain interstitial fluid, radiolabeled polyethylene glycols and albumin, amyloid-β, the perivascular astroglial sheath, Brain Glymphatic Transport.

Secretory Bulk Flow of Soluble Proteins Is Efficient and COPII Dependent

2001 ◽  
Vol 13 (9) ◽  
pp. 2005-2020 ◽  
Author(s):  
B. A. Phillipson
Keyword(s):  
Soluble Proteins ◽  
Bulk Flow

Drainage of cerebral interstitial fluid into deep cervical lymph of the rabbit

1981 ◽  
Vol 240 (4) ◽  
pp. F329-F336 ◽  
Author(s):  
M. W. Bradbury ◽  
H. F. Cserr ◽  
R. J. Westrop
Keyword(s):  
Cerebrospinal Fluid ◽  
Caudate Nucleus ◽  
Subarachnoid Space ◽  
Interstitial Fluid ◽  
Bulk Flow ◽  
Perivascular Spaces ◽  
Csf Analysis ◽  
Intraventricular Injections ◽  
Intracerebral Microinjection ◽  
Do So

Lymph from the jugular lymph trunks of anesthetized rabbits has been continuously collected and radioiodinated albumin (RISA) therein estimated after microinjection of 1 microliter of 131I-albumin into the caudate nucleus, after single intraventricular injections, and during intraventricular infusions. Comparison of lymph at 7 and 25 h after intracerebral microinjection with efflux of radioactivity from whole brain suggests that about 50% of cleared radioactivity goes through lymph. Concentrations, normalized to cerebrospinal fluid (CSF), were much higher in lymph and retropharyngeal nodes after brain injection than after CSF injection or infusion. Also after brain injection, lymph and nodes contained more activity on injected side in contrast to lack of laterality after CSF administration. Calculation suggests that less than 30% of RISA cleared from brain can do so via a pool of well-mixed CSF. Analysis of tissues is compatible with much RISA draining by bulk flow via cerebral perivascular spaces plus passage from subarachnoid space of olfactory lobes into submucous spaces of nose and thus to lymph.

scholarly journals Label-free fingerprinting of tumor cells in bulk flow using inline digital holographic microscopy

2017 ◽  
Vol 8 (2) ◽  
pp. 536 ◽  
Author(s):  
Dhananjay Kumar Singh ◽  
Caroline C. Ahrens ◽  
Wei Li ◽  
Siva A. Vanapalli
Keyword(s):  
Tumor Cells ◽  
Bulk Flow ◽  
Digital Holographic Microscopy ◽  
Label Free ◽  
Holographic Microscopy

Studies of membrane phenomena. Part 5.—Bulk flow through membrane

1967 ◽  
Vol 63 (0) ◽  
pp. 2828-2838 ◽  
Author(s):  
Y. Toyoshima ◽  
Y. Kobatake ◽  
H. Fujita
Keyword(s):  
Bulk Flow ◽  
Flow Through

Hybrid Analysis of Gas Annular Seals With Energy Equation

2013 ◽  
Author(s):  
Patrick J. Migliorini ◽  
Alexandrina Untaroiu ◽  
William C. Witt ◽  
Neal R. Morgan ◽  
Houston G. Wood
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Energy Equation ◽  
Flow Analysis ◽  
Experimental Studies ◽  
Rotor System ◽  
Bulk Flow ◽  
Outlet Temperature ◽  
Cfd Analysis ◽  
Annular Seals

Annular seals are used in turbomachinery to reduce secondary flow between regions of high and low pressure. In a vibrating rotor system, the non-axisymmetric pressure field developed in the small clearance between the rotor and the seal generate reactionary forces that can affect the stability of the entire rotor system. Traditionally, two analyses have been used to study the fluid flow in seals, bulk-flow analysis and computational fluid dynamics (CFD). Bulk-flow methods are computational inexpensive, but solve simplified equations that rely on empirically derived coefficients and are moderately accurate. CFD analyses generally provide more accurate results than bulk-flow codes, but solution time can vary between days and weeks. For gas damper seals, these analyses have been developed with the assumption that the flow can be treated as isothermal. Some experimental studies show that the difference between the inlet and outlet temperature temperatures is less than 5% but initial CFD studies show that there can be a significant temperature change which can have an effect on the density field. Thus, a comprehensive analysis requires the solution of an energy equation. Recently, a new hybrid method that employs a CFD analysis for the base state, unperturbed flow and a bulk-flow analysis for the first order, perturbed flow has been developed. This method has shown to compare well with full CFD analysis and experimental data while being computationally efficient. In this study, the previously developed hybrid method is extended to include the effects of non-isothermal flow. The hybrid method with energy equation is then compared with the isothermal hybrid method and experimental data for several test cases of hole-pattern seals and the importance of the use of energy equation is studied.

Joint Estimation of Bulk Flow Velocity and Angle Using a Lateral Line Probe

2016 ◽  
Vol 65 (3) ◽  
pp. 601-613 ◽  
Author(s):  
Nataliya Strokina ◽  
Joni-Kristian Kamarainen ◽  
Jeffrey A. Tuhtan ◽  
Juan Francisco Fuentes-Perez ◽  
Maarja Kruusmaa
Keyword(s):  
Flow Velocity ◽  
Lateral Line ◽  
Joint Estimation ◽  
Bulk Flow
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