Effect of long-term weightlessness on retina and optic nerve in tail-suspension rats.

AIM: To evaluate the effect of long-term weightlessness on retina and optic nerve in tail-suspension (TS) rats. METHODS: A stimulated weightlessness model was established by suspending rats' tail. After 12wk, the ultrastructure and the number of optic nerve axons were observed by transmission electron microscope. The number of survival retinal ganglion cells (RGCs) was calculated by fluorescent gold retrograde labeling. Retina cells apoptosis was detected by TUNEL staining. The function of optic nerve and retina was evaluated by the visual evoked potential (VEP) and oscillatory potentials (Ops). RESULTS: The optic nerve axons were swollen and sparsely aligned, and the lamellar separation and myelin disintegration occurred after 12wk in TS rats. The density of optic nerve axons was 32.23±3.92 (vs 37.43±4.13, P=0.0145), the RGCs density was 1645±46 cells/mm(2) (vs 1867±54 cells/mm(2) P=0.0000), the incidence rate of retinal cells apoptosis was 5.38%±0.53% (vs 4.75%±0.54%, P=0.0238), the amplitude of VEP-P100 was 15.43±2.14 µV (vs 17.67±2.17 µV, P=0.0424), the latency of VEP-P100 was 69.05±5.34ms (vs 62.43±4.87ms P=0.0143) and the sum amplitude of Ops was 81.05±8.34 µV (vs 91.67±10.21 µV, P=0.0280) in TS group and the control group, respectively. CONCLUSION: Long-term weightlessness can induce the ultrastructural changes and functional depress of the optic nerve, as well as retinal cell damages in TS rats.

Effects of Foxp3 gene modified dendritic cells on mouse corneal allograft rejection.

OBJECTIVE: To investigate the effect of Foxp3 gene modified dendritic cells (Foxp3 + DC) on allogeneic T cells proliferation and to study the effect of Foxp3 + DC on corneal allograft rejection. METHODS: Lentivirus-Foxp3 was transfected into DC2.4 cells, as Foxp3 + DC cells. 42 BALB/c mice were randomly divided into: Group A (n = 6), normal group; Group B (n = 12), Group C (n = 12) and Group D (n = 12), allograft groups, were treated with normal saline, DC2.4, Foxp3 + DC by intraperitoneal injection, respectively. RESULTS: Compared with the control group, Foxp3 protein in the Foxp3 + DC cells increased significantly (P < 0.05); the expressions of CD80 and CD86 immunophenotypes of Foxp3 + DC cells decreased significantly (P < 0.05); IL-12 secretion reduced (P < 0.05), but IL-10 secretion was promoted (P < 0.05). The average transplant survival time in Group B was (14.833 ± 1.472) d, and Group C and Group D led to a statistically significant prolongation of transplant survival to (17.667 ± 1.366, 23.000 ± 2.000) d (P < 0.05) respectively. 14 d after transplantation, as compared with Group C and D, the expressions of IFN-γ in grafts markedly increased in Group B. 14 d after transplantation, as compared with Group B, the expressions of Foxp3 mRNA, IDO mRNA in grafts decreased remarkably in Group C and D (P < 0.05); as compared with Group C, the expressions of Foxp3 mRNA, IDO mRNA in grafts decreased remarkably in Group D (P < 0.05). CONCLUSION: Foxp3 + DC cells reduce the expression of costimulatory factors, reduce the secretion of IL-12, promote IL-10 production and inhibit the stimulation of alloreactive T cell proliferation response capacity. Foxp3 + DC cells play important roles in inhibiting corneal allograft immune response and prolonging graft survival time.

Correlation of in vivo and in vitro methods in measuring choroidal vascularization volumes using a subretinal injection induced choroidal neovascularization model.

BACKGROUND: In vivo quantification of choroidal neovascularization (CNV) based on noninvasive optical coherence tomography (OCT) examination and in vitro choroidal flatmount immunohistochemistry stained of CNV currently were used to evaluate the process and severity of age-related macular degeneration (AMD) both in human and animal studies. This study aimed to investigate the correlation between these two methods in murine CNV models induced by subretinal injection. METHODS: CNV was developed in 20 C57BL6/j mice by subretinal injection of adeno-associated viral delivery of a short hairpin RNA targeting sFLT-1 (AAV.shRNA.sFLT-1), as reported previously. After 4 weeks, CNV was imaged by OCT and fluorescence angiography. The scaling factors for each dimension, x, y, and z (µm/pixel) were recorded, and the corneal curvature standard was adjusted from human (7.7) to mice (1.4). The volume of each OCT image stack was calculated and then normalized by multiplying the number of voxels by the scaling factors for each dimension in Seg3D software (University of Utah Scientific Computing and Imaging Institute, available at http://www.sci.utah.edu/cibc-software/seg3d.html). Eighteen mice were prepared for choroidal flatmounts and stained by CD31. The CNV volumes were calculated using scanning laser confocal microscopy after immunohistochemistry staining. Two mice were stained by Hematoxylin and Eosin for observing the CNV morphology. RESULTS: The CNV volume calculated using OCT was, on average, 2.6 times larger than the volume calculated using the laser confocal microscopy. The correlation statistical analysis showed OCT measuring of CNV correlated significantly with the in vitro method (R 2 =0.448, P = 0.001, n = 18). The correlation coefficient for CNV quantification using OCT and confocal microscopy was 0.693 (n = 18, P = 0.001). CONCLUSIONS: There is a fair linear correlation on CNV volumes between in vivo and in vitro methods in CNV models induced by subretinal injection. The result might provide a useful evaluation of CNV both for the studies using CNV models induced by subretinal injection and human AMD studies.

Influence of N(2)O(4) on multifocal electroretinogram in winstar mice.

AIM: To record multifocal electroretinogram from different dosage of N(2)O(4) injected mice. In order to provide a foundation for further study. METHODS: Normal winstar mice which were injected by different dosage of N(2)O(4) were studied for recording multifocal electroretinogram in the same time in the evening after N(2)O(4) injection. RESULTS: The latency and amplitude density of "b" wave of each ring of multifocal electroretinogram was studied. The latency of "b" wave of each ring of multifocal electroretinogram of each group varies to each other. But the difference of the amplitude of "b" wave of multifocal electroretinogram of each ring between each group had no significance. CONCLUSION: Recording multifocal electroretinogram of N(2)O(4) injected mice will give more support for further study in related science and clinic research.

[The prevalence and its effective factors of primary angle-closure glaucoma in defined populations of rural and urban in Beijing].

OBJECTIVE: To investigate the prevalence of primary angle-closure glaucoma (PACG) of urban and rural residents in Beijing, China. A quantitative comparison was made based on the data collected from this epidemiological survey. We also identify some of the most typical risk factors associated with PACG. METHODS: Glaucomatous screening examination was applied to specific age group populations (aged 40 and older) in the defined district of Beijing and its remote rural county, from June to October, 2001. There are 4451 subjects in all, 1980 rural subjects and 2471 urban subjects, 1939 males and 2512 females. The screen and diagnostic methods used in this survey included van Herick methods and gonioscopy examination to estimate the peripheral depth of the anterior chamber, visual acuity, intraocular pressure, refraction status, stereoscopic fundus photography, and threshold-related visual field tests. Subjects regarded as suspected glaucoma and glaucoma patients are reexamined with standard glaucomatous examination. RESULTS: The response rate of rural and urban population is 79.6% (1980/2488), 87.1% (2471/2836), respectively. The prevalence of PACG (in aged 40 years or older population) resulted from this survey was 1.2% (95% CI 0.9% - 1.5%). However, the prevalence was different between urban and rural residents, 1.1% (95% CI 0.8% - 1.4%) vs. 1.6% (95% CI 1.2% - 2.0%). The prevalence of PACG in female was more than that in male, 1.7% (95% CI 1.3% - 2.1%) vs.0.8% (95% CI 0.5% - 1.1%). A drastic increase in prevalence of PACG with age increase was identified in both survey sites, however, this increase in rural subjects (aged 60-69 years group) occurred ten years earlier than those from urban subjects (aged more than 70 years group). Compared to urban residents, rural residents showed higher prevalence of unilateral low vision (39.3% vs. 20.6%) and blindness (28.6% vs. 14.7%). This survey also confirmed that, as people aging, refraction status became hyperopia, the depth of peripheral anterior chamber became narrow. In the different age groups, female and male groups, the changes of refraction status and the depth of peripheral anterior chamber paralleled the prevalence of PACG. CONCLUSIONS: The prevalence of PACG was obviously different in different groups. This could due to several factors including gender, age, change of refraction status and chamber angle as well.