Objective To observe the histological changes and apoptosis of retinal cells in pigmented rabbits treated by transpupillary thermotherapy (TTT) with different laser power. Methods Fourteen pigmented rabbits (28 eyes) were divided averagely into seven groups（control group, 50, 70, 90, 110, 130, and 150 mW group）according to different laser power of TTT. Light microscopy was performed to observe the histological changes, and TDT-mediated biotin-dUTP nick-end labeling (TUNEL) technique and flow cytometry (FCM) examination were used to detect the apoptotic cells 24 and 48 hours after photocoagulation, respectively. Results The color of retinal burn speckles changed from offwhite to white and super white with the diameter enlarged gradually as the laser power of TTT increased. The results of light microscopy revealed that compared with the control group, the retinal tissue did not change much in 50-70 mW group; in 90-130 mW group, the retinal structure was integrated, but the cone and rod cells became swollen and condensed nuclei and cytoplasmic vacuolization were seen in the inner nuclear layer. The difference of retinal structure in 50-130 mW group 24 and 48 hours after photocoagulation and control group was not significant. In 150 mW group, tumefaction and degeneration were observed in each layer of retina and the inner and outer segments of photoreceptor cells lost 24 hours after photocoagulation, and obvious necrosis and cell loss of retinal tissues were detected hours after photocoagulation. The results of TUNEL examination indicated that positive cells were found in outer nuclear layer in each photocoagulation group which increased as the laser power of TTT was enhanced; the apoptosis gradually involved the inner nuclear layer and ganglion cell layer. The results of flow cytometry (FCM) examination showed the peak of apoptotic cells in each photocoagulation group 24 hours after photocoagulation. Conclusion Under certain subthreshold photocoagulation (50-70 mW), retinal tissue of rabbits does not change much but apoptosis of photoreceptor cells increase significantly. As the laser power of TTT increases, the retinal tissues become swollen, degenerated and even necrotic; cellular apoptosis gradually involves the inner nuclear layer and ganglion cell layer. (Chin J Ocul Fundus Dis, 2006, 22:249-252)
目的 建立柱前衍生化反相高效液相色谱-荧光检测法测定血浆中同型半胱氨酸（Hcy）浓度的方法。 方法 以tris-(2-carboxylethyl)-phosphine hydrochloride （TCEP）为还原剂，以7-fluorbenzo-2-oxa-1,3-diazole-4-sulfonate （SBD-F）为衍生剂，色谱柱为Xterra RP18柱，柱温35℃，流动相为甲醇︰磷酸二氢钠缓冲液（pH值3.0）=3︰97，激发波长380 nm，发射波长510 nm，外标法定量。 结果 Hcy浓度在1.95～125 ?mol/L范围内线性关系良好（r=0.999 8）。日内和日间相对标准偏差均＜7%，方法回收率为103.2%～111.9%。 结论 此方法准确、灵敏、快速，是一种适合于实验室研究和临床检测血浆中Hcy浓度的方法。