Objective To establish an allogenic intraocular melanoma model and observe its pathological features.Methods Thirty-six kunming mice were devided randomly into 3 groups with 12 ones in each, and allogeneic melanoma cells B16F10(C57BL16) were inoculated into the anterior chamber (AC), vitreous cavity (VC) of right eyes and under the skin (subcutaneous, SC) of the back of right feet of each grup respectively. The incidence of tumor occurance, time of breaking through the eyeball and other general pathologic features of the tumor were observed by slip-lamp biomicroscopy and operating microscopy for continuous 32 days, and the results were statistically analyzed. Pathological examination was given for tumors at last.Results The incidence of tumor occurance in both AC (12/1 2 eyes) and VC group (11/11 eyes) was higher than that in SC group (2/12 feet)（χ2=17.143, P＝0 .000；χ2=16.218, P=0.000）. The time of eyeball diabrosis was 11-13 days in AC group and 13-32 days in VC group, and there was significant difference between these two groups (Log Rank=18.22, P=0.000). The intraocular melanomas could grow progressively, but reduced and fell off when they broke through eyeball and grew in or bit for a period. The average diameter of the tumor after 32 days after inoculation was (2.27±1.97) mm in AC group，(3.82±1.85) mm in VC group and (0.94±2.27) mm in SC group. There was significant difference between VC and SC group (t=3.322，P=0.003). In pathohistological examination, tumor tissue necrosis could be observed at the center of the subcutaneous melanomas but not in intraocular melanomas.Conclusions Allogeneic intraocular melanoma model is successfully established which is convenient, repeatable, and helpful to studying the mechanism of genesis and development of this tumor. (Chin J Ocul Fundus Dis，2003，19：333-404)
Objective To determine whether the vitreous cavity and the subretinal space of different species animals support the induction of immune deviation to soluble antigen and to observe its maintenance time. Methods Bovine serum albumin(BSA)was used as a soluble antigen and inoculated into the anterior chamber(AC),the vitreous cavity(VC)and subretinal space of different animals(rat,rabbit and monkey)respectively.Recipient animals were immunized with BSA and complete Freundrsquo;sadjuvant. Delayed-type hypersensitivity(DTH)was assessed by skin challenge.The maintenance time of deviant immune response was evaluated in the fixed time interval. Results All the animals receiving intraocular antigen inoculation did not display DTH reaction.The maintenance time of immune deviation after inoculation of antigen in different sites is (1)anterior chamber:70 days in rat,90 days in rabbit,320 days in monkey;(2)vitreous cavity:100 days in rat,１50 days in rabbit,360 days in monkey;(3)subretinal space:50 days in rat,70 days in rabbit,300 days in monkey. Conclusions The maintenance time of immune deviation varied with different species of animals and different intraocular compartment.The evolution of organisms is synchronous with that of immune system. (Chin J Ocul Fundus Dis, 1999, 15: 170-173)
Objective To examine the influence of retinal pigment epithelium(RPE) cells on antigen-specific activatedlymphocytes in vitro,and to explore the role of RPE cells in the immune privilege of the eye. Methods Co-culture systems of RPE cells with antigen-specific T lymphocyte lines and resting T lymphocytes were established in vitro．Induction of apoptosis was detected by genomic DNA electrophoresis,DNA in situ end-labelling and flow cytometry. Results RPE cells induced apoptosis in antigen-specific activated T lymphocytes. 24 hours after culture,the signs of apoptosis appeared in lymphocytes co-incubated with RPE cells．As time of co-culture went on,the number of apoptosic cells increased．Quantitative analysis of apoptosic cells showed that apoptosic cells accounted for 5.95% after 24 hours, 9.38% after 48 hours,and 17.95% after 72 hours．In contrast,RPE cells induced few apoptosis in resting T lymphocytes. Conclusions These results suggest that RPE cells possess the ability to induce the apoptosis of invading lymphocytes. This phenomenon serves as a restrain mechanism of immune response and may be of vital importance in the maintenance of immune privilege in posterior segment of eye and in the protection of eye from the damage of immunogenic inflammation. (Chin J Ocul Fundus Dis, 1999, 15: 241-244)
ObjectiveTo investigate the effect of pharmacologic delay with pioglitazone, a peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, on extended perforator flap survival in a rat model. MethodsSeventy male Sprague Dawley rats, weighing 250-300 g, were randomly divided into control group (n=35) and experimental group (n=35). A three-territory flap was made, including two choke zones. Pioglitazone was dissolved in 1.5 mL saline. Oral doses of pioglitazone[10 mg/(kg·d)] was given by gavaged for 5 days in the experimental group, while the same volume of saline was given in the control group at same time point. After 7 days, the flap survival area was measured and angiographic diagnosis was made. The tissue samples were harvested from choke zone Ⅱ for histological study and vascular endothelial growth factor (VEGF) expression detection by immunohistochemical staining. The content of nitric oxide (NO) in choke zones I and Ⅱ was measured at immediate, 1, 3, 5, and 7 days after operation. ResultsThe flap general change of 2 groups was similar. Varying degrees of necrosis occurred with the extension of time in 2 groups. At 7 days after operation, the flap survival rate was 87.73%±3.25% in the experimental group and 76.07%±2.92% in the control group, showing a significant difference (t=-10.338, P=0.000). The number of true anastomosis in choke zones I and Ⅱ was 5.40±1.14 and 3.00±0.71 in the experimental group, and was 3.20±0.84 and 0.80±0.84 in the control group respectively, showing significant differences between the 2 groups (t=-3.479, P=0.008;t=-4.491, P=0.002). The microvessel density and the expression of VEGF in choke zone Ⅱ of experimental group were (33.16±7.73)/mm2 and 4 368.80±458.23, respectively, which were significantly higher than those of control group[(23.29±5.91)/mm2 and 2 241.24±554.43] (t=5.073, P=0.000;t=-14.789, P=0.000). The content of NO in the experimental group were significantly higher than those in the control group at other time points (P<0.05) except for at immediate after operation. ConclusionPharmacologic delay with pioglitazone can improve extended perforator flap viability through increasing ischemia-induced angiogenesis and choke vessels vasodilation in rat models.