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Hans Persson - One of the best experts on this subject based on the ideXlab platform.

  • changes in ultrastructure and function of the sheep Pigment Epithelium and retina induced by sodium iodate ii early effects
    Acta Ophthalmologica, 2009
    Co-Authors: Sven G Nilsson, Bengt Knave, Hans Persson
    Abstract:

    The delayed effects on the sheep Pigment Epithelium and retina of sodium iodate, as studied three days after the injection, included electrophysiological as well as morphological changes. The c-wave of the ERG was abolished, and the a- and b-waves were substantially reduced in amplitude, which was also the case as early as about 100–150 min after the injection. The cornea-negative potential earlier having replaced the c-wave was no longer present, however. In addition to changes in the Pigment Epithelium seen already at an earlier stage, marked ultrastructural damage was observed also in the neuroretina, particularly in the photoreceptor cells and the Muller cells, but involving all layers except the ganglion cell axons. The receptor outer segments were greatly vesiculated and disorganized and the inner segments vacuolized. The more vitread cells of the retina showed various degrees of oedema with distended mitochondria and a reduced amount of cytoplasmic structures. It appears that the effects on the neuroretina of sodium iodate are to a great extent caused by the insufficient membrane and metabolic properties of the Pigment Epithelium. From this series of three papers it can be concluded that sodium iodate primarily damaged the Pigment Epithelium, thereby destroying the structural organization of the latter and abolishing the c-wave. Later the neuro-retina was affected, first in the form of a- and b-wave reductions and then also as ultrastructural changes. It thus seems that the early stage after injection of sodium iodate may provide a valuable possibility of studying the electrophysiological effects on the neuroretina of various drugs without interference of the potentials from the Pigment Epithelium.

  • changes in ultrastructure and function of the sheep Pigment Epithelium and retina induced by sodium iodate iii delayed effects
    Acta Ophthalmologica, 2009
    Co-Authors: Sven G Nilsson, Bengt Knave, Hans Persson
    Abstract:

    The delayed effects on the sheep Pigment Epithelium and retina of sodium iodate, as studied three days after the injection, included electrophysiological as well as morphological changes. The c-wave of the ERG was abolished, and the a- and b-waves were substantially reduced in amplitude, which was also the case as early as about 100–150 min after the injection. The cornea-negative potential earlier having replaced the c-wave was no longer present, however. In addition to changes in the Pigment Epithelium seen already at an earlier stage, marked ultrastructural damage was observed also in the neuroretina, particularly in the photoreceptor cells and the Muller cells, but involving all layers except the ganglion cell axons. The receptor outer segments were greatly vesiculated and disorganized and the inner segments vacuolized. The more vitread cells of the retina showed various degrees of oedema with distended mitochondria and a reduced amount of cytoplasmic structures. It appears that the effects on the neuroretina of sodium iodate are to a great extent caused by the insufficient membrane and metabolic properties of the Pigment Epithelium. From this series of three papers it can be concluded that sodium iodate primarily damaged the Pigment Epithelium, thereby destroying the structural organization of the latter and abolishing the c-wave. Later the neuro-retina was affected, first in the form of a- and b-wave reductions and then also as ultrastructural changes. It thus seems that the early stage after injection of sodium iodate may provide a valuable possibility of studying the electrophysiological effects on the neuroretina of various drugs without interference of the potentials from the Pigment Epithelium.

Lucian V Del Priore - One of the best experts on this subject based on the ideXlab platform.

  • use of iris Pigment Epithelium to replace retinal Pigment Epithelium in age related macular degeneration a gene expression analysis
    Archives of Ophthalmology, 2006
    Co-Authors: Min C. Shin, Tongalp H Tezel, Henry J Kaplan, Lucian V Del Priore
    Abstract:

    Objective To determine the gene expression profiles of primary retinal Pigment Epithelium (RPE) and iris Pigment Epithelium (IPE) using microarrays. Methods Primary RPE and IPE from 6 human donor eyes were collected, and total RNA was isolated. Differences in gene expression were determined using a human genechip (human U95Av2 [12 600 probes]; Affymetrix Inc, Santa Clara, Calif). Results Hierarchical cluster analysis differentiated the gene expression profiles of RPE and IPE clusters into 2 distinct groups. A mean ± SD of 5308 ± 416 gene probes were expressed in RPE vs 6130 ± 205 in IPE. Sixty-eight genes were expressed only in RPE; 154 genes were expressed only in IPE. Twenty-two additional genes had greater than 3-fold increased expression in RPE vs IPE, and 147 genes had greater than 3-fold decreased expression in RPE vs IPE. Conclusion There are major differences in the gene expression profiles of primary RPE vs IPE. Clinical Relevance The different gene expression profiles of primary RPE vs IPE harvested from the same donor eyes infer that it may be difficult for IPE to replace all aspects of damaged RPE function in transplantation studies.

  • tissue culture of retinal Pigment Epithelium following isolation with a gelatin matrix technique
    Experimental Eye Research, 1997
    Co-Authors: Tzyychang Ho, Lucian V Del Priore, Henry J Kaplan
    Abstract:

    Abstract Prior to transplantation of the retinal Pigment Epithelium, it is necessary to develop techniques to harvest viable retinal Pigment Epithelium as an organized monolayer. Unfortunately, current techniques result in contraction of the harvested monolayer and coiling of the cell sheets, which hinders successful transplantation. The purpose of this study was to develop a method for harvesting retinal Pigment Epithelium from eye cups and from tissue culture prior to transplantation. Passage 1 porcine retinal Pigment Epithelium and native retinal Pigment Epithelium from fresh porcine eye cups were pretreated with 0.25% edetic acid for 12 minutes and coated with a 100 micron layer of 12£ gelatin. Patches of the retinal Pigment epithelial cell monolayer were harvested and transferred to culture plates, and cell viability and the ability of the transferred cells to proliferate in culture was determined. Our results demonstrated that retinal Pigment Epithelium can be harvested from tissue culture and eye cups as an organized monolayer with high efficiency (94.7±3.5% and 99.7±0.3% harvesting rates, respectively) and high cell viability (91.3±2.9% and 89.4±4.3%, respectively). Cells harvested from tissue culture plates divided and became confluent within 10 to 14 days. Cells harvested from eye cups maintained a differentiated phenotype and migrated outward from the margin of the exoplant. There was no contraction of the retinal Pigment epithelial monolayer isolated from either substrate. Thus, we were able to harvest retinal Pigment Epithelium as an organized monolayer from tissue culture plates and freshly enucleated eyes with edetic acid and gelatin. The harvested cells were viable and proliferated without contraction of the monolayer in vitro .

Henry J Kaplan - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of focal damage in the retinal Pigment Epithelium layer in serous retinal Pigment Epithelium detachment
    Nature Publishing Group, 2019
    Co-Authors: Masahiro Miura, Shuichi Makita, Shinnosuke Azuma, Yoshiaki Yasuno, Shunichiro Ueda, Satoshi Sugiyama, Toshihiro Mino, Tatsuo Yamaguchi, Harpal S. Sandhu, Henry J Kaplan
    Abstract:

    Abstract The purpose of this study was to evaluate focal damage in the retinal Pigment Epithelium (RPE) layer in serous retinal Pigment Epithelium detachment (PED) with multi-contrast optical coherence tomography (OCT), which is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT and standard OCT images. We evaluated 37 eyes with age-related macular degeneration that had serous PED. Focal RPE damage was indicated by hyper-transmission beneath the RPE-Bruch’s membrane band in standard OCT images. Distribution of RPE melanin was calculated using the dataset from multi-contrast OCT. Twenty-four points with hyper-transmission were detected in 21 of the 37 eyes. Standard OCT images failed to show disruption of the RPE-Bruch’s membrane band at 5 of the 24 hyper-transmission points. Conversely, multi-contrast OCT images clearly showed melanin defects in the RPE-Bruch’s membrane band at all points. Areas of melanin defects with disruption of the RPE-Bruch’s membrane band were significantly larger than those without disruption. The volume of intraretinal hyper-reflective foci was significantly larger in eyes with hyper-transmission than that in eyes without hyper-transmission. Multi-contrast OCT is more sensitive than standard OCT for displaying changes at the RPE-Bruch’s membrane band when there are small areas of RPE damage

  • use of iris Pigment Epithelium to replace retinal Pigment Epithelium in age related macular degeneration a gene expression analysis
    Archives of Ophthalmology, 2006
    Co-Authors: Min C. Shin, Tongalp H Tezel, Henry J Kaplan, Lucian V Del Priore
    Abstract:

    Objective To determine the gene expression profiles of primary retinal Pigment Epithelium (RPE) and iris Pigment Epithelium (IPE) using microarrays. Methods Primary RPE and IPE from 6 human donor eyes were collected, and total RNA was isolated. Differences in gene expression were determined using a human genechip (human U95Av2 [12 600 probes]; Affymetrix Inc, Santa Clara, Calif). Results Hierarchical cluster analysis differentiated the gene expression profiles of RPE and IPE clusters into 2 distinct groups. A mean ± SD of 5308 ± 416 gene probes were expressed in RPE vs 6130 ± 205 in IPE. Sixty-eight genes were expressed only in RPE; 154 genes were expressed only in IPE. Twenty-two additional genes had greater than 3-fold increased expression in RPE vs IPE, and 147 genes had greater than 3-fold decreased expression in RPE vs IPE. Conclusion There are major differences in the gene expression profiles of primary RPE vs IPE. Clinical Relevance The different gene expression profiles of primary RPE vs IPE harvested from the same donor eyes infer that it may be difficult for IPE to replace all aspects of damaged RPE function in transplantation studies.

  • tissue culture of retinal Pigment Epithelium following isolation with a gelatin matrix technique
    Experimental Eye Research, 1997
    Co-Authors: Tzyychang Ho, Lucian V Del Priore, Henry J Kaplan
    Abstract:

    Abstract Prior to transplantation of the retinal Pigment Epithelium, it is necessary to develop techniques to harvest viable retinal Pigment Epithelium as an organized monolayer. Unfortunately, current techniques result in contraction of the harvested monolayer and coiling of the cell sheets, which hinders successful transplantation. The purpose of this study was to develop a method for harvesting retinal Pigment Epithelium from eye cups and from tissue culture prior to transplantation. Passage 1 porcine retinal Pigment Epithelium and native retinal Pigment Epithelium from fresh porcine eye cups were pretreated with 0.25% edetic acid for 12 minutes and coated with a 100 micron layer of 12£ gelatin. Patches of the retinal Pigment epithelial cell monolayer were harvested and transferred to culture plates, and cell viability and the ability of the transferred cells to proliferate in culture was determined. Our results demonstrated that retinal Pigment Epithelium can be harvested from tissue culture and eye cups as an organized monolayer with high efficiency (94.7±3.5% and 99.7±0.3% harvesting rates, respectively) and high cell viability (91.3±2.9% and 89.4±4.3%, respectively). Cells harvested from tissue culture plates divided and became confluent within 10 to 14 days. Cells harvested from eye cups maintained a differentiated phenotype and migrated outward from the margin of the exoplant. There was no contraction of the retinal Pigment epithelial monolayer isolated from either substrate. Thus, we were able to harvest retinal Pigment Epithelium as an organized monolayer from tissue culture plates and freshly enucleated eyes with edetic acid and gelatin. The harvested cells were viable and proliferated without contraction of the monolayer in vitro .

Sven G Nilsson - One of the best experts on this subject based on the ideXlab platform.

  • changes in ultrastructure and function of the sheep Pigment Epithelium and retina induced by sodium iodate ii early effects
    Acta Ophthalmologica, 2009
    Co-Authors: Sven G Nilsson, Bengt Knave, Hans Persson
    Abstract:

    The delayed effects on the sheep Pigment Epithelium and retina of sodium iodate, as studied three days after the injection, included electrophysiological as well as morphological changes. The c-wave of the ERG was abolished, and the a- and b-waves were substantially reduced in amplitude, which was also the case as early as about 100–150 min after the injection. The cornea-negative potential earlier having replaced the c-wave was no longer present, however. In addition to changes in the Pigment Epithelium seen already at an earlier stage, marked ultrastructural damage was observed also in the neuroretina, particularly in the photoreceptor cells and the Muller cells, but involving all layers except the ganglion cell axons. The receptor outer segments were greatly vesiculated and disorganized and the inner segments vacuolized. The more vitread cells of the retina showed various degrees of oedema with distended mitochondria and a reduced amount of cytoplasmic structures. It appears that the effects on the neuroretina of sodium iodate are to a great extent caused by the insufficient membrane and metabolic properties of the Pigment Epithelium. From this series of three papers it can be concluded that sodium iodate primarily damaged the Pigment Epithelium, thereby destroying the structural organization of the latter and abolishing the c-wave. Later the neuro-retina was affected, first in the form of a- and b-wave reductions and then also as ultrastructural changes. It thus seems that the early stage after injection of sodium iodate may provide a valuable possibility of studying the electrophysiological effects on the neuroretina of various drugs without interference of the potentials from the Pigment Epithelium.

  • changes in ultrastructure and function of the sheep Pigment Epithelium and retina induced by sodium iodate iii delayed effects
    Acta Ophthalmologica, 2009
    Co-Authors: Sven G Nilsson, Bengt Knave, Hans Persson
    Abstract:

    The delayed effects on the sheep Pigment Epithelium and retina of sodium iodate, as studied three days after the injection, included electrophysiological as well as morphological changes. The c-wave of the ERG was abolished, and the a- and b-waves were substantially reduced in amplitude, which was also the case as early as about 100–150 min after the injection. The cornea-negative potential earlier having replaced the c-wave was no longer present, however. In addition to changes in the Pigment Epithelium seen already at an earlier stage, marked ultrastructural damage was observed also in the neuroretina, particularly in the photoreceptor cells and the Muller cells, but involving all layers except the ganglion cell axons. The receptor outer segments were greatly vesiculated and disorganized and the inner segments vacuolized. The more vitread cells of the retina showed various degrees of oedema with distended mitochondria and a reduced amount of cytoplasmic structures. It appears that the effects on the neuroretina of sodium iodate are to a great extent caused by the insufficient membrane and metabolic properties of the Pigment Epithelium. From this series of three papers it can be concluded that sodium iodate primarily damaged the Pigment Epithelium, thereby destroying the structural organization of the latter and abolishing the c-wave. Later the neuro-retina was affected, first in the form of a- and b-wave reductions and then also as ultrastructural changes. It thus seems that the early stage after injection of sodium iodate may provide a valuable possibility of studying the electrophysiological effects on the neuroretina of various drugs without interference of the potentials from the Pigment Epithelium.

Fiorenzo Mignini - One of the best experts on this subject based on the ideXlab platform.

  • retinal Pigment Epithelium age related macular degeneration and neurotrophic keratouveitis
    International Journal of Molecular Medicine, 2013
    Co-Authors: E. Bianchi, Fabio Scarinci, Rocco Plateroti, Pasquale Plateroti, Guido Ripandelli, Corrado Balacco Gabrieli, Jakub Féher, Elena Pacella, Giuseppe Magliulo, Fiorenzo Mignini
    Abstract:

    : Age-related macular degeneration (AMD) is the leading cause of impaired vision and blindness in the aging population. The aims of our studies were to identify qualitative and quantitative alterations in mitochondria in human retinal Pigment Epithelium (RPE) from AMD patients and controls and to test the protective effects of Pigment Epithelium-derived factor (PEDF), a known neurotrophic and antiangiogenic substance, against neurotrophic keratouveitis. Histopathological alterations were studied by means of morphometry, light and electron microscopy. Unexpectedly, morphometric data showed that the RPE alterations noted in AMD may also develop in normal aging, 10-15 years later than appearing in AMD patients. Reduced tear secretion, corneal ulceration and leukocytic infiltration were found in capsaicin (CAP)-treated rats, but this effect was significantly attenuated by PEDF. These findings suggest that PEDF accelerated the recovery of tear secretion and also prevented neurotrophic keratouveitis and vitreoretinal inflammation. PEDF may have a clinical application in inflammatory and neovascular diseases of the eye.