The Experts below are selected from a list of 3177 Experts worldwide ranked by ideXlab platform
Éva Csősz - One of the best experts on this subject based on the ideXlab platform.
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Changes in the Chemical Barrier Composition of Tears in Alzheimer's Disease Reveal Potential Tear Diagnostic Biomarkers.
PloS one, 2016Co-Authors: Gergő Kalló, Miklós Emri, Zsofia Varga, Bernadett Ujhelyi, József Tőzsér, Adrienne Csutak, Éva CsőszAbstract:Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases, with increasing prevalence affecting millions of people worldwide. Currently, only autopsy is able to confirm the diagnosis with a 100% certainty, therefore, biomarkers from body fluids obtained by non-invasive means provide an attractive alternative for the diagnosis of Alzheimer`s disease. Global changes of the protein profile were examined by quantitative proteomics; firstly, electrophoresis and LC-MS/MS were used, thereafter, SRM-based targeted proteomics method was developed and applied to examine quantitative changes of Tear proteins. Alterations in the Tear Flow rate, total Tear protein concentration and composition of the chemical barrier specific to AD were demonstrated, and the combination of lipocalin-1, dermcidin, lysozyme-C and lacritin was shown to be a potential biomarker, with an 81% sensitivity and 77% specificity.
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Changes in the Chemical Barrier Composition of Tears in Alzheimer’s Disease Reveal Potential Tear Diagnostic Biomarkers
2016Co-Authors: Gergő Kalló, Miklós Emri, Zsofia Varga, Bernadett Ujhelyi, József Tőzsér, Adrienne Csutak, Éva CsőszAbstract:Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases, with increasing prevalence affecting millions of people worldwide. Currently, only autopsy is able to confirm the diagnosis with a 100% certainty, therefore, biomarkers from body fluids obtained by non-invasive means provide an attractive alternative for the diagnosis of Alzheimer`s disease. Global changes of the protein profile were examined by quantitative proteomics; firstly, electrophoresis and LC-MS/MS were used, thereafter, SRM-based targeted proteomics method was developed and applied to examine quantitative changes of Tear proteins. Alterations in the Tear Flow rate, total Tear protein concentration and composition of the chemical barrier specific to AD were demonstrated, and the combination of lipocalin-1, dermcidin, lysozyme-C and lacritin was shown to be a potential biomarker, with an 81% sensitivity and 77% specificity.
Kazuo Tsubota - One of the best experts on this subject based on the ideXlab platform.
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Correlation of Tear clearance rate and fluorophotometric assessment of Tear turnover.
The British journal of ophthalmology, 1995Co-Authors: Kazuo TsubotaAbstract:BACKGROUND--The study sought to determine dynamic changes and theoretical bases of a clinical diagnostic test, the Tear clearance rate. METHODS--Thirty four healthy subjects ranging in age from 22 to 84 years underwent examination of Tear clearance rate, the Schirmer test with anaesthesia, as well as fluorophotometric measurement of Tear turnover, Tear volume, and Tear Flow. By applying 0.5% fluorescein into the conjunctival sac and subsequently measuring colour fades on a Schirmer strip, the Tear clearance rate for assessing Tear drainage was divided into nine grades. The results of the Tear clearance rate were compared with those of the basal Tear turnover and Tear Flow obtained from fluorophotometry. RESULTS--Significant relations were found between the Tear clearance rate and the basal Tear turnover or Tear Flow (r = 0.91 and 0.79, respectively, p = 0.0001). Considering the grades of progression from low to high, each grade of Tear clearance rate showed a 12.5% increase in basal Tear turnover (3.59%/min) and Tear Flow (0.38 microliter/min). There was no significant correlation between age and the basal Tear turnover, Tear volume, Tear Flow, or the Tear clearance rate. CONCLUSION--The Tear clearance rate is proposed as a simple and useful way to estimate basal Tear turnover and Tear Flow, and measure Tear drainage indirectly.
Taagehoj F Jensen - One of the best experts on this subject based on the ideXlab platform.
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methodological aspects of Tear Flow determination by means of a radioactive tracer
Acta Ophthalmologica, 2009Co-Authors: Torben Sorensen, Taagehoj F JensenAbstract:Theoretical considerations on a simplified biological system representing the Tear pathways lead to the assumption of an exponential pattern of elimination of tracer substances from the conjunctival sac. The tracer used in the present study was technetium, Tc99m, as sodium pertechnetate. The detection system consisted of a gamma camera coupled to a digital system, a minicomputer and a magnetic tape unit. After instillation of 10 microliter normal saline solution containing Tc99m the decay of activity was followed by means of an activity-time function curve to which exponential curves were approximated by the computer. As a parameter for Tear Flow the fractional turnover rate was calculated from 7 to 15 min after instillation. An initial faster elimination was found in the first 7 min following instillation. Corrections for background radiation, evaporation of water and transconjunctival transport of Tc99m were estimated.
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Tear Flow in normal human eyes determination by means of radioisotope and gamma camera
Acta Ophthalmologica, 2009Co-Authors: Torben Sorensen, Taagehoj F JensenAbstract:Tear Flow was measured in normal human eyes by means of a radioisotope (technetium as pertechnetate in a normal saline solution), a gamma camera and a computer. By "region of interest" technique the elimination was shown to have two phases: an initial rapid elimination followed by a slower elimination after 5--7 min. The mean fractional turnover rate in the initial phase was 0.197 min.-1 (n = 35, SEM = 0.013) and in the basal phase 0.083 min.-1 (n = 35, SEM = 0.003). Assuming a constant Tear volume these values corresponded to a Tear Flow of 1.4 microliter min.-1 and 0.6 microliter min.-1, respectively. There was no significant difference between the fractional turnover rate in the upright and supine position. No difference was found in Tear Flow between males and females. With the eyes closed the fractional turnover rate was low with intermittently rapid outFlow of Tears. Irritation to the contralateral eye with a filterpaper caused a stimulated Tear Flow of 4.4 microliter min.-1. A nomogram facilitating background corrections was constructed.
Gergő Kalló - One of the best experts on this subject based on the ideXlab platform.
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Changes in the Chemical Barrier Composition of Tears in Alzheimer's Disease Reveal Potential Tear Diagnostic Biomarkers.
PloS one, 2016Co-Authors: Gergő Kalló, Miklós Emri, Zsofia Varga, Bernadett Ujhelyi, József Tőzsér, Adrienne Csutak, Éva CsőszAbstract:Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases, with increasing prevalence affecting millions of people worldwide. Currently, only autopsy is able to confirm the diagnosis with a 100% certainty, therefore, biomarkers from body fluids obtained by non-invasive means provide an attractive alternative for the diagnosis of Alzheimer`s disease. Global changes of the protein profile were examined by quantitative proteomics; firstly, electrophoresis and LC-MS/MS were used, thereafter, SRM-based targeted proteomics method was developed and applied to examine quantitative changes of Tear proteins. Alterations in the Tear Flow rate, total Tear protein concentration and composition of the chemical barrier specific to AD were demonstrated, and the combination of lipocalin-1, dermcidin, lysozyme-C and lacritin was shown to be a potential biomarker, with an 81% sensitivity and 77% specificity.
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Changes in the Chemical Barrier Composition of Tears in Alzheimer’s Disease Reveal Potential Tear Diagnostic Biomarkers
2016Co-Authors: Gergő Kalló, Miklós Emri, Zsofia Varga, Bernadett Ujhelyi, József Tőzsér, Adrienne Csutak, Éva CsőszAbstract:Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases, with increasing prevalence affecting millions of people worldwide. Currently, only autopsy is able to confirm the diagnosis with a 100% certainty, therefore, biomarkers from body fluids obtained by non-invasive means provide an attractive alternative for the diagnosis of Alzheimer`s disease. Global changes of the protein profile were examined by quantitative proteomics; firstly, electrophoresis and LC-MS/MS were used, thereafter, SRM-based targeted proteomics method was developed and applied to examine quantitative changes of Tear proteins. Alterations in the Tear Flow rate, total Tear protein concentration and composition of the chemical barrier specific to AD were demonstrated, and the combination of lipocalin-1, dermcidin, lysozyme-C and lacritin was shown to be a potential biomarker, with an 81% sensitivity and 77% specificity.
Shihchang Wang - One of the best experts on this subject based on the ideXlab platform.
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Tear Flow dynamics in the human nasolacrimal ducts a pilot study using dynamic magnetic resonance imaging
Graefes Archive for Clinical and Experimental Ophthalmology, 2005Co-Authors: Shantha Amrith, Poh Sun Goh, Shihchang WangAbstract:Jones’s theory of Tear drainage suggests that the lacrimal sac fills when the eyelids are closed and empties into the nasolacrimal duct when the eyelids are open. This is aided by the contraction of the orbicularis muscle during each blink. This study was undertaken to ascertain the possibility of seeing the dynamic movement of Tears in the nasolacrimal system during blinks using magnetic resonance dacryocystography (MR-DCG). The sac was initially localized with a three-plane gradient echo sequence using a 1.5-T MRI platform. Fast, dynamic MR-DCG was carried out after we had instilled topically balanced salt solution (BSS) in five subjects and 0.5% gadolinium in seven subjects. The volunteers were asked to close and open their eyes during the fast imaging. The images were digitized to enable us to see the actual movement of fluid in the system. The Tear movement was clearly seen as a bolus in the volunteers where BSS was used. The fluid passed into the nasolacrimal duct after several blinks when patent. The sac was never seen to empty completely. Though differential filling was seen between the upper and lower part of the sac, it was difficult to see the actual fluid movement in the volunteers when topical gadolinium was used. The findings of the study are supportive of the notion of fluid travel in the form of a bolus through the sac. Once a threshold volume is reached in the lower end of the sac, the fluid is seen to pass through the nasolacrimal duct. This happens after several blinks.
