Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Apoptosis of photoreceptor cells in ornithine-induced retinopathy (1998)
    Springer
    Graefe's archive for clinical and experimental ophthalmology 236 (1998), S. 207-212 
    Details
    ISSN: 1435-702X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  • Background: The intravitreal injection of ornithine produces selective damage to the retinal pigment epithelium (RPE) and results in a loss of RPE, choriocapillaris and photoreceptor cells. To elucidate the mechanism of secondary retinal atrophy, we investigated the presence of apoptotic cells in a rat model of ornithine-induced retinopathy. • Methods: At 6 and 12 h and 1, 2, 4, 7, 14 and 28 days after an intravitreal injection of L-ornithine hydrochloride in rat eyes, we removed the eyes and subjected them to histopathological examination. We detected apoptotic cells by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate digoxigenin nick end labeling (TUNEL) assay, which stains the 3′-OH ends of fragmented DNA. We used electron microscopy to detect the apoptotic cells morphologically. • Results: RPE cells were selectively damaged immediately after ornithine administration. TUNEL-positive photoreceptor cells appeared exclusively in the photoreceptor cell layer 12 h after ornithine administration. The number of TUNEL-positive cells increased throughout the 2 days following the injection, then decreased markedly. TUNEL-positive cells remained until 28 days, when the photoreceptor cells had disappeared. The ganglion cell layer, inner nuclear layer and damaged RPE cells were negative for TUNEL staining during all stages. The electron microscopic study also revealed the pyknotic nuclei of apoptotic photoreceptor cells. • Conclusion: An intravitreal injection of ornithine caused primary damage to the RPE, and subsequently some of the photoreceptor cells revealed apoptosis by TUNEL assay. These findings suggest the dysfunction of the RPE causes photoreceptor cell death according to the intrinsic program of an apoptotic mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004170050066
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Time-course expression of vascular endothelial growth factor as related to the development of the retinochoroidal vasculature in rats (1998)
    Springer
    Experimental brain research 118 (1998), S. 155-160 
    Details
    ISSN: 1432-1106
    Keywords: Key words Retinochoroidal vasculature ; Retinal pigment epithelium ; Vascular endothelial growth factor ; In situ hybridization ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Growth factors involved in angiogenesis are critical to both the normal and pathological vascular development in the retina and choroid. In the present experiment, the relationship between the vascular endothelial growth factor (VEGF) expression and the retinochoroidal vasculogenesis in Sprague-Dawley rats was investigated using in situ hybridization and immunohistochemistry. It was found that VEGF was produced mainly by astrocytes and Müller cells in the neural retina, and this was correlated temporally and spatially with the retinal vasculogenesis. In addition, it was observed that, although the VEGF expression in the retinal pigment epithelium (RPE) decreased with increasing age, it persisted from the embryonic stage to adulthood. These findings indicate that the VEGF expression in RPE may play a role in the development of the choroidal vessels as well as in the maintenance of the normal structure and permeability of the choriocapillaris in adults.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050267
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Immunolocalization of transforming growth factor β during wound repair in rat retina after laser photocoagulation (1997)
    Springer
    Graefe's archive for clinical and experimental ophthalmology 236 (1997), S. 41-46 
    Details
    ISSN: 1435-702X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract • Background: Scatter photocoagulation induces regression of retinal neovascularization, but the mechanism of its therapeutic effect is incompletely understood. To elucidate the mechanism of therapeutic effect of photocoagulation is the main focus of our research. We have already demonstrated basic fibroblast growth factor (bFGF) immunolocalization during retinal wound repair following laser photocoagulation. Transforming growth factor beta (TGF β) reportedly inhibits endothelial cell growth and bFGF-induced cell proliferation in vitro. In the present study, we evaluated the immunohistochemical localization of TGF-β1 and -β2 during wound repair in the rat retina following laser photocoagulation. • Methods: Krypton laser photocoagulation was performed on the eyes of pigmented rats. The eyes were then enucleated on day 1, 3, 7, 14, 28 or 56 following the photocoagulation and enrolled into the analysis of immunohistochemical localization of TGF-β1 and -β2. • Results: Immunoreactivity for TGF-β1 and -β2 was present in the ganglion cell layer and photoreceptor outer segments of the normal adult rat retina. The cytoplasm of RPE cells at the photocoagulated lesion showed intense TGF-β1 and -β2 immunoreactivity on day 3 after laser photocoagulation. Macrophages that migrated into the lesion lacked positive staining for TGF-β1 and -β2. TGF-β immunoreactivity in RPE cells continued to be upregulated for more than 1 month compared with that in normal RPE cells. Controls did not exhibit any positive staining. • Conclusion: An elevated expression of TGF-β immunoreactivity for a longer period of time than bFGF was observed in RPE cells at the photocoagulated lesion in vivo. In the late phase of retinal wound repair, TGF-β may inhibit cell proliferation induced by mitogens, introduce an end stage of cellular events, and induce extracellular matrix induction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004170050040
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Vascular endothelial growth factor expression in choroidal neovascularization in rats (1997)
    Springer
    Graefe's archive for clinical and experimental ophthalmology 235 (1997), S. 313-319 
    Details
    ISSN: 1435-702X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: The pathogenesis of choroidal neovascularization is largely unknown. We investigated vascular endothelial growth factor (VEGF) expression in laser-induced choroidal neovascularization (CNV) in rats. Methods: Intense krypton laser photocoagulation was applied to the posterior poles of the eyes of pigmented rats to induce CNV, which was confirmed by fluorescein angiography and histopathology. The eyeballs were enucleated 1, 3, 7, 14 and 28 days after laser photocoagulation. Cryostat sections were prepared for immunofluorescence staining using anti-VEGF and macrophage marker (ED1) antibodies. The posterior segments of eyeballs pooled from photocoagulated and control rats were submitted for immunoprecipitation and immunoblotting by the anti-VEGF antibody, and reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of VEGF mRNA. Results: Very weak immunoreactivity for anti-VEGF antibody was found in the ganglion cell layer, inner nuclear layer, and retinal pigment epithelium (RPE) in the normal retina. In the development of CNV, strong positive staining for anti-VEGF antibody was found in photocoagulated areas in the subretinal space and choroid. Double immunofluorescence staining showed that many cells in lasered lesions were positive both for anti-VEGF and macrophage marker ED1 antibody staining in the early stage of this model. Immunoblots showed a positive band for the VEGF molecule in treated but not control animals. RT-PCR results demonstrated upregulation of VEGF transcripts in the CNV model compared with normal animals. Conclusions: Our findings showed the upregulation of VEGF expression in experimentally induced CNV, where it may be involved in promoting choroidal angiogenesis. Macrophages may be one of the main sources of VEGF in the early stage of the disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01739641
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Immunolocalization of basic fibroblast growth factor during wound repair in rat retina after laser photocoagulation (1996)
    Springer
    Graefe's archive for clinical and experimental ophthalmology 234 (1996), S. 695-702 
    Details
    ISSN: 1435-702X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract •Background: Basic fibroblast growth factor (bFGF) stimulates the mitogenesis of various cells and plays a key role in wound repair. We studied the immunohistochemical localization of bFGF during wound repair in the rat retina after laser photocoagulation. • Methods: Krypton laser photocoagulation was performed on the eyes of pigmented rats. The eyes were enucleated on days 1, 3, 7, 14 and 28 after the photocoagulation, and the immunohistochemical localization of bFGF was assessed. Two different monoclonal antibodies and one polyclonal antibody against bFGF as first antibodies were used. • Results: Marked immunoreactivity for bFGF was found in the ganglion cell layer, and weak immunoreactivity for bFGF was found in the retinal pigment epithelial (RPE) cells of the normal adult rat retina. On day 3 after laser photocoagulation, the nuclei and cytoplasm of proliferating RPE cells at the center of the photocoagulated lesion showed intense bFGF immunoreactivity. The nuclei of RPE cells around the lesion showed intense bFGF immunoreactivity. Macrophages that migrated into the lesion showed positive staining for bFGF. These immunoreactivity decreased with time. Controls (0.05 M Tris-HCl buffer, normal serum, or these same antibodies preabsorbed with bFGF) did not show positive staining. • Conclusion: The finding of an elevated expression of bFGF immunoreactivity in the photocoagulated lesion suggests that bFGF may play a role in wound repair in the rat retina after laser photocoagulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00292356
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A Rabbit Model of Proliferative Vitreoretinopathy Induced by Injection of Astrocytic Cultures (1999)
    Springer
    Cellular and molecular neurobiology 19 (1999), S. 759-773 
    Details
    ISSN: 1573-6830
    Keywords: proliferative vitreoretinopathy ; rabbit ; astrocytic culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1.The objective of this study was to decipher whether proliferation of astrocytes and invasion of astrocytic processes into the retina could contribute to retinal detachment in a rabbit model. 2.Cultures of astrocytes were injected intravitreally into the eyes of albino rabbits. 3.Two weeks after injection, proliferation of astrocytes on the retinal surfaces was observed. Vascular endothelial growth factor (VEGF) and proliferative cell nuclear antigen (PCNA) were found by immunohistochemistry to be expressed in the center of the astrocytic growth. 4.Using the same immunohistochemical technique to visualize glial fibrillary acidic protein (GFAP), a marker for astrocytes, processes of astrocytes in the growth were observed to penetrate into the host retina. 5.Retinal detachment was then confirmed by ultrasound, histologically, and grossly 2 weeks after injection of astrocytes. 6.Histochemistry on esterase indicated chloroesterase positive cells inside the growth. The secretion of this form of esterase might soften the vitreous and enhanced retinal detachment. 7.Six weeks after injection, VEGF and PCNA decreased in the astrocytic growth but astrocytic processes still attached onto and penetrated the host retina. 8.This study suggests that astrocytes could be a major factor in inducing retinal detachment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006957123672
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...