ABSTRACT
The effects of the balance changes of pigment epithelium growth factor (PEDF) and vascular endothelial growth factor (VEGF) in whole-body and retinal tissue on rats with oxygen-induced retinopathy were investigated. Forty-eight neonatal SD rats at the age of 7 days were randomly divided into 4 groups. The neonatal rats in experimental groups were exposed to 75% to 80% oxygen for 5 days and then to normal air, and those in control groups were kept feeding in normal air. At the age of 17 and 22 days, all the neonatal rats received retina angiography with FITC-dextran and the pathological changes of retinal vessels and perfusion were observed. HE staining of the tissue section and the number counting of endothelial cells extending beyond the inner limiting membrane were performed to evaluate the endothelial proliferation. Immunohistochemistry was applied to detect the expression of PEDF and VEGF in retinal tissue, and ELISA to detect their expression in serum. A hypoxic-ischemic proliferation of retina and more endothelial cells extending beyond the inner limiting membrane were found in the neonatal rats in both experimental groups of 17-day old and 22-day old as compared with those in control group with the difference being statistically significant (P<0.01). VEGF staining of the rats in the 17-day old experimental group was significantly stronger, with an increasing positive rate, than that of the rats in the 17-day old control group (P<0.01). PEDF staining of the rats of 22 days old was weaker than that of the rats of 17 days old in the experimental groups (P<0.01). There was no significant difference in serum VEGF concentration among all groups (P>0.05). The serum PEDF concentration in the rats of 17 days old in experimental group was decreased significantly as compared with that in the rats of 17 days old in control group (P<0.01), and in experimental groups, the serum PEDF concentration of the rats of 22 days old was increased as compared with that of the rats of 17 days old (P<0.01). In conclusion, the obviously decreased serum PEDF concentration and the abnormal enhanced expression of VEGF density in local retinal tissue broke down the balance of PEDF/VEGF in whole-body or local tissues, which might play an important role in retinal vascular proliferation.
Subject(s)
Animals , Rats , Eye Proteins , Blood , Metabolism , Nerve Growth Factors , Blood , Metabolism , Oxygen , Rats, Sprague-Dawley , Retina , Metabolism , Retinal Diseases , Metabolism , Serpins , Blood , Metabolism , Time and Motion Studies , Vascular Endothelial Growth Factor A , Blood , MetabolismABSTRACT
The effects of the balance changes of pigment epithelium growth factor (PEDF) and vascular endothelial growth factor (VEGF) in whole-body and retinal tissue on rats with oxygen-induced retinopathy were investigated. Forty-eight neonatal SD rats at the age of 7 days were randomly divided into 4 groups. The neonatal rats in experimental groups were exposed to 75% to 80% oxygen for 5 days and then to normal air, and those in control groups were kept feeding in normal air. At the age of 17 and 22 days, all the neonatal rats received retina angiography with FITC-dextran and the pathological changes of retinal vessels and perfusion were observed. HE staining of the tissue section and the number counting of endothelial cells extending beyond the inner limiting membrane were performed to evaluate the endothelial proliferation. Immunohistochemistry was applied to detect the expression of PEDF and VEGF in retinal tissue, and ELISA to detect their expression in serum. A hypoxic-ischemic proliferation of retina and more endothelial cells extending beyond the inner limiting membrane were found in the neonatal rats in both experimental groups of 17-day old and 22-day old as compared with those in control group with the difference being statistically significant (P0.05). The serum PEDF concentration in the rats of 17 days old in experimental group was decreased significantly as compared with that in the rats of 17 days old in control group (P<0.01), and in experimental groups, the serum PEDF concentration of the rats of 22 days old was increased as compared with that of the rats of 17 days old (P<0.01). In conclusion, the obviously decreased serum PEDF concentration and the abnormal enhanced expression of VEGF density in local retinal tissue broke down the balance of PEDF/VEGF in whole-body or local tissues, which might play an important role in retinal vascular proliferation.
ABSTRACT
Background Choroidal neovascularization (CNV) is a serious complication of many fundus diseases.A variety of factors are associated with CNV.Research showed that recombinant human endostatin ( rhendostatin ) can arrest the vascular endothelial growth factor (VEGF) pathway and inhibit the proliferation of endothelial cells and angiogenesis.Objective This study was to observe the inhibition of rh-endostatin on experimental CNV.Methods The CNV animal models were created by Argon laser with the wavelength 532 nm to irradiate the inferior retina away optical disc 1-2 DD for 25 spots in 32 eyes of 16 chinchilla rabbits.The laser parameters were as follows:power 800 mW,spot diameter 75 μm and time shutter 50 ms.The models were then divided into model control group and rh-endostatin group.Rh-endostatin was intravitreously injected via scleral incision in 16 eyes of 8 model rabbits at 1 week after photocoagulation.Fundus fluorescein angiography (FFA) and optical coherence topography(OCT) were performed at 1,2,4 weeks after photocoagulation respectively.The eyeballs were enucleated and the retinal sections were prepared for the histopathologieal examination,and the contents of VEGF and pigment epithelial derived factor(PEDF) in rabbit vitreous,and blood serum were detected by ELISA at 2,4 weeks after photocoagulation.Results Retinal edema and exudes were seen in 1 week and scarring in 4 weeks after photocoagulation.In rh-endostatin injection group,the hyperfluorescence masses were seen in the background phase and early arterial phase in 42％ (84/200) of spots in the first week.The fluorescence leakage was decreased in the rh-endostatin injection group compared with control group in the second week and ceased at the third week on the FFA after injection.Variety forms of hyperreflective zones were found below the retinal pigment epithelium on the seventh day after photocoagulation.But the partial vessel occlusion and fibroplasias were identified in the rh-endostatin injection group in the third week by the OCT.The histopathological examination showed that the morphological abnormality was mild in the rh-endostatin injection group in comparison with model group.The serum PEDF concentration was significantly elevated but the VEGF/PEDF values in vitreous and serum were declined in rhendostatin injection group compared with model group (P ＜ 0.0 1 ).Conclusions Argon laser photocoagulation could induce the experimental CNV in chinchilla rabbit.Intravitreous injection of rh-endostar can effectively inhibit laser-induced CNV in rabbit.
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Background Conventional chemical method to fix the entire eyeball results in the edema of retinal nerve fiber layer and therefore influent the evaluation of tissue structure.Research showed that microwave irradiation can avoid this phenomenon. Objective This study was to investigate the appropriate energy and time duration of microwave irradiation for fixation of rabbit eyes specimen and compare the influence of different fixation methods on retinal structure. Methods Twenty-two New Zealand white rabbits were sacrificed by using venous air embolism.The eyeballs were enucleated from the rabbits and immersed in chemical reagents with glacial acetic acid,methyl aldehyde and chloroform for 2 days as the control group.The eyeballs were immersed in 400 ml physiological balance solution immediately,and then were fixed by microwave irradiation for 80,160,240 and 320 seconds under the lower power as the microwave irradiation groups.In the microwave irradiation+chemical fixation group,the specimens were immersed in chemical reagents for 1-2 hours after the microwave radiation.The morphology of retinal structure was examined and area of retinal detachment was calculated by hemotoxylin and eosin staining under the light microscope. Results A better fixation effect was obtained in the retinal section of microwave radiation for 240 seconds in comparison with that of the traditional chemical reagent fixation method for 2 days.The retina detachment ratio was 16.3%±11.5% for simple microwave method,50.0%±24.5% for chemical method,and 6.7%±7.8% for microwave+chemical method.showing a significant difference among 3 groups(F=32.43,P=0.000).Retinal staining was clear and retinal structure was almost normal in the specimens of microwave+chemical fixation group with 200-240 seeonds microwave irradiation and 1-2 hours chemical fixation. Conclusion Microwave irradiation method is a more ideal way for the fixation of retina because of taking short duration,lower toxicity and better staining.The combination of microwave radiation and chemical reagents can acquire an excellent quality of retinal section.
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AIM: To describe the prevalence and causes of low vision and blindness in a population within Sichuan province in southwestern China.METHODS: A stratified, multi-phased and cluster probability sampling design was employed to enumerate 125 641 participants from 40 351 households within 38 counties/cities. Participants underwent a comprehensive eye examination, including standardized visual acuity (VA) tests using logarithm of the minimum angle resolution charts. Prevalence was age- and gender-standardized to the 2000 China Census.RESULTS: Population-weighted prevalence of blindness was 0.77% (95% CI: 0.72- 0.82, n=966) and low vision was 1.22% (95% CI: 1.14-1.27, n=1 513). Overall, the prevalence of visual disability was 1.40% in the urban population, and 2.22% in the rural population (P<0.01). Cataract was the leading cause of visual disability (55.7%, n=1 381), and was of similar frequency in both urban and rural populations. Retinal disease was the second leading cause (9.7%, n=236), but was more common in urban than rural participants (34.3% vs 2.7%, P<0.01). Corneal disease accounted for 6.5% (n=161) of cases of visual disability, and was more common in the rural population (7.2% vs 3.9%, P=0.006). CONCLUSION: We estimate that 1.72 million people suffer from visual disability within Sichuan province, of which 525 000 are blind, the focus of blindness prevention should be in rural area.
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<p><b>OBJECTIVE</b>To identify the mutations in the gap junction protein alpha3/alpha8 gene (GJA3 or GJA8) in the Chinese family with autosomal dominant congenital cataract (ADCC).</p><p><b>METHODS</b>All subjects(5 family members and 100 unrelated control individuals)were undergone comprehensive ophthalmic examination, and genomic DNA was extracted from peripheral blood (5 mL). The exons and flanking introns of GJA3/GJA8 genes were amplified by polymerase chain reaction (PCR). Purified PCR products were then sequenced directly for screening disease-causing mutations.</p><p><b>RESULTS</b>Upon bidirectional sequence analysis, a G-->A transition at nucleotide 138 (c.138G>A)in exon 2 of GJA8 was found, resulting in synonymous mutation of glycine (GGG) to glycine (GGA). An additional G-->T transvertion at nucleotide 139 (c.139G>T) in exon 2 of GJA8, resulting in a missense mutation of asparagines (GAU) to tyrosine (UAU) at codon 47 (D47Y). These two alterations were not seen in all unaffected members and 100 unrelated control individuals. Bioinformatic analyses also showed that a highly conserved region was located at Asp47. Meanwhile no sequence variations for GJA3 were detected from the 3 affected members.</p><p><b>CONCLUSION</b>A novel disease-causing mutation (D47Y) of GJA8 gene in a Chinese family with ADCC is reported.</p>
Subject(s)
Child, Preschool , Female , Humans , Male , Amino Acid Sequence , Asian People , Genetics , Base Sequence , Case-Control Studies , Cataract , Genetics , Connexins , Chemistry , Genetics , Conserved Sequence , Exons , Genetics , Eye Proteins , Chemistry , Genetics , Family , Genes, Dominant , Genetics , Molecular Sequence Data , Mutation , PedigreeABSTRACT
AIM: To explore the fundus fluorescein angiographic characteristics and relevant clinical significance of age-related macular degeneration(AMD).METHODS: Fundus fluorescein angiography (FFA) was performed on 149 eyes of 112 patients using Nikon NF-505 fundus camera.RESULTS: Out of 149 eyes, 90 eyes were atrophic AMD (60.4%), 59 eyes were exudative AMD (39.6%) which were further divided, according to the composition and location of lesion, into subfoveal choroidal neovasculari-zation (CNV)(7 eyes of classic type, 26 eyes of occult type, 9 eyes with disciform cicatrices, juxtafoveal CNV(2 eyes of classic type, 12 eyes of occult type), and extrafoveal CNV(3 eyes of occult type).CONCLUSION: FFA can show CNV of AMD patients and its quality and location, which is helpful to guide the treatment and evaluate the prognosis.