scholarly journals Electron Microscopic Retina Changes in Rabbit Eyes with Perfluorocarbon Liquids Intravitreal Tamponade

2019 ◽  
Vol 16 (1) ◽  
pp. 81-87
Author(s):  
G. M. Arslanov ◽  
B. M. Aznabaev ◽  
T. R. Mukhamadeev ◽  
Z. R. Yanbukhtina ◽  
T. I. Dibaev ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Outer Nuclear Layer ◽  
Vitreous Body ◽  
Vitreous Cavity ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Perfluorocarbon Liquids ◽  
Photoreceptor Neurons ◽  
Epithelium Cells ◽  
Retina Pigment Epithelium

Purpose. Analysis of electron microscopic changes in rabbit eyes with intravitreal tamponade of perfluorocarbon liquids (PFCL) (perfluoro-1,3-dimethylcyclohexane and perfluorodecalin).Material and Methods. The study was performed on Chinchilla breed rabbits. 25G vitrectomy with PFCL intravitreal tamponade was performed on 12 eyes of 6 rabbits (perfluorodecalin (Bausch+Lomb «Dk-line», USA) and perfluoro-1,3-dimethylcyclohexane (ZAO “Optimedservis”, Russia). Standard three-port vitrectomy technique was used. After removal of the vitreous body 2.5 ml of PFCL were injected in vitreous cavity. Research studies were performed in 5, 14 and 30 days after surgery by electron microscopy. Eyes were enucleated in 20 minutes after animal was killed by air embolization. Intact eyes were used as a control. All samples were prepared in same conditions. The damage of the retina architectonics and the presence of intracellular inclusions were evaluated.Results. Tamponade of the vitreous cavity by both types of PFCL in 5, 14 and 30 day caused following similar electron microscopic changes at date: swelling ganglion layer and dystrophy of inner and outer nuclear layer. Electron microscopic changes in outer nuclear layer appeared at 30 days. The photoreceptor neurons were characterized by single ultrastructural changes. Retina pigment epithelium cells had a typical ultrastructure.Conclusion. Intravitreal perfluoro-1,3-dimethylcyclohexane tamponade caused similar electron microscopic changes as well as perfluorodecalin in the experiment and it was relatively harmless to rabbit retina for up to 14 days. Irreversible changes in the retinal ultrastructure were not observed.

scholarly journals High-Salt Enhances the Inflammatory Response by Retina Pigment Epithelium Cells following Lipopolysaccharide Stimulation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Dike Zhang ◽  
Chaokui Wang ◽  
Shuang Cao ◽  
Zi Ye ◽  
Bolin Deng ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Autoimmune Disease ◽  
Osmotic Stress ◽  
P38 Mapk ◽  
Inflammatory Mediators ◽  
Pigment Epithelium ◽  
High Salt ◽  
Stress Control ◽  
Epithelium Cells ◽  
Retina Pigment Epithelium

High-salt has been shown to play a role in the pathogenesis of autoimmune disease. In this study, we investigated the effect of high-salt on the production of inflammatory mediators by ARPE-19 cells and the possible mechanisms involved. ARPE-19 cells were cultured with LPS in DMEM to which extra NaCl had been added (20 mM and 40 mM). NaCl had no influence on the apoptosis and proliferation of ARPE-19. Addition of 40 mM NaCl significantly induced IL-6 and MCP-1 production but had no effect on IL-8 secretion. High mannitol, as an osmotic stress control, did not affect the secretion of inflammatory mediators by ARPE-19 cells indicating that the effect was not mediated by osmolarity. Coculture of ARPE-19 cells with NaCl resulted in significant increases in the phosphorylation of p38 MAPK, Akt, and NF-κB and an upregulation of the transcription factors NFAT5 and SGK1. High-salt significantly promotes IL-6 and MCP-1 production by ARPE-19 cells and is associated with activation of the p38 MAPK, Akt, and NF-κB pathway and NFAT-SGK1 pathways.

scholarly journals UNC569-induced Morphological Changes in Pigment Epithelia and Photoreceptor Cells in the Retina through MerTK Inhibition in Mice

2018 ◽  
Vol 46 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Ayako Sayama ◽  
Keiko Okado ◽  
Koichi Nakamura ◽  
Tatsuya Kawaguchi ◽  
Takuma Iguchi ◽  
...  
Keyword(s):  
Tissue Sample ◽  
Morphological Changes ◽  
Pigment Epithelium ◽  
Outer Nuclear Layer ◽  
Retinal Pigment ◽  
Electron Microscopic Examination ◽  
Photoreceptor Cells ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Photoreceptor Outer Segments

Mer proto-oncogene tyrosine kinase (MerTK), which is expressed in the retinal pigment epithelium (RPE), regulates phagocytosis of shed photoreceptor outer segments (POS). To investigate the effects of drug-induced MerTK inhibition on the retina, UNC569, a specific MerTK inhibitor, was orally administered to male mice at a concentration of 60, 100, or 150 mg/kg for up to 14 days. Furthermore, MerTK inhibition in the retinal tissue sample was examined using a phosphorylation assay following a single dose of UNC569 at 100 mg/kg. In electron microscopic examination, UNC569 at 100 mg/kg or more increased phagosomes and phagolysosomes in the RPE. In addition, UNC569 at 150 mg/kg increased chromatin-condensed nuclei in the outer nuclear layer, indicating the early phase of apoptosis of photoreceptor cells. MiR-183, miR-96, and miR-124, which are enriched in photoreceptor cells, were elevated in the plasma of mice following treatment of 150-mg/kg UNC569, in conjunction with the photoreceptor lesion. Additionally, 100-mg/kg UNC569 inhibited MerTK phosphorylation in the retina. These results suggest that MerTK inhibition impaired phagocytic function of the retina, leading to accumulation of shed POS within the POS layer and increasing phagosomes and phagolysosomes in the RPE to delay POS renewal, resulting in apoptosis of photoreceptor cells.

scholarly journals Protective effects of retinoid x receptors on retina pigment epithelium cells

2016 ◽  
Vol 1863 (6) ◽  
pp. 1134-1145 ◽  
Author(s):  
Victoria Belén Ayala-Peña ◽  
Fiorella Pilotti ◽  
Yanel Volonté ◽  
Nora P. Rotstein ◽  
Luis E. Politi ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Protective Effects ◽  
Retinoid X Receptors ◽  
X Receptors ◽  
Epithelium Cells ◽  
Retina Pigment Epithelium

scholarly journals The Impact of the Timing of Dosing on the Severity of UNC569-Induced Ultrastructural Changes in the Mouse Retina

2020 ◽  
Vol 48 (5) ◽  
pp. 669-676
Author(s):  
Ayako Sayama ◽  
Keiko Okado ◽  
Mayu Yamaguchi ◽  
Naozumi Samata ◽  
Masako Imaoka ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Electron Microscopic Examination ◽  
Photoreceptor Cells ◽  
Ultrastructural Changes ◽  
Mouse Retina ◽  
Visual Cycle ◽  
Electron Microscopic ◽  
The Impact

Mer proto-oncogene tyrosine kinase (MerTK), expressed in the retinal pigment epithelium (RPE), regulates the phagocytosis of shed photoreceptor outer segments. To investigate the influence of dosing time on MerTK inhibitor UNC569-induced retinal toxicity, UNC569 at 100 mg/kg was orally administered to male mice at 2 different Zeitgeber times (ZT5.5 or ZT22) for 28 days. Electron microscopy was conducted at ZT2 after the final dosing. Additionally, the visual cycle components (11-cis-retinal, all-trans-retinal, all-trans-retinol, and 11-cis-retinol), which play an important role in maintaining retinal homeostasis, were quantified by liquid chromatography/mass spectrometry/mass spectrometry. Under electron microscopic examination, the number of phagosomes and phagolysosomes in the RPE increased in both the ZT5.5 and ZT22 administered groups, while endoplasmic reticulum dilatation in the RPE and chromatin aggregation of photoreceptor nuclei were observed only in the ZT22 administered group. No change was observed in any of the visual cycle components. These results suggest that the timing of the dosing in relation to the physiological MerTK phosphorylation affected the severity of changes in the RPE, leading to the apoptosis of the photoreceptor cells.

Ultrastructural Changes of Smoooth Endoplasmic Reticulum in the Retinal Pigment Epithelium by Choline Chloride

1972 ◽  
Vol 30 ◽  
pp. 58-59
Author(s):  
Kazushige Hirosawa ◽  
Eichi Yamada
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cell ◽  
Smooth Endoplasmic Reticulum ◽  
Pigment Epithelium ◽  
Choline Chloride ◽  
Retinal Pigment ◽  
Ultrastructural Changes ◽  
Lower Vertebrate ◽  
Visual Cells ◽  
Pigment Epithelial

The pigment epithelium is located between the choriocapillary and the visual cells. The pigment epithelial cell is characterized by a large amount of the smooth endoplasmic reticulum (SER) in its cytoplasm. In addition, the pigment epithelial cell of some lower vertebrate has myeloid body as a specialized form of the SER. Generally, SER is supposed to work in the lipid metabolism. However, the functions of abundant SER and myeloid body in the pigment epithelial cell are still in question. This paper reports an attempt, to depict the functions of these organelles in the frog retina by administering one of phospholipid precursors.

Morphological and elemental analysis of isolated incubated frog retina-choroid

1984 ◽  
Vol 42 ◽  
pp. 298-299
Author(s):  
B. J. Panessa-Warren ◽  
J. B. Warren ◽  
H. W. Kraner
Keyword(s):  
Elemental Analysis ◽  
Pigment Epithelium ◽  
Human Retina ◽  
Healthy Individuals ◽  
Anterior Portion ◽  
Pathological Conditions ◽  
Frog Retina ◽  
Isolated Retina ◽  
Vertebrate Eye ◽  
Retina Pigment Epithelium

Our previous studies have demonstrated that abnormally high amounts of calcium (Ca) and zinc (Zn) can be accumulated in human retina-choroid under pathological conditions and that barium (Ba), which was not detected in the eyes of healthy individuals, is deposited in the retina pigment epithelium (RPE), and to a lesser extent in the sensory retina and iris. In an attempt to understand how these cations can be accumulated in the vertebrate eye, a morphological and microanalytical study of the uptake and loss of specific cations (K, Ca,Ba,Zn) was undertaken with incubated Rana catesbiana isolated retina and RPE preparations. Large frogs (650-800 gms) were dark adapted, guillotined and their eyes enucleated in deep ruby light. The eyes were hemisected behind the ora serrata and the anterior portion of the eye removed. The eyecup was bisected along the plane of the optic disc and the two segments of retina peeled away from the RPE and incubated.

Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

1990 ◽  
Vol 48 (3) ◽  
pp. 222-223
Author(s):  
T. Shimizu ◽  
Y. Muranaka ◽  
I. Ohta ◽  
N. Honda
Keyword(s):  
Clinical Manifestations ◽  
Quadriceps Muscle ◽  
Honeycomb Structure ◽  
Periodic Paralysis ◽  
Ultrastructural Changes ◽  
Hypokalemic Periodic Paralysis ◽  
Electron Microscopic ◽  
Tubular Aggregates ◽  
Hypokalemic Myopathy ◽  
Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

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