A Novel and Reversible Experimental Primate Ocular Hypertension Model: Blocking Schlemm's Canal.

INTRODUCTION: The purpose of this study was to establish a novel and reversible experimental ocular hypertension primate model by blocking Schlemm's canal. METHODS: A model was induced in adult cynomolgus monkeys (n=4) by blocking Schlemm's canal with an inserted microcatheter (200 µm diameter); it was removed 6 weeks later from one monkey to reverse the elevated intraocular hypertension. All animals were monitored for 11 months; weekly measurements of intraocular pressure and biweekly examinations with spectral domain optical coherence tomography and disc photography were performed. Histopathology of the eye and retinal ganglion cell counts were completed at the end of the study. RESULTS: The intraocular pressure of the blocked eyes was significantly higher than that of the contralateral eyes at 1 month after the blockage (P <0.001); the mean intraocular pressure was similar to the contralateral eye from 1 week to 11 months after the microcatheter was removed in monkey A (P=0.170). The mean intraocular pressure of the blocked eyes of the remaining monkeys was significantly higher than that of the contralateral eyes throughout the follow-up period (P <0.001). The fundus imaging showed decreases in the retinal nerve fibre layer thickness, and localised defects were observed in two blocked eyes. A histological examination demonstrated that the number of retinal ganglion cells in blocked eyes of monkeys A, B, and C was significantly decreased compared with the control. CONCLUSION: Schlemm's canal blockage alone in the monkey model produces sustained elevation of intraocular pressure, which present a novel animal model for studying the pathogenesis of glaucoma.

[Study on absorption and accumulation of mercury in rats by repeated administration of Yuhong ointment].

OBJECTIVE: To study in vivo mercury absorption and accumulation through repeated transdermal administration of Yuhong ointment containing calomel, in order to provide scientific evidences for clinical safe medication. METHOD: A total of 100 SD rats were randomly classified into five groups: the control group, the Yuhong ointment group, the double-concentration Yuhong Ointment group, the quadruple-concentration Yuhong ointment group and the 1.6% calomel group. The rats were treated with the dosage of 0.04 g . cm-2 by repeated transdermal administration for 2, 4 weeks. After the drug discontinuance for 4 weeks, the levels of mercury in blood, urine, and tissues of heart, liver, brain and kidney were determined, respectively. RESULT: Compared with the control group, the blood mercury level of the Yuhong ointment group show no obvious change after treatment for 4 weeks. However, the levels of mercury in blood and urine of other experimental groups increased significantly with time and the increase in dosage, and so did the level of mercury in major organ. At 4 weeks, all experimental groups showed increase in the content of mercury, and kidneys displayed the highest level, whereas brain displayed the lowest level After the drug discontinuance for 4 weeks, the mercury level in blood and urine of every dose group recovered to normal, with significant decline in the content of mercury in each organ. CONCLUSION: After transdermal administration in rats for 4 weeks, there was no obvious absorption of mercury in blood. Mercury was mainly accumulated in kidneys and excreted through urine. The results suggest that the patients' mercury content and kidney function indexes need to be monitored in long-term clinical use of Yuhong ointment.

[Determination of mercury content in yuhong ointment by wet catalytic digestion-atomic absorption spectrometry].

OBJECTIVE: To develop a method for determining the content of mercury contained in Yuhong ointment. METHOD: The wet catalytic digestion method was adopted for the pretreatment, and the mercury content in Yuhong ointment was determined by hydride generation-atomic absorption spectrometry (HG-AAS). RESULT: The mercury showed a good linear relation in the range from 2 to 20 microg x L(-1), with the average recovery of 104.27% and RSD of 3.37%. The RSD for real sample repeated measurement was determined to be 8.4%. The mercury content in Yuhong ointment was detected in range from 0.7 to 1.5 mg x g(-1). CONCLUSION: The proposed method is accurate, highly reproducible and it can be used to control mercury content of Yuhong ointment.

[The influence of ambient air pollutants on outpatient visits for allergic disease and pollinosis].

OBJECTIVE: To assess the effects of ambient air pollutants on hospital outpatient visits for allergic disease and pollinosis. METHODS: The monitoring data of daily air pollution (SO(2), NO(2) and PM(10)) in 8 national monitoring and controlling sites of Beijing air quality, airborne pollen in 4 monitoring sites of Beijing, and daily meteorological data, along with the daily numbers of outpatients visits for allergic disease and pollinosis at the Allergy Department of Beijing Shijitan Hospital from April to September in 2004 were collected. Associations between the levels of air pollutants and outpatient visits for allergic disease and pollinosis were estimated by time serial analysis using a generalized addictive model (GAM), considering lag effect and the influence of multipollutants. RESULTS: During the study period, the average daily ambient concentrations of SO(2), NO(2) and PM(10) were (20.9 ± 12.9), (58.6 ± 13.6) and (126.8 ± 64.1) µg/m(3), respectively. The mean daily pollen count was (163.8 ± 209.0) grains/1000 mm(2), while the average daily numbers of doctor visits for allergic disease and pollinosis were (16.3 ± 5.3) and (3.5 ± 5.0), respectively. Time serial analysis showed that significant positive associations were found between levels of airborne pollen and doctor visits, with an excess risk (ER) of 2.44% (95%CI: 0.75% - 4.13%)for allergic disease and 6.58% (95%CI: 3.82% - 9.34%) for pollinosis per 100 grains/1000 mm(2) increase in pollen, in single-pollutant models. There were associations between ambient air pollutants (SO(2), NO(2), PM(10)) and doctor visits with lag effects. A 10 µg/m(3) increase in NO(2) was associated with a 3.14% (95%CI: 0.42% - 5.85%) increase in doctor visits for allergic disease at lag 6 d. For pollinosis, the highest ER was observed for 10 µg/m(3) increases in SO(2) at lag 1 d, NO(2) at lag 6 d, PM(10) at lag 3 d. However, this association was not statistically significant (RR (95%CI) were 1.0460 (0.9640 - 1.1280), 1.0325 (0.9633 - 1.1017), 1.0079 (0.9942 - 1.0217), respectively). The associations enhanced slightly in multi-pollutant models with an ER of 2.56% (95%CI: 0.80% - 4.31%) for allergic disease and 6.81% (95%CI: 3.91% - 9.71%) for pollinosis per 100 grains/1000 mm(2) of pollen. CONCLUSIONS: Our results suggest that level of airborne pollen may have a stronger effect than ambient air pollutants on allergic disease and pollinosis.