[Effect of Lycium barbarum polysaccharides on the retinal ultrastructure of streptozocin-induced diabetic rats].

OBJECTIVE: To study the retinal ultrastructure of streptozocin (STZ)-induced diabetic rats and the intervention effect of Lycium Barbarum Polysaccharides (LBP). METHODS: The STZ-induced diabetic SD rat model was established. LBP was given to those in the treatment group by gastrogavage. Changes of body weight, blood glucose, and retinal ultrastructure at 24-week were observed. RESULTS: Early retinal changes covered mitochondrion changes, cell degeneration and apoptosis of retinal neurons and neuroglia cells in the diabetic rats. No change of body weight or blood glucose was observed between the LBP group and the diabetic model group (P > 0.05). The ultrastructural changes were obviously relieved by LBP, and limited to the inner nuclear layer. CONCLUSIONS: LBP could obviously relieve pathological changes of mitochondrion, hinder neural cell apoptosis. Its effect might not be achieved by lowering blood glucose. It was expected to be used in preventing and treating early diabetic retinal neuropathy.

[Protective effect of haliotidis on the oxidative damage in the human lens epithelial cells].

OBJECTIVE: To study the influence of haliotidis extractive on the oxidative damage in the human lens epithelial cells cultured in vitro. METHODS: Experimental study. Cultured human lens epithelial cells in vitro were intervened with hydrogen peroxide caused oxidative damage model, at the same time added different concentrations of concha haliotidis extractive. With control experiment research cells were divided into the blank control group, positive control group hydrogen peroxide group and hydrogen peroxide and different concentrations of concha haliotidis group, and on the first, third, fifth day the activity of Cultured human lens epithelial cells were detected with Cell Counting Kit-8 (CCK-8) , cellular proliferation and morphological changes were observed with interred phase contrast microscope, and then on the third day chemical colorimetric were used to detect the homogenates superoxide dismutase(SOD), glutathione(GSH) and malondialdehyde (MDA) level. RESULTS: (1) At different time points there were variations between the activity of HLEC in each experimental group, Among each experimental group HLEC OD value of the cell vitality at 1 d, 3 d, 5 d , respectively were blank control group: 0.88, 1.28, 1.32; Positive control group: 0.73, 1.02, 1.06; 0.001% concha haliotis extract group: 0.73, 1.03, 1.06; 0.01% concha haliotis extract group: 0.76, 1.10, 1.13; 0.1% concha haliotis extract group: 0.79, 1.22, 1.21; 0.3% concha haliotis extract group: 0.79, 1.21, 1.21; the difference between groups was statistically significant (P < 0.05) (1 d, F = 23 922.42, P < 0.05;3 d, F = 120 605.86, P < 0.05; 5 d, F = 150 939.45, P < 0.05). H2O2 made the vitality of the cells reduce, concha haliotidis enhance its vitality, and in a certain range of time and concentrations there was dependence, with which the third day and 0.1% was the best. (2) After adding H2O2, the SOD and GSH level of HLEC reduced,(SOD 158.05 U/mgprot,GSH 15.05 mg/gprot) but MDA increased to 18.11 nmol/mgprot, concha haliotidis groups made the increase of antioxidant level(SOD 188.64 U/mgprot,GSH 21.05 mg/1000 mgprot)and the decrease of lipid peroxidation in oxidative damaged HLECs(MDA 14.16 nmol/mgprot), change had a statistical significance(P < 0.05) (SOD: F = 983.04, P < 0.05; GSH: F = 444.44, P < 0.05; MDA: F = 830.52, P < 0.05). (3)The chromatin of the positive control group concentrated and aggregated obviously, the aggregation of chromatin in concha haliotidis group lightened. CONCLUSION: The concha haliotidis can protect the cultured human lens epithelial cells in vitro which are oxidative injured, increased intracellular antioxidant levels, reduce the generation of hazardous products.

[Effect of Optimized Fertilization and Biochar Application on Phosphorus Loss in Purple Soil Sloping Farmland].

Phosphorus is an essential nutrient for crop growth, but the input of excess phosphorus is a significant cause of eutrophication. This study explored the relationship between fertilization methods and phosphorus loss in actual production, providing a theoretical basis for scientific fertilization and rational reduction of fertilizer application. In the experiment, a wild-type OD flow plot was used to monitor the occurrence of multiple rainfall runoff and sediment yield in purple soil sloping farmland in 2017-2018. Four different schemes of non-fertilizer treatment, conventional fertilization treatment, optimized fertilization treatment, and reduced fertilization combined with biochar were studied. The effects of soil flow, surface runoff, and sediment phosphorus loss on purple soil sloping farmland were analyzed. The results showed that:①The total yield of each treatment was optimized (20737.23 L) > conventional (18513.17 L) > CK (18134.58 L) > biochar (13594.85 L), and the total sediment yield of each treatment was CK (1998 kg·hm-2) > biochar (1884 kg·hm-2) > optimized (1681 kg·hm-2) > conventional (910 kg·hm-2). The middle stream of soil is the main type of runoff in the rainy season, accounting for 60.14%-87.34% of the total output flow. The total amount of sediment produced by each treatment was not significantly different from that of the conventional treatment (P>0.05). ②The flux of total phosphorus loss in each treatment was characterized by sediment > surface runoff > soil middle flow. Phosphorus lost through the middle stream of soil is the least, accounting for only 2.63%-12.91% of the flux of total phosphorus loss, while the flux of sediment loss of phosphorus can reach 63.74%-78.74%, and thus is the main output route of soil phosphorus loss. ③The application of biochar can effectively reduce the abortion flow in the soil of purple soil sloping land, and the loss flux of orthophosphate in the middle stream, which are 49.94% and 56.45% lower than the conventional treatment, respectively. However, the interception effect on surface runoff is not good, and there is no significant influence on the flux loss of particulate phosphorus. At the same time, the flux of total phosphorus in surface runoff and sediment is significantly increased by 73.28% and 123.53%, respectively, compared with conventional treatment (P<0.05). Therefore, to control the loss of phosphorus in purple soil sloping farmland in southwest China, we should focus on reducing the occurrence of soil sediment loss. Bio-carbon should be further optimized in the practical application of agricultural production with the phosphorus fertilizer input ratio.

[Effect of cinobufagin on the expressions of bcl-2 mRNA and bax mRNA and the proliferation of lens epithelial cells].

OBJECTIVE: To investigate the effect of cinobufagin on the proliferation of lens epithelial cells (LECs) and the bcl-2 and bax mRNA expressions of rabbits. METHODS: Cultured LECs were treated for 72 h with cinobufagin of different concentrations, the end titer was 0.1 mg/L for low, 0.2 mg/L for moderate and 0.3 mg/L for high concentration, respectively. The inhibitory rate of cinobufagin on LECs' proliferation was detected using MTT method; the mRNA expressions of bcl-2 and bax genes in LECs were examined using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Proliferation of LECs was inhibited significantly by cinobufagin in a concentration dependent manner, the inhibitory rate was 24.65%, 30.13% and 36.98% respectively for low, moderate and high concentration. With the drug concentration increasing, the mRNA expression levels of the pro-apoptotic bax were increased, whereas those of the anti-apoptotic bcl-2 decreased. CONCLUSION: Cinobufagin can remarkably inhibit the proliferation and induce the apoptosis of LECs in vitro, it might be taken as one of the drugs for the prevention and treatment of after-cataract.

[Protective effects of melatonin on cultural human retinal pigment epithelial cells against oxidative damage in vitro].

OBJECTIVE: To investigate the protective effects of melatonin on the retinal pigment epithelium (RPE) against oxidative damage induced by hydrogen dioxide (H2O2) and its mechanism. METHODS: The RPE cells were seeded and divided into normal control group, oxidative damage group and the treatment group (treated with melatonin at the concentration of 1 x 10(-7) mol/L, 1 x 10(-6) mol/L, 1 x 10(-5) mol/L and 1 x 10(-4) mol/L). The model of oxidative damage on the RPE cells was established by culturing the RPE cells with H2O2 at the concentration of 600 micromol/L for 1 hour in vitro. The cell viability of RPE cells was detected by the methyl thiazolyl tetrazolium (MTT) method. The degree of oxidative damage was evaluated by detecting the superoxide dismutase (SOD) and maleic dialdehyde (MDA). Apoptosis was detected qualitatively using the DNA Ladders electrophoretic method, and quantitatively using the Annexin V-FITC/PI double staining flow cytometry. RESULTS: Compared with normal control group, the oxidative damage group had low cell viability, low SOD and high MDA contents, and high apoptosis rate (t = 2.25, 39.50, 68.42; P < 0.05). Compared with oxidative damage group, the treatment group had high cell viability, high SOD and low MDA contents, and low apoptosis rate (P < 0.05). CONCLUSIONS: Melatonin has a protective effect on the RPE against oxidative damage induced by H2O2. The mechanism may involve in reinforcing the cell viability, strengthening the activity of antioxidase, and reducing the apoptosis.

Culture in vitro modulation of human leukocyte antigen molecules and costimulatory molecules on human retinal pigment epithelium.

PURPOSE: To determine the potential of culture in vitro to alter the human leukocyte antigen (HLA) molecules and costimulatory molecules on human retinal pigment epithelium (RPE). METHODS: Pure RPE were isolated and cultured. Two sets of RPE (normal and activated) were used. Activated RPE were obtained by incubating primary cultures of RPE with recombinant human interferon-gamma. The expression of HLA molecules and costimulatory molecules on human RPE at different passages after culture in vitro were analyzed quantitatively by flow cytometry. RESULTS: In the process of routine culture on culture flask, the duration of culture in vitro was significantly correlated with the expression of HLA-ABC molecules on the normal RPE and the activated RPE (r = -0.893, p < 0.001 and r = -0.964, p < 0.001 respectively), HLA-DR molecule on the activated RPE (r = -0.901, p < 0.001) and intercellular adhesion molecule-1 on the normal RPE (r = 0.961, p < 0.001). There were no correlations between the duration of culture in vitro and the expression of HLA-DR molecule on the normal RPE, intercellular adhesion molecule-1 on the activated RPE, B7-1 and B7-2 molecules on the normal RPE and the activated RPE. CONCLUSIONS: The chronic rejection is the major immunological rejection following RPE allogeneic graft. Culture in vitro modulation of HLA molecules and costimulatory molecules on RPE may increase lymphocyte infiltration and the activated RPE.

Rat model for anterior segment intraocular surgery induced blood-retinal barrier breakdown.

PURPOSE: To develop a practical rat model of blood-retinal barrier (BRB) breakdown induced by anterior segment intraocular surgery. METHODS: A 27-gauge needle attached to infusion tubing running to a bottle of balanced salt solution was inserted through the limbus into the rat anterior chamber. The pressure of the balanced salt solution was oscillated from 0 to 12 mm Hg above the atmospheric pressure for 30 times. The needle was removed and the anterior chamber was formed. Then the eye was exposed vertically to the light of the operating microscope. The contralateral eye was left untreated. The eyes were applied with ofloxacin ophthalmic solution after surgery. At several time points after surgery, the integrity of the BRB was assessed by fluorescence fundus angiography, optical coherence tomography, immunohistochemical staining for serum albumin and quantitative measurement using Evans blue as a tracer. RESULTS: The extravasation of fluorescein, the increased central retinal thickness, strong staining for albumin in the retina and substantially elevated retinal Evans blue leakage demonstrated BRB breakdown after anterior segment intraocular surgery. On the 1st day after surgery, the model group showed a statistically significant elevation in the retinal Evans blue leakage as compared to the contralateral control group and the normal control group. These increased and reached the peak on the 2nd day after surgery and decreased to the point that there was no significant difference as compared to the contralateral control group and the normal control group on the 7th day after surgery. CONCLUSIONS: This study establishes a practical rat model of BRB breakdown induced by anterior segment intraocular surgery.

[Study on the interaction of tetra-sulfonated phathalocyanine cobalt with bovine serum albumin].

The tetra-sulfonated phathalocyanine cobalt(CoPcS4)was synthesized by using 4-sulfonic phthalic acid as raw material, CoCl2 as template agent and (NH4)2 MoO4 as catalyst. CoPcS4 was demonstrated to be C4h mono-isomer by elementary analysis, IR, NMR and HLPC. Depolymerization of CoPcS4 was found in DMSO. The depolymerization increased with the pH value raising. The interaction of tetra-sulfonated phathalocyanine cobalt with bovine serum albumin (BSA) was studied by UV-Vis and fluorescence spectra The number of binding sites and binding constant were determined at equal pace of the order of magnitude 10(5) L x mol(-1). CoPcS4 binds with BSA at Site I and Site II. In conclusion, COPcS4 binds with BSA commendably and albumin plays a role of storage and transport.

Experimental circumferential canaloplasty with a new Schlemm canal microcatheter.

AIM: To present a new, simple, inexpensive Schlemm canal microcatheter for circumferential canaloplasty in a rabbit model. METHODS: A rabbit glaucoma animal model was established by intravitreal injection of triamcinolone acetonide. Circumferential canaloplasty with a new Schlemm canal microcatheter (patent license number: 201220029850.0) was performed. The Schlemm canal microcatheter was composed of microcatheter wall and lumen. The wall was made of high refractive index plastic optical fiber that could be attached to an illuminant so that the whole lighted microcatheter was visible during circumferential canaloplasty. The lumen could be attached to an injector for injection of viscoelastic during catheterization. Rabbits were divided randomly into the control, model and treatment groups. Intraocular pressure (IOP) was measured with a Tono-pen tonometer pre-operation and 3, 7, 14, 21 and 28d post-operation. Ultrasound biomicroscopy was performed to visualize the Schlemm canal microcatheter in the Schlemm canal and the sclera pool. RESULTS: The Schlemm canal microcatheter could be used to perform circumferential canaloplasty in the rabbit glaucoma animal model. IOP was lower in the treatment group than that in the model group 3, 7, 14 and 28d after operation. There were no significant differences in IOP between the control group and treatment group. The differences among the three groups were statistically significant (3d: F=41.985, P<0.001; 7d: F=65.696, P<0.001; 14d: F=114.599, P<0.001; 28d: F=55.006, P<0.001). CONCLUSION: Circumferential canaloplasty is safe and effective in control of experimental glaucoma model in rabbits.

[Synthesis and characterization of octa-carboxylic phthalocyanine aluminum and its interaction with bovine serum albumin].

Octa-carboxylic phthalocyanine aluminium (AlPc(COOH)8) was used as fluorescent probe of infrared region. The interaction of octa-carboxylic phthalocyanine aluminium (AlPc(COOH)s) and bovine serum albumin(BSA) was studied by UV/ Vis and fluorescence spectra methods. The binding constant KA and n of phthalocyanine aluminium with BSA were determined. The results were K=5. 74 X 10(5) , n= 5. 7 and K= 3. 51 X 10(5) , for these two methods respectively. The same results by using two different analytical methods were obtained. Besides, hemin chloride(HE), ibuprofen(IB) and L-tryptophan(TRP) were used as probes, and the effects of these probes on the spectra of AlPc(COOH)8 )-BSA were studied by competitive binding method. The result indicated that, by adding HE into the AlPc(COOH)8)-BSA system, obvious spectral change of the system was observed, while adding TRP and IB caused no spectral changes. The binding site of octa-carboxylic phthalocyanine aluminium on the BSA was found to be at the I site by competitive binding method.

Infliximab relieves blood retinal barrier breakdown through the p38 MAPK pathway in a diabetic rat model.

AIM: To clarify the mechanism of infliximab treatment in diabetic macular edema (DME) and to provide a new alternative therapy for DME. METHODS: Rats were randomly divided into the control group, the model group and the infliximab treatment group. A diabetic rat model was created. The concentration of TNF-α in the vitreous body was detected by ELISA. The expressions of B-Raf, p38, claudin-1 and occludin in the retina were detected by Western blot. The integrity of the blood retinal barrier (BRB) was measured using Evan's blue as a tracer. RESULTS: After three months and six months of the diabetes model, the vitreous TNF-α level in the model group was higher than that of the control group. It was also higher in treated group than that of the control group but was lower than that of the model group. The differences among the three groups were statistically significant (at 3mo, F=857.098, P<0.001; 6mo, F=1261.897, P<0.001). The retina B-Raf and p38 levels in the model group were higher than that of the control group. They were also higher in treated group than that of the control group but were lower than that of the model group. The differences among the three groups were statistically significant (B-Raf at 3mo, F=106.596, P<0.001 and at 6mo, F=200.681, P<0.001; p38 at 3mo, F=41.662, P<0.001 and at 6mo, F=67.979, P<0.001). The retina claudin-1 and occludin levels in the model group were lower than that of the control group. They were also lower in treated group than that of the control group but were higher than that of the model group. The differences among three groups were statistically significant (claudin-1 at 3mo, F=139.088, P<0.001 and at 6mo, F=128.415, P<0.001; occludin at 3mo, F=92.733, P<0.001 and at 6mo, F=104.478, P<0.001). The retinal Evans blue leakage in the model group was higher than that of the control group. It was also higher in treated group than that of the control group but was lower than that of the model group. The differences among the three groups were statistically significant (at 3mo, F=447.946, P<0.001; at 6mo, F=1610.732, P<0.001). CONCLUSION: In a diabetic rat model, infliximab may relieve TNF-α induced BRB breakdown via the B-Raf and p38 signaling pathway.

Aquaporin-1 down regulation associated with inhibiting cell viability and inducing apoptosis of human lens epithelial cells.

AIM: To investigate the role of Aquaporin-1 (AQP-1) in lens epithelial cells (LECs) and its potential target genes. AQP-1 is specifically expressed in LECs of eyes and is significant for lens homeostasis and transparency maintenance. Herein, AQP-1 expression in LECs was investigated to evaluate its influence on cell survival in association with its potential role in cataract formation. METHODS: LECs were transfected with lentivirus carrying AQP-1 small interfering RNA (siRNA). Real-time polymerase chain reaction (PCR) and Western blotting were conducted to detect AQP-1 expression in LECs from different groups. Meanwhile, cell counting kit-8 (CCK-8) assay and flow cytometry were performed to measure LEC proliferation and apoptosis, respectively. RESULTS: AQP-1 expression was significantly reduced in LECs, both at mRNA and protein levels (P<0.05), after siRNA treatment. Decreased cell viability was detected by CCK-8 assay in LECs with siRNA interference, compared to control cells (P<0.05). The apoptosis rate significantly increased in cells after siRNA interference (P<0.05). CONCLUSION: The decreased cell viability following AQP-1 down regulation is largely due to its induction of apoptosis of LECs. AQP-1 reduction might lead to changes of physiological functions in LECs, which might be associated with the occurrence and development of cataracts.

Blood pressure change during phacoemulsification and femtosecond laser-assisted cataract surgery.

AIM: To evaluate blood pressure (BP) changes during phacoemulsification (PC) and femtosecond laser (FSL)-assisted cataract surgery. METHODS: A retrospective chart review was performed for all patients who received traditional phacoemulsification surgery (PC group) and FSL-assisted cataract surgery (FS group) from July 2013 to December 2014. Totally 206 eyes from 133 patients receiving the two types of procedures were included. Patient characteristics (age, gender, and hypertension history), pre- and post-operative BPs were collected. RESULTS: The pro-operative systolic and diastolic BPs (mm Hg) were 124.89±20.48 vs 126.98±16.85, and 71.88±9.81 vs 73.56±10.03, in PC and FS groups, respectively. While the post-operative systolic and diastolic BPs (mm Hg) were 130.13±22.59 vs 134.77±17.52, and 73.41±11.62 vs 78.89±12.2, in PC and FS groups, respectively. Paired-sample t-tests showed obvious systolic and diastolic BP elevations in FS group after surgery (P=0.001 and 0.007) and no reliability in PC group (P=0.094 and 0.359). A linear regression model revealed systolic and diastolic BP elevations, which were related to longer surgical times for FS group (P=0.008 and 0.021). Age, gender, and hypertension history were not correlated with blood pressure elevation in either group. CONCLUSION: BP increases but at a limited level after FSL-assisted cataract surgery compared to traditional phacoemulsification.

[Expression and significance of transforming growth factor-beta1, matrix metalloproteinase-2 and its inhibitor in lens epithelial cells of diabetic cataract].

OBJECTIVE: To investigate the expression and significance of transforming growth factor-beta(1) (TGF-beta(1)), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in human Lens epithelial cells (LEC) of diabetic cataract. METHODS: Immunohistochemical staining was used to detect the expression of TGF-beta(1), MMP-2 and TIMP-2 in the diabetic LEC (23 cases) and the normal LEC (7 cases). RESULTS: There was significant difference of expression of MMP-2 and TGF-beta(1) between diabetic LEC and normal LEC (P < 0.01). But there was no statistic significance for TIMP-2 expression (P > 0.05). There was correlation between the expression of TGF-beta(1) and MMP-2. CONCLUSION: The imbalance induced by TGF-beta(1) between the expression of MMP-2 and TIMP-2 may play a critical role in the pathological fibrosis of anterior and posterior subcapsular during the development of diabetic cataract.

Stromal cell-derived factor 1α-stimulated mesenchymal stem cells confer enhanced protection against light-induced retinal degeneration in rats.

PURPOSE: Mesenchymal stem cells (MSCs) are currently considered to be modulators of repair in various tissues. After MSC transplant, photoreceptor rescue has been demonstrated in models of retinal degeneration. Herein, we evaluate the roles of MSCs in modulating the host reaction and photoreceptor preservation in rats suffering from light-induced retinal degeneration. METHODS: Unstimulated and stromal cell-derived factor 1α (SDF-1α)-stimulated MSCs were intravenously transplanted into light-injured rats. Their photoreceptor rescue effect was compared with untreated light-injured rats and light-injured rats received only medium injection. Ciliary neurotrophic factor (CNTF) and glial fibrillary acidic protein (GFAP) expression was identified to assess host reaction post-transplantation. Retinal localization and integration of MSCs were determined by green fluorescence protein labeling. RESULTS: MSCs were able to migrate and integrate into the host retina, and significantly inhibited retinal cell death. CNTF and GFAP were induced upregluation after MSC injection. SDF-1α stimulation elicited superior effects in both MSC migration and the inhibition of apoptosis. CNTF and GFAP expression in host retinas that received stimulated MSCs were stronger than in retinas that received unstimulated MSCs. CONCLUSIONS: Systemic administration of MSCs exerts a protective effect against light-induced retinal degeneration, and upregulates neurotrophin expression in the host retina. MSCs can be stimulated to enhance the therapeutic effect.

Mesenchymal stem cells for retinal diseases.

Retinal diseases are featured with the common result of retinal cell apoptosis that will cause irreversible vision loss. Various attempts have been made for the solution against cell death. However, few approaches turn out to be effective. With the progress in mesenchymal stem cells (MSCs) research, MSCs were considered as a promising source for cell replacement or neuroprotection in retinal disorders. MSCs have the property of self-renewal and are multipotent cells derived from various mesenchymal tissues, which were demonstrated being capable of differentiating into multilineage tissue cells. Some works were also done to differentiate MSCs into retinal cells. MSCs could be induced to express retinal cell markers under certain stimuli. Recent studies also suggest that MSCs should be an ideal source for neuroprotection via the secretion of a variety of neurotrophins. Engineered MSCs were also used as vehicles for continuous delivery of neurotrophins against retinal degeneration with encouraging results. Since there are still barriers on the differentiation of MSCs into functional retinal cells, the use of MSCs for neuroprotection in retinal diseases seems to be a more practicable approach and worthy of further investigations.

Proteome changes during bone mesenchymal stem cell differentiation into photoreceptor-like cells in vitro.

Human bone marrow stem cell (BMSC) may be directed to differentiate into multiple cell types, including adipocyte, chondrocyte, osteocyte and photoreceptor, among others. At present, little is known about the features of the BMSC and the protein control mechanism underlying their differentiation into photoreceptor-like cells. In the present study, BMSCs are induced to differentiate into photoreceptor-like cells in an in vitro model simulating the in vivo microenvironment. Up to 32 proteins are identified and differentially expressed through two-dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to establish a differential protein database for photoreceptor-like cells from BMSC-induced differentiation. Western blot analysis further confirms the expression of some of the identified proteins. The present study proposes the total protein expression and possible molecular mechanism during the differentiation of BMSCs into photoreceptor cells.

Comparison of the retinal modulation transfer function between amblyopes successfully corrected and normal subjects.

AIM: To analyze the retinal modulation transfer function between amblyopes whose visual acuity was corrected to 5.0 and normal subjects at the same age. METHODS: RM-800 used to detect contrast sensitivity was adopted to measure MTF of 96 amblyopes (96 eyes) whose visual acuity was corrected to 5.0 and 80 normal controls (80 eyes) at the same age under six interference fringes (IVA=0.06, 0.1, 0.2, 0.4, 0.6, 0.8). RESULTS: The functional values of amblyopes were significantly lower than those of normal subjects in every fringe (P<0.01), especially in medium and high frequency. CONCLUSION: For amblyopes, MTF was still abnormal after stopping the treatments.

Experimental study on the photodynamic treatment of choroidal neovasculization with nanophthalocyanine photosensitizer.

AIM: To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs). METHODS: Two types of photosensitizers, G(1)-ZnPc(COOH)(8) and G(1)-ZnPc(COOH)(8)/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (△Ψm) were conducted on HRPE and HRECs after initial uptake of the two drugs. RESULTS: Both photosensitizers demonstrated an improvement of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G(1)-ZnPc(COOH)(8)/m showed a better CNV closure effect versus G(1)-ZnPc(COOH)(8) (P<0.05). A significant difference (P<0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs (P>0.05). Both photosensitizers showed cytotoxicity on HRPE, but G(1)-ZnPc(COOH)(8)/m induced a lower cell viability. CONCLUSION: G(1)-ZnPc(COOH)(8)/m mediated PDT is better than G(1)-ZnPc(COOH)(8) in CNV closure and also have the advantage of fast metabolism leading to less side effect.

Apoptosis of lens epithelial cells induced by cinobufagin in vitro.

AIM: To investigate the in vitro effects and mechanism of action of cinobufacini on apoptosis of lens epithelial cells (LEC). METHODS: Rabbit LEC were cultured for 72 hours with cinobufacini at different concentrations(0.0 [control], 0.1, 0.2, 0.3mg/L). The inhibition ratio of cinobufacini acting on LEC was analyzed by ethyl thiazolyl tetrazolium(MTT); the changes in DNA structure, by electrophoresis, and the apoptosis rate, by flow cytometry. The mRNA expression of apoptosis-related genes bcl-2 and bax was examined using the reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: At concentrations of 0.1mg/L-0.3mg/L, cinobufacini inhibited LEC proliferation. The inhibition ratio increased as the concentration of the drug increased. The typical DNA-ladders on electrophoretic gels were observed for extracts of LEC in the treated groups. The higher the drug concentration (0.1, 0.2, and 0.3mg/L) was, the higher the apoptosis rate (20.47±0.65%, 27.14±0.95%, and 33.49±0.77%, respectively) would be. The apoptosis rates in these groups were significantly different from those of the control group (P<0.01). With the drug concentration increasing, the mRNA expression levels of the pro-apoptotic bax increased, whereas those of the anti-apoptotic bcl-2 decreased. CONCLUSION: Cinobufacini can notably induce apoptosis of LEC by decreasing the ratio of bcl-2 to baxin vitro. With its low toxicity, this medication may be effective in the prevention and treatment of posterior capsule opacification.