The Experts below are selected from a list of 4818 Experts worldwide ranked by ideXlab platform
Ingrid L Kwee - One of the best experts on this subject based on the ideXlab platform.
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fluid dynamics inside the brain barrier current concept of interstitial flow glymphatic flow and cerebrospinal fluid circulation in the brain
The Neuroscientist, 2019Co-Authors: Tsutomu Nakada, Ingrid L KweeAbstract:The discovery of the water specific channel, aquaporin, and abundant expression of its isoform, aquaporin-4 (AQP-4), on astrocyte endfeet brought about significant advancements in the understanding of brain fluid dynamics. The brain is protected by barriers preventing free access of systemic fluid. The same barrier system, however, also isolates brain interstitial fluid from the hydro-dynamic effect of the systemic circulation. The systolic force of the heart, an essential factor for proper systemic interstitial fluid circulation, cannot be propagated to the interstitial fluid compartment of the brain. Without a proper alternative mechanism, brain interstitial fluid would stay stagnant. Water influx into the peri-capillary Virchow-Robin Space (VRS) through the astrocyte AQP-4 system compensates for this hydrodynamic shortage essential for interstitial flow, introducing the condition virtually identical to systemic circulation, which by virtue of its fenestrated capillaries creates appropriate interstitial...
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fluid dynamics inside the brain barrier current concept of interstitial flow glymphatic flow and cerebrospinal fluid circulation in the brain
The Neuroscientist, 2019Co-Authors: Tsutomu Nakada, Ingrid L KweeAbstract:The discovery of the water specific channel, aquaporin, and abundant expression of its isoform, aquaporin-4 (AQP-4), on astrocyte endfeet brought about significant advancements in the understanding of brain fluid dynamics. The brain is protected by barriers preventing free access of systemic fluid. The same barrier system, however, also isolates brain interstitial fluid from the hydro-dynamic effect of the systemic circulation. The systolic force of the heart, an essential factor for proper systemic interstitial fluid circulation, cannot be propagated to the interstitial fluid compartment of the brain. Without a proper alternative mechanism, brain interstitial fluid would stay stagnant. Water influx into the peri-capillary Virchow-Robin Space (VRS) through the astrocyte AQP-4 system compensates for this hydrodynamic shortage essential for interstitial flow, introducing the condition virtually identical to systemic circulation, which by virtue of its fenestrated capillaries creates appropriate interstitial fluid motion. Interstitial flow in peri-arterial VRS constitutes an essential part of the clearance system for β-amyloid, whereas interstitial flow in peri-venous VRS creates bulk interstitial fluid flow, which, together with the choroid plexus, creates the necessary ventricular cerebrospinal fluid (CSF) volume for proper CSF circulation.
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Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood-brain barrier: [17O]H2O JJVCPE MRI study.
NeuroReport, 2018Co-Authors: Vincent J. Huber, Hironaka Igarashi, Ingrid L Kwee, Satoshi Ueki, Tsutomu NakadaAbstract:The blood-brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow-Robin Space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow-Robin Space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial Space promoting circulation of interstitial fluid within the BBB.
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aquaporin 4 functionality and virchow robin Space water dynamics physiological model for neurovascular coupling and glymphatic flow
International Journal of Molecular Sciences, 2017Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Ingrid L Kwee, Yuji SuzukiAbstract:The unique properties of brain capillary endothelium, critical in maintaining the blood-brain barrier (BBB) and restricting water permeability across the BBB, have important consequences on fluid hydrodynamics inside the BBB hereto inadequately recognized. Recent studies indicate that the mechanisms underlying brain water dynamics are distinct from systemic tissue water dynamics. Hydrostatic pressure created by the systolic force of the heart, essential for interstitial circulation and lymphatic flow in systemic circulation, is effectively impeded from propagating into the interstitial fluid inside the BBB by the tightly sealed endothelium of brain capillaries. Instead, fluid dynamics inside the BBB is realized by aquaporin-4 (AQP-4), the water channel that connects astrocyte cytoplasm and extracellular (interstitial) fluid. Brain interstitial fluid dynamics, and therefore AQP-4, are now recognized as essential for two unique functions, namely, neurovascular coupling and glymphatic flow, the brain equivalent of systemic lymphatics.
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water influx into cerebrospinal fluid is significantly reduced in senile plaque bearing transgenic mice supporting beta amyloid clearance hypothesis of alzheimer s disease
Neurological Research, 2014Co-Authors: Hironaka Igarashi, Yuji Suzuki, Ingrid L Kwee, Tsutomu NakadaAbstract:Recent studies on cerebrospinal fluid (CSF) homeostasis emphasize the importance of water influx into the peri-capillary (Virchow–Robin) Space through aquaporin 4 (AQP-4). This water flow is believed to have the functionality equivalent to the systemic lymphatic system and plays a critical role in beta-amyloid clearance. Using a newly developed molecular imaging technique capable of tracing water molecules, in vivo, water influx into the CSF was quantitatively analyzed in senile plaque (SP) bearing transgenic Alzheimer’s disease (AD) model mice. The results unequivocally demonstrated that water influx into CSF is significantly impaired in SP-bearing transgenic mice, the degree of which being virtually identical to that previously observed in AQP-4 knockout mice. The study strongly indicates that disturbance in AQP-4-based water flow and, hence, impairment in beta-amyloid clearance play a significant role in SP formation.
Tsutomu Nakada - One of the best experts on this subject based on the ideXlab platform.
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fluid dynamics inside the brain barrier current concept of interstitial flow glymphatic flow and cerebrospinal fluid circulation in the brain
The Neuroscientist, 2019Co-Authors: Tsutomu Nakada, Ingrid L KweeAbstract:The discovery of the water specific channel, aquaporin, and abundant expression of its isoform, aquaporin-4 (AQP-4), on astrocyte endfeet brought about significant advancements in the understanding of brain fluid dynamics. The brain is protected by barriers preventing free access of systemic fluid. The same barrier system, however, also isolates brain interstitial fluid from the hydro-dynamic effect of the systemic circulation. The systolic force of the heart, an essential factor for proper systemic interstitial fluid circulation, cannot be propagated to the interstitial fluid compartment of the brain. Without a proper alternative mechanism, brain interstitial fluid would stay stagnant. Water influx into the peri-capillary Virchow-Robin Space (VRS) through the astrocyte AQP-4 system compensates for this hydrodynamic shortage essential for interstitial flow, introducing the condition virtually identical to systemic circulation, which by virtue of its fenestrated capillaries creates appropriate interstitial...
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fluid dynamics inside the brain barrier current concept of interstitial flow glymphatic flow and cerebrospinal fluid circulation in the brain
The Neuroscientist, 2019Co-Authors: Tsutomu Nakada, Ingrid L KweeAbstract:The discovery of the water specific channel, aquaporin, and abundant expression of its isoform, aquaporin-4 (AQP-4), on astrocyte endfeet brought about significant advancements in the understanding of brain fluid dynamics. The brain is protected by barriers preventing free access of systemic fluid. The same barrier system, however, also isolates brain interstitial fluid from the hydro-dynamic effect of the systemic circulation. The systolic force of the heart, an essential factor for proper systemic interstitial fluid circulation, cannot be propagated to the interstitial fluid compartment of the brain. Without a proper alternative mechanism, brain interstitial fluid would stay stagnant. Water influx into the peri-capillary Virchow-Robin Space (VRS) through the astrocyte AQP-4 system compensates for this hydrodynamic shortage essential for interstitial flow, introducing the condition virtually identical to systemic circulation, which by virtue of its fenestrated capillaries creates appropriate interstitial fluid motion. Interstitial flow in peri-arterial VRS constitutes an essential part of the clearance system for β-amyloid, whereas interstitial flow in peri-venous VRS creates bulk interstitial fluid flow, which, together with the choroid plexus, creates the necessary ventricular cerebrospinal fluid (CSF) volume for proper CSF circulation.
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Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood-brain barrier: [17O]H2O JJVCPE MRI study.
NeuroReport, 2018Co-Authors: Vincent J. Huber, Hironaka Igarashi, Ingrid L Kwee, Satoshi Ueki, Tsutomu NakadaAbstract:The blood-brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow-Robin Space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow-Robin Space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial Space promoting circulation of interstitial fluid within the BBB.
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aquaporin 4 functionality and virchow robin Space water dynamics physiological model for neurovascular coupling and glymphatic flow
International Journal of Molecular Sciences, 2017Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Ingrid L Kwee, Yuji SuzukiAbstract:The unique properties of brain capillary endothelium, critical in maintaining the blood-brain barrier (BBB) and restricting water permeability across the BBB, have important consequences on fluid hydrodynamics inside the BBB hereto inadequately recognized. Recent studies indicate that the mechanisms underlying brain water dynamics are distinct from systemic tissue water dynamics. Hydrostatic pressure created by the systolic force of the heart, essential for interstitial circulation and lymphatic flow in systemic circulation, is effectively impeded from propagating into the interstitial fluid inside the BBB by the tightly sealed endothelium of brain capillaries. Instead, fluid dynamics inside the BBB is realized by aquaporin-4 (AQP-4), the water channel that connects astrocyte cytoplasm and extracellular (interstitial) fluid. Brain interstitial fluid dynamics, and therefore AQP-4, are now recognized as essential for two unique functions, namely, neurovascular coupling and glymphatic flow, the brain equivalent of systemic lymphatics.
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water influx into cerebrospinal fluid is significantly reduced in senile plaque bearing transgenic mice supporting beta amyloid clearance hypothesis of alzheimer s disease
Neurological Research, 2014Co-Authors: Hironaka Igarashi, Yuji Suzuki, Ingrid L Kwee, Tsutomu NakadaAbstract:Recent studies on cerebrospinal fluid (CSF) homeostasis emphasize the importance of water influx into the peri-capillary (Virchow–Robin) Space through aquaporin 4 (AQP-4). This water flow is believed to have the functionality equivalent to the systemic lymphatic system and plays a critical role in beta-amyloid clearance. Using a newly developed molecular imaging technique capable of tracing water molecules, in vivo, water influx into the CSF was quantitatively analyzed in senile plaque (SP) bearing transgenic Alzheimer’s disease (AD) model mice. The results unequivocally demonstrated that water influx into CSF is significantly impaired in SP-bearing transgenic mice, the degree of which being virtually identical to that previously observed in AQP-4 knockout mice. The study strongly indicates that disturbance in AQP-4-based water flow and, hence, impairment in beta-amyloid clearance play a significant role in SP formation.
Yuji Suzuki - One of the best experts on this subject based on the ideXlab platform.
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aquaporin 4 functionality and virchow robin Space water dynamics physiological model for neurovascular coupling and glymphatic flow
International Journal of Molecular Sciences, 2017Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Ingrid L Kwee, Yuji SuzukiAbstract:The unique properties of brain capillary endothelium, critical in maintaining the blood-brain barrier (BBB) and restricting water permeability across the BBB, have important consequences on fluid hydrodynamics inside the BBB hereto inadequately recognized. Recent studies indicate that the mechanisms underlying brain water dynamics are distinct from systemic tissue water dynamics. Hydrostatic pressure created by the systolic force of the heart, essential for interstitial circulation and lymphatic flow in systemic circulation, is effectively impeded from propagating into the interstitial fluid inside the BBB by the tightly sealed endothelium of brain capillaries. Instead, fluid dynamics inside the BBB is realized by aquaporin-4 (AQP-4), the water channel that connects astrocyte cytoplasm and extracellular (interstitial) fluid. Brain interstitial fluid dynamics, and therefore AQP-4, are now recognized as essential for two unique functions, namely, neurovascular coupling and glymphatic flow, the brain equivalent of systemic lymphatics.
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water influx into cerebrospinal fluid is significantly reduced in senile plaque bearing transgenic mice supporting beta amyloid clearance hypothesis of alzheimer s disease
Neurological Research, 2014Co-Authors: Hironaka Igarashi, Yuji Suzuki, Ingrid L Kwee, Tsutomu NakadaAbstract:Recent studies on cerebrospinal fluid (CSF) homeostasis emphasize the importance of water influx into the peri-capillary (Virchow–Robin) Space through aquaporin 4 (AQP-4). This water flow is believed to have the functionality equivalent to the systemic lymphatic system and plays a critical role in beta-amyloid clearance. Using a newly developed molecular imaging technique capable of tracing water molecules, in vivo, water influx into the CSF was quantitatively analyzed in senile plaque (SP) bearing transgenic Alzheimer’s disease (AD) model mice. The results unequivocally demonstrated that water influx into CSF is significantly impaired in SP-bearing transgenic mice, the degree of which being virtually identical to that previously observed in AQP-4 knockout mice. The study strongly indicates that disturbance in AQP-4-based water flow and, hence, impairment in beta-amyloid clearance play a significant role in SP formation.
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alzheimer patients show significant disturbance in water influx into csf Space strongly supporting β amyloid clearance hypothesis s58 001
Neurology, 2014Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Yuji Suzuki, Ingrid L KweeAbstract:OBJECTIVE: To investigate whether or not water influx into cerebrospinal fluid (CSF) Space is disturbed in Alzheimer patients as has been shown in transgenic Alzheimer model mice. BACKGROUND: Recent studies on CSF homeostasis emphasize the importance of water flux through the peri-capillary (Virchow-Robin) Space for both CSF production and reabsorption (Oreskovic and Klarica hypothesis). CSF influx through aquaporin-4 (AQP-4) is likely to play a role as the brain’s equivalent of lymphatic drainage and believed to be critical for proper β-amyloid clearance. Utilizing an amyloid precursor protein (APP) overproduction Alzheimer disease model mice and [17O]H 2 O JJ vicinal coupling proton exchange (JJVCPE) MRI imaging, we discovered that APP overproduction alone is not sufficient to form senile plaque. An additional condition is necessary: a significant reduction of water influx into the CSF Space, presumably representing significant disturbance in β-amyloid clearance. DESIGN/METHODS: Six young volunteers (21-24 y/o), seven senior volunteers (60-78 y/o, MMSE 蠅 26), and six Alzheimer’s disease (AD) patients (59-84 y/o, MMSE: 13-19) were included in this study. All AD patients were diagnosed based on DSM-IV criteria. CSF dynamics were analyzed using positron emission tomography (PET) following an intravenous injection of 1,000 MBq [15O]H2O synthesized on-line. RESULTS: Water influx into CSF in AD patients expressed as influx ratio (0.761±0.009) is significantly reduced (p < 0.001) compared to young controls (1.329 ±0.218). Senior controls showed a large range of influx ratio (0.599-1.442) suggesting that reduction in water influx into CSF represents one of the “aging” processes. CONCLUSIONS: Reduction in water influx into the CSF and clearance rate of β-amyloid is the necessary, if not sufficient, factor in pathogenesis of AD. Cohort studies for assessing dynamical indices of the balance between production and clearance of β-amyloid among various populations, including mild cognitive impairment (MCI) patients appears to be critical for our proper understanding of the pathogenesis of AD. Study Supported by: Ministry of Education, Culture, Sports, Science, and Technology (Japan) Disclosure: Dr. Nakada has nothing to disclose. Dr. Igarashi has nothing to disclose. Dr. Suzuki has nothing to disclose. Dr. Kwee has nothing to disclose.
Hironaka Igarashi - One of the best experts on this subject based on the ideXlab platform.
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Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood-brain barrier: [17O]H2O JJVCPE MRI study.
NeuroReport, 2018Co-Authors: Vincent J. Huber, Hironaka Igarashi, Ingrid L Kwee, Satoshi Ueki, Tsutomu NakadaAbstract:The blood-brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow-Robin Space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow-Robin Space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial Space promoting circulation of interstitial fluid within the BBB.
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aquaporin 4 functionality and virchow robin Space water dynamics physiological model for neurovascular coupling and glymphatic flow
International Journal of Molecular Sciences, 2017Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Ingrid L Kwee, Yuji SuzukiAbstract:The unique properties of brain capillary endothelium, critical in maintaining the blood-brain barrier (BBB) and restricting water permeability across the BBB, have important consequences on fluid hydrodynamics inside the BBB hereto inadequately recognized. Recent studies indicate that the mechanisms underlying brain water dynamics are distinct from systemic tissue water dynamics. Hydrostatic pressure created by the systolic force of the heart, essential for interstitial circulation and lymphatic flow in systemic circulation, is effectively impeded from propagating into the interstitial fluid inside the BBB by the tightly sealed endothelium of brain capillaries. Instead, fluid dynamics inside the BBB is realized by aquaporin-4 (AQP-4), the water channel that connects astrocyte cytoplasm and extracellular (interstitial) fluid. Brain interstitial fluid dynamics, and therefore AQP-4, are now recognized as essential for two unique functions, namely, neurovascular coupling and glymphatic flow, the brain equivalent of systemic lymphatics.
-
water influx into cerebrospinal fluid is significantly reduced in senile plaque bearing transgenic mice supporting beta amyloid clearance hypothesis of alzheimer s disease
Neurological Research, 2014Co-Authors: Hironaka Igarashi, Yuji Suzuki, Ingrid L Kwee, Tsutomu NakadaAbstract:Recent studies on cerebrospinal fluid (CSF) homeostasis emphasize the importance of water influx into the peri-capillary (Virchow–Robin) Space through aquaporin 4 (AQP-4). This water flow is believed to have the functionality equivalent to the systemic lymphatic system and plays a critical role in beta-amyloid clearance. Using a newly developed molecular imaging technique capable of tracing water molecules, in vivo, water influx into the CSF was quantitatively analyzed in senile plaque (SP) bearing transgenic Alzheimer’s disease (AD) model mice. The results unequivocally demonstrated that water influx into CSF is significantly impaired in SP-bearing transgenic mice, the degree of which being virtually identical to that previously observed in AQP-4 knockout mice. The study strongly indicates that disturbance in AQP-4-based water flow and, hence, impairment in beta-amyloid clearance play a significant role in SP formation.
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alzheimer patients show significant disturbance in water influx into csf Space strongly supporting β amyloid clearance hypothesis s58 001
Neurology, 2014Co-Authors: Tsutomu Nakada, Hironaka Igarashi, Yuji Suzuki, Ingrid L KweeAbstract:OBJECTIVE: To investigate whether or not water influx into cerebrospinal fluid (CSF) Space is disturbed in Alzheimer patients as has been shown in transgenic Alzheimer model mice. BACKGROUND: Recent studies on CSF homeostasis emphasize the importance of water flux through the peri-capillary (Virchow-Robin) Space for both CSF production and reabsorption (Oreskovic and Klarica hypothesis). CSF influx through aquaporin-4 (AQP-4) is likely to play a role as the brain’s equivalent of lymphatic drainage and believed to be critical for proper β-amyloid clearance. Utilizing an amyloid precursor protein (APP) overproduction Alzheimer disease model mice and [17O]H 2 O JJ vicinal coupling proton exchange (JJVCPE) MRI imaging, we discovered that APP overproduction alone is not sufficient to form senile plaque. An additional condition is necessary: a significant reduction of water influx into the CSF Space, presumably representing significant disturbance in β-amyloid clearance. DESIGN/METHODS: Six young volunteers (21-24 y/o), seven senior volunteers (60-78 y/o, MMSE 蠅 26), and six Alzheimer’s disease (AD) patients (59-84 y/o, MMSE: 13-19) were included in this study. All AD patients were diagnosed based on DSM-IV criteria. CSF dynamics were analyzed using positron emission tomography (PET) following an intravenous injection of 1,000 MBq [15O]H2O synthesized on-line. RESULTS: Water influx into CSF in AD patients expressed as influx ratio (0.761±0.009) is significantly reduced (p < 0.001) compared to young controls (1.329 ±0.218). Senior controls showed a large range of influx ratio (0.599-1.442) suggesting that reduction in water influx into CSF represents one of the “aging” processes. CONCLUSIONS: Reduction in water influx into the CSF and clearance rate of β-amyloid is the necessary, if not sufficient, factor in pathogenesis of AD. Cohort studies for assessing dynamical indices of the balance between production and clearance of β-amyloid among various populations, including mild cognitive impairment (MCI) patients appears to be critical for our proper understanding of the pathogenesis of AD. Study Supported by: Ministry of Education, Culture, Sports, Science, and Technology (Japan) Disclosure: Dr. Nakada has nothing to disclose. Dr. Igarashi has nothing to disclose. Dr. Suzuki has nothing to disclose. Dr. Kwee has nothing to disclose.
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water influx into cerebrospinal fluid is primarily controlled by aquaporin 4 not by aquaporin 1 17o jjvcpe mri study in knockout mice
Neuroreport, 2013Co-Authors: Hironaka Igarashi, Ingrid L Kwee, Tsutomu Nakada, Mika TsujitaAbstract:Recent studies on cerebrospinal fluid (CSF) homeostasis emphasize the importance of water flux through the pericapillary (Virchow–Robin) Space for both CSF production and reabsorption (Oreskovic and Klarica hypothesis), and challenge the classic CSF circulation theory, which proposes that CSF is primarily produced by the choroid plexus and reabsorbed by the arachnoid villi. Active suppression of aquaporin-1 (AQP-1) expression within brain capillaries and preservation of AQP-1 within the choroid plexus together with pericapillary water regulation by AQP-4 provide a unique opportunity for testing this recent hypothesis. We investigated water flux into three representative regions of the brain, namely, the cortex, basal ganglia, and third ventricle using a newly developed water molecular MRI technique based on JJ vicinal coupling between 17O and adjacent protons and water molecule proton exchanges (JJVCPE imaging) in AQP-1 and AQP-4 knockout mice in vivo. The results clearly indicate that water influx into the CSF is regulated by AQP-4, and not by AQP-1, strongly supporting the Oreskovic and Klarica hypothesis.
Miklos Schneider - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of lymphatic vessel dilatations by anterior segment swept-source optical coherence tomography: case report
BMC Ophthalmology, 2017Co-Authors: Eva Volek, Jeannette Toth, Zoltan Zsolt Nagy, Miklos SchneiderAbstract:Background Conjunctival lymphangiectasia is a rare condition presumably caused by the obstruction of lymphatic channels or by an abnormal connection between conjunctival lymphatic and blood vessels. Diagnosis is based on clinical appearance and histology. We report a case of conjunctival lymphangiectasia in which anterior segment optical coherence tomography (OCT) was used to assist the diagnosis and the planning of the biopsy location. Case presentation A 31-year-old woman was referred with repeated episodes of conjunctival “hemorrhages” and chemosis with extended recovery periods over the last months. Other symptoms were dryness, redness, burning sensation and itching. Photo documentation, anterior segment OCT, ultrasound, computer tomography (CT) and magnetic resonance imaging (MRI) of the brain were performed. MRI revealed dilated atypical Virchow-Robin Space (VRS). Conjunctival biopsy was taken and the location of the biopsy was selected based on OCT findings. Based on the clinical appearance we suspected the case to be conjunctival lymphangiectasia or lymphangioma. Histology and immunhistochemistry confirmed the diagnosis of conjunctival lymphangiectasia. Conclusions Anterior segment OCT is a non-invasive tool, useful in the evaluation of conjunctival lesions and planning surgery.
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Evaluation of lymphatic vessel dilatations by anterior segment swept-source optical coherence tomography: case report
BMC ophthalmology, 2017Co-Authors: Volek E, Jeannette Toth, Zoltán Nagy, Miklos SchneiderAbstract:Conjunctival lymphangiectasia is a rare condition presumably caused by the obstruction of lymphatic channels or by an abnormal connection between conjunctival lymphatic and blood vessels. Diagnosis is based on clinical appearance and histology. We report a case of conjunctival lymphangiectasia in which anterior segment optical coherence tomography (OCT) was used to assist the diagnosis and the planning of the biopsy location. A 31-year-old woman was referred with repeated episodes of conjunctival “hemorrhages” and chemosis with extended recovery periods over the last months. Other symptoms were dryness, redness, burning sensation and itching. Photo documentation, anterior segment OCT, ultrasound, computer tomography (CT) and magnetic resonance imaging (MRI) of the brain were performed. MRI revealed dilated atypical Virchow-Robin Space (VRS). Conjunctival biopsy was taken and the location of the biopsy was selected based on OCT findings. Based on the clinical appearance we suspected the case to be conjunctival lymphangiectasia or lymphangioma. Histology and immunhistochemistry confirmed the diagnosis of conjunctival lymphangiectasia. Anterior segment OCT is a non-invasive tool, useful in the evaluation of conjunctival lesions and planning surgery.
