[Effects of GLAST gene knockout on phenotype and hearing in mice].

OBJECTIVE: To investigate the effects of glutamate aspartate transporter (GLAST)deletion on the normal auditory function of mice. METHODS: We hybridized GLAST+/- mice with C57BL/6J background and identified the genotypes of their offspring by agarose gel electrophoresis. 9-10-week-old mice were selected to detect the expression of GLAST protein in the cochlea by immunofluorescence staining and to verify the knockout results(n=3). The changes in weight from 7 days to 30 days after birth and the 30-day body length of male and female mice were compared(n=8). The auditory brainstem response(ABR) was used to detect the auditory threshold and the amplitude of wave I in 9-10-week-old male and female mice(n=5). RESULTS: Male GLAST-/- mice had shown significantly lower weight and body length compared to male GLAST+/+ and GLAST+/- mice(P＜0.01), and male GLAST-/- mice showed significant differences compared to GLAST+/+ from P7 to P30 statistical time. Male GLAST-/- mice exhibited a significant reduction in weight after P15 compared to male GLAST+/- mice. In contrast, no significant differences in weight and body length were observed in female GLAST-/- mice compared with female GLAST+/+ and GLAST+/- mice. There was no difference in the hearing threshold detected by ABR between the three genotypes in both male and female mice, but the amplitude of wave I in GLAST-/- mice was significantly lower than that in male GLAST+/+ mice(P＜0.01). In contrast, the amplitude of wave I in females was reduced throughout the stimulus intensity but was most significant only at high-intensity stimulation (e.g.80 dB, 90 dB) (P＜0.05). CONCLUSION: GLAST knockout affects the normal growth and development of male mice, and decreases the amplitude of wave I, but do not change the threshold, suggesting that GLAST knockout may lead to synaptic pathological changes, and there are gender differences in this effect.

[Relationship between pesticide exposure and adverse pregnancy outcomes among famers: a meta-analysis].

OBJECTIVE: To analyze the relationship between pesticide exposure and adverse pregnancy outcomes in famers. METHODS: A search was conducted to collect the articles about the relationship between pesticide exposure and adverse pregnancy outcomes published worldwide from 1990 to February 2012. Meta-analysis was performed on the collected articles using RevMan 4.2 software. RESULTS: Twelve articles were collected. Compared with the controls, the pesticide-exposed famers showed a combined odds ratio (OR) for spontaneous abortion of 1.52 (95%CI: 1.04 ∼ 2.21; P = 0.03), a combined OR for premature birth of 1.33 (95%CI: 1.09 ∼ 1.61; P = 0.005), a combined OR for dead fetus of 1.22 (95%CI: 1.16 ∼ 1.29; P < 0.01), a combined OR for stillbirth of 1.90 (95%CI: 0.58 ∼ 6.28; P = 0.29), a combined OR for birth defect of 2.02 (95%CI: 0.84 - 4.69; P = 0.12), a combined OR for low birth weight of 1.62 (95%CI: 0.60 ∼ 4.39; P = 0.34), a combined OR for neonatal death of 2.18 (95%CI: 0.54 ∼ 8.88; P = 0.28), and a combined OR for delayed conception of 1.43 (95%CI: 0.93 ∼ 2.18; P = 0.1). Pesticide exposure increased the risks for spontaneous abortion, premature birth, and dead fetus, but was not significantly associated with stillbirth, birth defect, low birth weight, neonatal death, and delayed conception. CONCLUSION: Pesticide exposure can cause adverse pregnancy outcomes in farmers, increasing the risks of spontaneous abortion, premature birth, and dead fetus.

[Delayed protection of HO-1 in the exercise preconditioning from the myocardial relative ischemic reperfusion injury].

AIM: To explore the role of HO-1 in the exercise preconditioning protecting the rat myocardium from the relative myocardial ischemia/reperfusion injury (rI/R). METHODS: 40 Wistar rats were divided into 5 groups randomly: control group (CN), relative ischemia/reperfusion group (IR), exercise preconditioning + relative ischemia-reperfusion group (EI), HO-1 revulsant group (HE) and exercise preconditioning + HO-1 inhibitor (EZ) group. We detected the cardiac function parameter--pressure-rate product (PRP), the levels of MDA in coronary effluent and the activity of HO-1. RESULTS: The activities of HO-1 of EI group and HE group were higher significantly than the IR group. EZ group was lower than EI group. There was significant difference between EI group and HE group. The recovery rate of PRP in the 60 min point of reperfusion of EI group was higher significantly than IR group. EZ group was lower than EI group. There was significant difference between HE group and IR group in 30 min point of reperfusion. The levels of MDA in coronary effluent after rI/R of EI group, EZ group and HE group were lower significantly than IR group. There was significant difference between EI group and EZ group. CONCLUSION: EP can activate the HO-1 which can ameliorate the rI/R injury occurred after 24 hours.

[The delayed protection of exercise preconditioning from the relative myocardial ischemia-reperfusion injury.].

OBJECTIVE: To explore the delayed protection of exercise preconditioning from the relative myocardial ischemia-reperfusion injury. METHODS: The experiment included the vivo experiment and the vitro experiment, 32 Wistar rats in each experiment were divided into 4 groups randomly: control group (CN), relative ischemia reperfusion group (IR), exercise preconditioning group (EP) and Exercise preconditioning + relative ischemia-reperfusion group (EI). We detected the third loading exercise time, the levels of MDA in serum in vivo experiment and the Cardiac function parameter, the levels of MDA in coronary effluent in vitro experiment. RESULTS: (1) The vivo experiment: The third loading exercise time of EI group [(71.67 +/- 9.00) min] increased significantly compared with that of IR group [(58.67 +/- 4.13) min] (P < 0.05); The levels of MDA in serum of EP group (107.00 +/- 35.99) micromol/L and EI group [(152.23 +/- 29.94) micromol/L] decreased significantly contrasted to IR group (313.20 +/- 43.40 micromol/L) (P < 0.05). (2) The vitro experiment: The PRP (heart rate * left ventricular developed pressure) in reperfusion period of CN group and EP group were stable relatively, while it reached the peak after 30 minutes and almost recovered to the level before ischemia in EI group. The parameter of IR group recovered slightly but was lower significantly than that before ischemia. There was significant difference between the recovery rate of Cardiac function of EI group and that of IR group. The increase of MDA in coronary effluent after Ischemia-reperfusion of EP group (0.34 +/- 0.24 micromol/L) and EI group [(0.41 +/- 0.26) micromol/L] decreased significantly contrasted to that of IR group [(1.27 +/- 0.52) micromol/L] (P < 0.05). CONCLUSION: EP has the obvious delayed protection from the relative myocardial ischemia-reperfusion injury.