[Effects of eye exercises on axial eye elongation in junior students]

Objective: To evaluate the association between the eye exercises and one-year axial eye elongation in grade 7 students in Beijing. Methods: Sampling was performed using a multistage random cluster approach, and 1 443 students of grade 7 were selected from 9 middle schools in 6 districts for the baseline survey. Data were collected by questionnaires and axial length measurement. Multiple linear regression analysis was used to evaluate the association between eye exercises and excessive axial eye elongation. Results: Among 1 197 (82.95%) students with complete information, the median (Q_R) age was 12.00 (1.00) years old, girls accounted for 44.28%, and the median (Q_R) axial eye elongation was 0.22 (0.18) mm. In the multiple linear regression analysis, the frequency of eye exercises was significantly correlated with excessive axial eye elongation in boys (β=-0.135, 95%CI:-0.253--0.018) but not in girls (β=-0.075, 95%CI:-0.207- 0.058) after adjusting for sex, age, body height, the number of myopic parents, time spent outdoors and time spent on reading and writing outside class; while the seriousness of eye exercises was not significantly associated with axial eye elongation in boys (β=-0.028, 95%CI: -0.114-0.058) and girls (β=-0.035, 95%CI: -0.134-0.064). Conclusion: The increased frequency of eye exercises is beneficial to control the axial eye elongation in boys in Beijing.

[Kindling model of SD rats induced by injection of PTX intraperitoneally]

OBJECTIVE

To observe the kindling model of Sprague-Dawley (SD) rats induced by injection of different doses of picrotoxin (PTX) intraperitoneally, and to evaluate the effect of the drug on the model.

METHODS

SD rats were devided randomly into four groups: control group, epilepsy Group I (PTX, 1.5 mg.kg-1.d-1), epilepsy Group II (PTX, 2 mg.kg-1.d-1) and the phenobarbital group. The kindling model of rats was induced by daily injection of PTX intraperitoneally. The seizures in the rats were observed, and the results of electroencephalography (EEG) were recorded.

RESULTS

On the 20th day after injection of PTX, 71% SD rats were kindled in epilepsy Group I; 4 rats were dead, 2 rats were at stage IV of convulsions, and 2 rats were at stage V of convulsions in epilepsy Group II; 17% rats were kindled in the phenobarbital group. The EEG demonstrated spike discharges in the kindled rats.

CONCLUSIONS

In this models, the better dose of PTX is 1.5 mg.kg-1.d-1, and phenobarbital sodium can protect SD rats injected PTX intraperitoneally from seizure.