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Michael S Kook - One of the best experts on this subject based on the ideXlab platform.
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relationship between 24 hour mean ocular perfusion pressure fluctuation and rate of paracentral visual field progression in normal tension glaucoma
Investigative Ophthalmology & Visual Science, 2013Co-Authors: Jaewan Choi, Jong Rak Lee, Youngrok Lee, Kyoung Sub Lee, Seungbong Han, Michael S KookAbstract:PURPOSE To investigate the relationship between unstable mean ocular perfusion pressure (MOPP) and the rate of paracentral visual field (PVF) progression in patients with medically treated normal-tension glaucoma (NTG). METHODS The data of 157 eyes of 122 patients with NTG who were followed for more than 6 years (mean follow-up, 8.7 years ± 12.6 months) and had more than 5 reliable standard visual field (VF) tests were analyzed retrospectively. Groups in the highest, middle, and lowest tertiles of 24-hour MOPP fluctuation (HMF, Mmf, and LMF, respectively) were compared in terms of rates of change of mean thresholds in the central 10° (PVF), 10° to 24°, and global areas by using a linear mixed model. Clinical factors associated with rapid PVF progression were also investigated. RESULTS The LMF and HMF groups did not differ significantly in the mean global rate of VF changes (-0.52 vs. -0.71 dB/y; P = 0.07). The HMF group had a significantly faster progression of VF defects in the central 10° area than the LMF group (-1.02 vs. -0.54 dB/y; P < 0.001) but did not differ in terms of progression of VF defects in the peripheral 10° to 24° area (-0.39 vs. -0.495 dB/y; P = 0.425). PVF progression was significantly associated with 24-hour MOPP fluctuation (β = -0.31, P < 0.001) and VF damage severity at initial presentation (β = 0.134, P = 0.011). CONCLUSIONS Medically treated NTG eyes with greater 24-hour MOPP fluctuations (HMF) had faster PVF defect progression than eyes with stable 24-hour MOPP (LMF). Twenty-four hour MOPP fluctuation associated significantly with PVF progression velocity.
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characteristics of visual field progression in medically treated normal tension glaucoma patients with unstable ocular perfusion pressure
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kyung Rim Sung, Jaewan Choi, Youngrok Lee, Jung Woo Cho, Suhwan Lee, Sungcheol Yun, Michael S KookAbstract:PURPOSE To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). METHODS One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. RESULTS Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). CONCLUSIONS The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.
Jaewan Choi - One of the best experts on this subject based on the ideXlab platform.
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relationship between 24 hour mean ocular perfusion pressure fluctuation and rate of paracentral visual field progression in normal tension glaucoma
Investigative Ophthalmology & Visual Science, 2013Co-Authors: Jaewan Choi, Jong Rak Lee, Youngrok Lee, Kyoung Sub Lee, Seungbong Han, Michael S KookAbstract:PURPOSE To investigate the relationship between unstable mean ocular perfusion pressure (MOPP) and the rate of paracentral visual field (PVF) progression in patients with medically treated normal-tension glaucoma (NTG). METHODS The data of 157 eyes of 122 patients with NTG who were followed for more than 6 years (mean follow-up, 8.7 years ± 12.6 months) and had more than 5 reliable standard visual field (VF) tests were analyzed retrospectively. Groups in the highest, middle, and lowest tertiles of 24-hour MOPP fluctuation (HMF, Mmf, and LMF, respectively) were compared in terms of rates of change of mean thresholds in the central 10° (PVF), 10° to 24°, and global areas by using a linear mixed model. Clinical factors associated with rapid PVF progression were also investigated. RESULTS The LMF and HMF groups did not differ significantly in the mean global rate of VF changes (-0.52 vs. -0.71 dB/y; P = 0.07). The HMF group had a significantly faster progression of VF defects in the central 10° area than the LMF group (-1.02 vs. -0.54 dB/y; P < 0.001) but did not differ in terms of progression of VF defects in the peripheral 10° to 24° area (-0.39 vs. -0.495 dB/y; P = 0.425). PVF progression was significantly associated with 24-hour MOPP fluctuation (β = -0.31, P < 0.001) and VF damage severity at initial presentation (β = 0.134, P = 0.011). CONCLUSIONS Medically treated NTG eyes with greater 24-hour MOPP fluctuations (HMF) had faster PVF defect progression than eyes with stable 24-hour MOPP (LMF). Twenty-four hour MOPP fluctuation associated significantly with PVF progression velocity.
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characteristics of visual field progression in medically treated normal tension glaucoma patients with unstable ocular perfusion pressure
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kyung Rim Sung, Jaewan Choi, Youngrok Lee, Jung Woo Cho, Suhwan Lee, Sungcheol Yun, Michael S KookAbstract:PURPOSE To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). METHODS One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. RESULTS Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). CONCLUSIONS The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.
Sghaier Randa - One of the best experts on this subject based on the ideXlab platform.
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Caractérisation des activités cytoprotectrices de molécules utilisées dans le traitement de la sclérose en plaques (diméthyle fumarate, monométhyle fumarate, biotine) sur des oligodendrocytes 158N : impact sur le stress oxydant, le statut mitochondri
HAL CCSD, 2019Co-Authors: Sghaier RandaAbstract:Oxidative stress, mitochondrial dysfunction, and alterations in lipid metabolism are a common denominator of neurodegenerative diseases (MN), such as multiple sclerosis (MS). Under oxidative stress conditions, excess cholesterol is removed by oxidation, producing oxysterols. In humans, the 7β-hydroxycholesterol (7β-OHC) is often found at increased levels in the cerebrospinal fluid (CSF) and/or plasma of patients with MN, including MS.In this context, a preliminary clinical study on CSF and plasma of patients with RR MS was carried out to search for lipid metabolism and oxidative stress biomarkers and to determine the possible correlations between 7β-OHC and the different mechanisms associated with the MS pathogenesis. An in vitro study was conducted to evaluate the biological activities of three molecules used in the treatment of MS, dimethyl fumarate (DMF) and its major metabolite, monomethyl fumarate (Mmf), and biotin on 158N murine oligodendrocytes, and to determine their cytoprotective potentialities by focusing on their ability to oppose the toxicity of 7β-OHC. For this, spectrophotometric, analytical and molecular biology techniques were used.Our results have shown an increased level of HODE associated with an enhancement of oxysterol levels in the plasma, notably 7KC and 7β-OHC, as well an alteration in fatty acid metabolism in the CSF and plasma of patients with SEP. The in vitro study revealed that DMF, Mmf, and biotin can counteract the deleterious effects of 7β-OHC namely; cell death by oxiapoptophagy defined by the association of apoptosis, autophagy and oxidative stress. Moreover, these molecules correct the structural modifications and the disequilibrium of the redox status characterized by an overproduction of radical oxygen species, an increased activity of the principal antioxidant enzymes and an amplification of the macromolecules oxidation induced by the 7β- OHC. They also attenuate the mitochondrial and peroxisomal dysfunctions, the alterations of myelin protein expression as well as the lipid profile disorder induced by 7β-OHC.Our study provides arguments in favor of the ability of DMF, Mmf, and biotin, to attenuate the major events associated with the death of oligodendrocytes which could contribute to demyelination. This reinforces the interest in these molecules for the treatment of neurodegenerative diseases including MS.Le stress oxydant, les dysfonctions mitochondriaux et les altérations du métabolisme lipidique sont un dénominateur commun des maladies neurodégénératives (MN), comme la sclérose en plaques (SEP). Dans les conditions du stress oxydant, l’excès du cholestérol est éliminé par oxydation, produisant des oxystérols. Chez l'homme, le taux du 7β-hydroxycholestérol (7β-OHC) est souvent trouvé à des taux élevés dans le liquide céphalo-rachidien (LCR) et/ ou le plasma de patients atteints de MN, notamment la SEP.Dans ce contexte, une étude clinique préliminaire sur le LCR et le plasma de patients atteints de SEP RR a été réalisée dans le but de rechercher des biomarqueurs du métabolisme lipidique et du stress oxydant et de déterminer d‘éventuelles corrélations entre le 7β-OHC et les différents mécanismes associés à la pathogenèse de la SEP. Une étude in vitro a été réalisée afin d’évaluer les activités biologiques de trois molécules utilisées dans le traitement de la SEP, le diméthyle fumarate (DMF) et son métabolite le monométhyle fumarate (Mmf), et la biotine sur des oligodendrocytes murins 158N, et à déterminer leurs potentialités cytoprotectrices en se focalisant sur leurs capacités à s’opposer à la toxicité du 7β-OHC. Pour cela, des techniques spectrophotométriques, analytiques et de biologies moléculaires ont été utilisées.Nos résultats ont révélé une augmentation du taux de HODE associée à une augmentation du taux plasmatiques d’oxystérols, notamment 7KC et 7β-OHC, ainsi qu’une altération du métabolisme d’acides gras au niveau du LCR et du plasma des patients atteints de SEP. L’étude in vitro a montré que le DMF, le Mmf et la biotine présentent des capacités à atténuer les effets délétères du 7β-OHC à savoir; la mort cellulaire par oxiapoptophagie définie par l’association de l’apoptose, l’autophagie et le stress oxydant. De plus, ces molécules corrigent les modifications structurales et le déséquilibre du statut redox caractérisé par une surproduction d’espèces radicalaires d’oxygène, une activité accrue des principales enzymes anti-oxydantes et une amplification de l'oxydation de macromolécules induites par le 7β-OHC. Elles atténuent également les dysfonctionnements mitochondriaux et péroxysomaux, les altérations de l’expression de protéines de myéline ainsi que le désordre du profil lipidique, induits par le 7β-OHC.Notre étude apporte des arguments en faveurs de la capacité du DMF, du Mmf et de la biotine, à atténuer les phénomènes majeurs associés à la mort des oligodendrocytes qui pourraient contribuer à la démyélinisation. Ceci renforce l'intérêt porté à ces molécules pour le traitement des maladies neurodégénératives incluant la SEP
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Characterization of the cytoprotective activities of molecules used in the treatment of multiple sclerosis (dimethyl fumarate, monomethyl fumarate, biotin) on 158N oligodendrocytes : impact on oxidative stress, mitochondrial status, lipid status, apo
2019Co-Authors: Sghaier RandaAbstract:Le stress oxydant, les dysfonctions mitochondriaux et les altérations du métabolisme lipidique sont un dénominateur commun des maladies neurodégénératives (MN), comme la sclérose en plaques (SEP). Dans les conditions du stress oxydant, l’excès du cholestérol est éliminé par oxydation, produisant des oxystérols. Chez l'homme, le taux du 7β-hydroxycholestérol (7β-OHC) est souvent trouvé à des taux élevés dans le liquide céphalo-rachidien (LCR) et/ ou le plasma de patients atteints de MN, notamment la SEP.Dans ce contexte, une étude clinique préliminaire sur le LCR et le plasma de patients atteints de SEP RR a été réalisée dans le but de rechercher des biomarqueurs du métabolisme lipidique et du stress oxydant et de déterminer d‘éventuelles corrélations entre le 7β-OHC et les différents mécanismes associés à la pathogenèse de la SEP. Une étude in vitro a été réalisée afin d’évaluer les activités biologiques de trois molécules utilisées dans le traitement de la SEP, le diméthyle fumarate (DMF) et son métabolite le monométhyle fumarate (Mmf), et la biotine sur des oligodendrocytes murins 158N, et à déterminer leurs potentialités cytoprotectrices en se focalisant sur leurs capacités à s’opposer à la toxicité du 7β-OHC. Pour cela, des techniques spectrophotométriques, analytiques et de biologies moléculaires ont été utilisées.Nos résultats ont révélé une augmentation du taux de HODE associée à une augmentation du taux plasmatiques d’oxystérols, notamment 7KC et 7β-OHC, ainsi qu’une altération du métabolisme d’acides gras au niveau du LCR et du plasma des patients atteints de SEP. L’étude in vitro a montré que le DMF, le Mmf et la biotine présentent des capacités à atténuer les effets délétères du 7β-OHC à savoir; la mort cellulaire par oxiapoptophagie définie par l’association de l’apoptose, l’autophagie et le stress oxydant. De plus, ces molécules corrigent les modifications structurales et le déséquilibre du statut redox caractérisé par une surproduction d’espèces radicalaires d’oxygène, une activité accrue des principales enzymes anti-oxydantes et une amplification de l'oxydation de macromolécules induites par le 7β-OHC. Elles atténuent également les dysfonctionnements mitochondriaux et péroxysomaux, les altérations de l’expression de protéines de myéline ainsi que le désordre du profil lipidique, induits par le 7β-OHC.Notre étude apporte des arguments en faveurs de la capacité du DMF, du Mmf et de la biotine, à atténuer les phénomènes majeurs associés à la mort des oligodendrocytes qui pourraient contribuer à la démyélinisation. Ceci renforce l'intérêt porté à ces molécules pour le traitement des maladies neurodégénératives incluant la SEP.Oxidative stress, mitochondrial dysfunction, and alterations in lipid metabolism are a common denominator of neurodegenerative diseases (MN), such as multiple sclerosis (MS). Under oxidative stress conditions, excess cholesterol is removed by oxidation, producing oxysterols. In humans, the 7β-hydroxycholesterol (7β-OHC) is often found at increased levels in the cerebrospinal fluid (CSF) and/or plasma of patients with MN, including MS.In this context, a preliminary clinical study on CSF and plasma of patients with RR MS was carried out to search for lipid metabolism and oxidative stress biomarkers and to determine the possible correlations between 7β-OHC and the different mechanisms associated with the MS pathogenesis. An in vitro study was conducted to evaluate the biological activities of three molecules used in the treatment of MS, dimethyl fumarate (DMF) and its major metabolite, monomethyl fumarate (Mmf), and biotin on 158N murine oligodendrocytes, and to determine their cytoprotective potentialities by focusing on their ability to oppose the toxicity of 7β-OHC. For this, spectrophotometric, analytical and molecular biology techniques were used.Our results have shown an increased level of HODE associated with an enhancement of oxysterol levels in the plasma, notably 7KC and 7β-OHC, as well an alteration in fatty acid metabolism in the CSF and plasma of patients with SEP. The in vitro study revealed that DMF, Mmf, and biotin can counteract the deleterious effects of 7β-OHC namely; cell death by oxiapoptophagy defined by the association of apoptosis, autophagy and oxidative stress. Moreover, these molecules correct the structural modifications and the disequilibrium of the redox status characterized by an overproduction of radical oxygen species, an increased activity of the principal antioxidant enzymes and an amplification of the macromolecules oxidation induced by the 7β- OHC. They also attenuate the mitochondrial and peroxisomal dysfunctions, the alterations of myelin protein expression as well as the lipid profile disorder induced by 7β-OHC.Our study provides arguments in favor of the ability of DMF, Mmf, and biotin, to attenuate the major events associated with the death of oligodendrocytes which could contribute to demyelination. This reinforces the interest in these molecules for the treatment of neurodegenerative diseases including MS
Biyun Liu - One of the best experts on this subject based on the ideXlab platform.
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synergistic control of internal phosphorus loading from eutrophic lake sediment using Mmf coupled with submerged macrophytes
Science of The Total Environment, 2020Co-Authors: Zisen Liu, Yi Zhang, Pan Yan, Ji Luo, Lingwei Kong, Junjun Chang, Biyun LiuAbstract:Abstract Sediment phosphorus (P) is the main source of endogenous P for lake eutrophication. An in-situ combined technology for determination the removal effect of sediment P in all fractions was first developed using the novel modified maifanite (Mmf) and submerged macrophytes in this study. Mmf was synthesized using an acidification process (2.5 mol/L H2SO4) and then a calcination (400 °C) method. The morphology and structure of Mmf were characterized by XRD, SEM, XPS, and BET. We tested the removal effects of sediment P by Mmf and submerged macrophytes in combination and separately. The results demonstrated that the synergistic removal capacity of sediment P using Mmf coupled with submerged macrophytes was higher than the sum of them applied separately. Mmf could promote the submerged macrophytes growth and enhance the adsorption of extra P on Mmf through root oxygenation and nutrient allocation. The microcosm experiment results showed that sediment from fMmf+V. spiralis exhibited the most microbial diversity and abundance among the sediment. The combination of Mmf and submerged macrophytes increased the Firmicutes abundance and decreased the Bacteroidetes. These results indicated that adsorption-biological technology can be regarded as a novel and competitive technology to the endogenous pollution control in eutrophic shallow lakes.
Youngrok Lee - One of the best experts on this subject based on the ideXlab platform.
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relationship between 24 hour mean ocular perfusion pressure fluctuation and rate of paracentral visual field progression in normal tension glaucoma
Investigative Ophthalmology & Visual Science, 2013Co-Authors: Jaewan Choi, Jong Rak Lee, Youngrok Lee, Kyoung Sub Lee, Seungbong Han, Michael S KookAbstract:PURPOSE To investigate the relationship between unstable mean ocular perfusion pressure (MOPP) and the rate of paracentral visual field (PVF) progression in patients with medically treated normal-tension glaucoma (NTG). METHODS The data of 157 eyes of 122 patients with NTG who were followed for more than 6 years (mean follow-up, 8.7 years ± 12.6 months) and had more than 5 reliable standard visual field (VF) tests were analyzed retrospectively. Groups in the highest, middle, and lowest tertiles of 24-hour MOPP fluctuation (HMF, Mmf, and LMF, respectively) were compared in terms of rates of change of mean thresholds in the central 10° (PVF), 10° to 24°, and global areas by using a linear mixed model. Clinical factors associated with rapid PVF progression were also investigated. RESULTS The LMF and HMF groups did not differ significantly in the mean global rate of VF changes (-0.52 vs. -0.71 dB/y; P = 0.07). The HMF group had a significantly faster progression of VF defects in the central 10° area than the LMF group (-1.02 vs. -0.54 dB/y; P < 0.001) but did not differ in terms of progression of VF defects in the peripheral 10° to 24° area (-0.39 vs. -0.495 dB/y; P = 0.425). PVF progression was significantly associated with 24-hour MOPP fluctuation (β = -0.31, P < 0.001) and VF damage severity at initial presentation (β = 0.134, P = 0.011). CONCLUSIONS Medically treated NTG eyes with greater 24-hour MOPP fluctuations (HMF) had faster PVF defect progression than eyes with stable 24-hour MOPP (LMF). Twenty-four hour MOPP fluctuation associated significantly with PVF progression velocity.
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characteristics of visual field progression in medically treated normal tension glaucoma patients with unstable ocular perfusion pressure
Investigative Ophthalmology & Visual Science, 2011Co-Authors: Kyung Rim Sung, Jaewan Choi, Youngrok Lee, Jung Woo Cho, Suhwan Lee, Sungcheol Yun, Michael S KookAbstract:PURPOSE To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). METHODS One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. RESULTS Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). CONCLUSIONS The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.