Safety and efficacy of photodynamic therapy using BCECF-AM compared to mitomycin C in controlling post-operative fibrosis in a rabbit model of subscleral trabeculectomy

AIM： To evaluate the safety and efficacy of cellular photoablation using BCECF-AM [2, T-bis-（2-carboxyethyl） -5-（and-6）-carboxyfluorescein, acetoxymethyl ester mixed isomersl as a method to control postoperative fibrosis in subscleral trabeculectomy （SST） compared to mitomycin C （MMC） in a rabbit model. METHODS： A comparative prospective case-control animal study was conducted. Fourteen rabbits were subjected to SST with intraoperaUve use of wound modulating agents （MMC or BCECF-AM） of the right eye （study groups I and II respectively） and SST without use of intraoperative wound modulating agents for the left eye （control group II）. Two rabbits 4 eyes were considered as control group I with no surgical intervention. BCECF-AM was injected subconjunctivally 30min before surgery followed by intraoperative illumination with diffuse blue light for 10min. Antifibrotic efficacy was established by clinical response and histological examination. Clinical response was assessed by measuring intraocular pressure （lOP） at day 1, 3, 5, 7, 14, 21 postoperatively, Success was defined by 〉20.0% reduction in lOP from the preoperative values without anti-glaucoma medications. RESULTS： The mean percentage of reduction was 35.0% in the study group I with only one eye （14.3%） had 12.5% reduction. The mean percentage of reduction was 28.0% in the study group U with two eyes （28.6%） in study group II had 14.2% reduction each. Regarding the control group II, the mean percentage of reduction was 14.3% with 64.3% eyes had 〈20.0% reduction. There was a highly statistically significant difference between each of the study groups （right eyes） and the corresponding control group II （left eyes） as regards the mean postoperative lOP values started from day 5 in both study groups and this highly significant difference remained so till the end of the follow up period. Histologically, MMC treated blebs showed thinning of conjunctival epithelium with marked reduction of the goblet cells relative to control. Marked sub-epithelial edema was seen along with variable collagen dispersion. Mild cellularity was noted in sub-epithelial tissue. BCECF-AM treated blebs showed normal conjunctival epithelial thickness with abundant goblet cells. Mild sub- epithelial edema was noted along with moderate collagen dispersion. No histological abnormality was noted in the ciliary body or the cornea in any of the studied groups. CONCLUSION： Cellular photoablation using BCECF-AM is a safe and effective wound modulating agent to control postoperative fibrosis in trabeculectomy. However MMC considered as a more potent adjuvant to trabeculectomy than BCECF-AM in promoting IOP reduction.

盐胁迫下谷子根部细胞内pH值测定

利用BCECF-AM荧光染料和激光共聚焦显微镜测定谷子根部细胞内的荧光强度,进而换算成细胞内pH值,以此来研建测定谷子根部细胞内pH值的方法。结果显示:正常水培条件下,谷子品种YG2和AN04根部细胞内pH值分别为5.85±0.11和5.77±0.26;盐处理下YG2和AN04根部细胞内pH值分别达到6.21±0.26和6.19±0.17,即盐敏感品种AN04根部细胞盐处理后pH值变化较大,提高7.28%,而抗盐品种YG2提高6.15%。这说明抗盐品种盐胁迫下细胞内pH值受外界环境影响较小,对盐害的耐受力较高。该方法用来定量测定细胞内pH值具有可信性,亦可作为评价植物耐受胁迫能力的辅助手段。

Amiloride对离体自发高血压大鼠心肌肥厚的影响

目的:观察amilorid(阿米洛利)对自发高血压大鼠(spontaneously hypertensive rat,SHR)心肌细胞内pH值(pHi)的影响。方法:胶原酶灌流分离得到单个心室肌细胞,以pH荧光染色剂BCECF/AM染色后,在激光共聚焦显微镜(laser scanning confocal microscopy,LSCM)下,测量细胞内的荧光强度。结果:SHR对照组心肌细胞内荧光强度比正常SD大鼠对照组显著升高(P<0.01);高剂量、低剂量amiloride组和enalapril组心肌细胞内的荧光强度与SHR对照组比较,均明显下降(P值均<0.01);amiloride组低于enalapril给药组(P<0.01)。结论:SHR心肌细胞内pHi明显升高。amiloride,enalapril可以降低SHR心肌细胞内pHi,amiloride的作用比enalapril更明显。

环境pH值与活态红细胞的形态和胞内pH值的关系

目的:研究活态红细胞的形态和胞内pH值随环境pH值的变化情况。方法:①利用多维显微图象分析技术,在无损、在位、实时的情况下,测定红细胞形态的相关参数在不同外界pH下的变化情况;②采用对pH值敏感的荧光染料BCECF AM测量活体红细胞内pH值随外界pH环境的变化情况。结果:①红细胞的圆度随环境pH值的下降而显著增加,接触面积随环境pH值的升高而显著下降。②胞内pH值随胞外pH值的变化而相应改变,且这种关系从总体上来说是线性的,并可用一个确定的函数式来表示。结论:环境pH值偏离正常生理条件会引起红细胞的形态和胞内pH值的改变,进而对红细胞的变形性和携氧功能产生影响。