Birth defects data from surveillance hospitals in Dalian city, China, 2006-2010.

OBJECTIVE: The objective of this study is to disclose characteristics of birth defects in perinatal infants in Dalian and provide an epidemiological basis for controlling birth defects. METHODS: Data used in this study were collected from surveillance hospitals in Dalian during 2006-2010. Comparison analysis and trend analysis were conducted by performing Chi-square tests. RESULTS: The perinatal prevalence of birth defects from 2006 to 2010 was 101.14 per 10 000 live births and was decreased by about 29% from 115.49 per 10 000 live births in 2006 to 81.16 per 10 000 live births in 2010. The prevalence in urban was higher than that in rural areas significantly. The three leading birth defects were congenital heart disease, cleft lip and/or palate, and polydactyly or syndactyly. About 572 cases identified by antenatal diagnosis were terminated pregnancy before 28 weeks of gestation, so the prevalence of birth defects would decrease from 126.29/10 000 to 101.14/10 000. CONCLUSIONS: Dalian has experienced a decreasing temporal trend of birth defects' prevalence; however, it is still confronted with the challenge to reduce the prevalence of birth defects. Congenital heart diseases are the focus to prevent birth defects. It is necessary to keep the surveillance system function properly, provide preconception health care service extensively, and improve the ability of prenatal diagnosis.

[Effects of Ginkgo biloba extract against excitotoxicity induced by NMDA receptors and mechanism thereof].

OBJECTIVE: To observe the effects of Ginkgo biloba extract (GBE) on N-methyl-D-aspartate (NMDA) excitotoxicity and focal cerebral ischemia, and further explore the neuroprotective mechanisms of GBE. METHODS: Neonatal SD rat hippocampus was taken out to make into cell suspension. immunohistochemistry with neuron nucleoprotein monoclonal antibody (NeuN) was used to calculate the percentage of NeuN positive cells. Twelve days after incubation the suspension of neurons were randomly divided into 4 groups: normal control group (exposed to normal saline for 15 min and then to DMEM without NMDA and glycine for 24 h), NMDA group (exposed to culture fluid with NMDA of the terminal concentration of 100 micromol/L and glycine of the terminal concentration of 10 micromol/L for 15 min and then to DMEM without NMDA and glycine for 24 h), MK-801 group (exposed to MK-801, an NMDAR antagonist, for 2 min, to culture fluid with NMDA for 15 min, and then to DMEM without NMDA and glycine for 24 h), and GBE pretreatment group (exposed to GBE of the terminal concentration of 150 microg/ml for 3 d, culture fluid with NMDS for 15 min, and then to DMEM without NMDA and glycine foe 24 h). Trypan blue staining was used to calculate the survival rate of the neurons. The lactic dehydrogenase (LDH) level in the supernatant of cultured cell suspension was detected. Whole-cell patch clamp recording was carried out to evaluate the modulatory effects of GBE on NMDA-activated currents in the rat hippocampal neurons. 108 SD rats were randomly divided into 5 groups: sham operation group (n = 12), standard middle cerebral artery occlusion (MCAO) group (n = 24, undergoing MCAO and then reperfusion), MK-801 acute administration group (n = 24, undergoing MCAO and immediate peritoneal administration of MK-801 1 mg/kg), GBE acute administration group (n = 24, undergoing peritoneal injection of GBE 100 mg/kg immediately after the MCAO), and GBE pretreatment group (n = 24, undergoing peritoneal administration of GBE every day for 7 days before the MCAO). The 4 groups were re-divided into 4 subgroups with 3 approximately 4 rats: 0.5 h ischemia, and 3 h, 1 d, and 7 d ischemia-reperfusion (IR) subgroups. The neurological symptoms were evaluated by Longa's scoring after the rats became conscious. The rats were killed at different time-points, their brains were taken out to undergo 2, 3, 5-triphenyl-tetrazolium chloride staining, the areas of cerebral infarction were calculated, and immunohistochemistry was used to evaluate the contents of NeuN and microtubule-associated protein (MAP-2). RESULTS: The cell viability of the GBE group was 85% +/- 5%, significantly higher than that of the NMDA group (39.8% +/- 2.1%, P < 0.01), and significantly lower than that of the MK-801 group (93.8% +/- 2.7%, P < 0.05). The LDH efflux of the GBE group was 87 U/L +/- 8 U/L, significantly lower than that of the NMDA group (138 U/L +/- 12 U/L, P < 0.01) and significantly higher than that of the MK-801 group (47 U/L +/- 7 U/L, P < 0.05). The inward current (I(NMDA)) of the NMDA group was significantly activated, The inhibitory rate of the NMDA-activated I(NMDA) of the GBE group was 40% +/- 17%, significantly lower than that of the MK-801 group (78% +/- 18%, P < 0.05); After washing out with standard extracellular solution, the I(NMDA) could recover to 91% +/- 8% in the GBE group, but not in the MK-801 group (P < 0.05), which indicated that GBE had lower affinity to NMDA receptor than MK-801. The Longa's scores of the 3 h and 24 h IR subgroups of the GBS pretreatment group were all significantly lower than those of the corresponding subgroups of the standard MCAO and GBE acute administration groups. The symptoms of the MK-801 were the most severe. Cerebral infarction began to appear in the 1-day subgroups. The cerebral infarction areas of the 1 d subgroups of the GBF pretreatment and MK-801 groups were 11.5% +/- 1.3% and 6.5% +/- 0.9% respectively, both significantly smaller than those of the MCAO and GBE acute administration groups (24.5% +/- % and 22.9% +/- 1.3% respectively, both P < 0.01), however, there was no significant difference in the cerebral infarction area between the GBE acute administration and MCAO group. It was true too for the cerebral infarction areas of the 7 d subgroups. Except in the control group, loss of NeuN positive neuron was seen in all groups, especially the MCAO and GBE acute administration groups. Except in the control group, the MAP-2 positive neurons were decreased in all groups, especially the MCAO and GBE acute administration groups, and 1 day and 7 days after the IR MAP-2 positive neurons were almost unseen in the MCAO and GBE acute administration groups, however, could be seen in small amounts in the GBE and MK-801 groups (all P < 0.01). CONCLUSION: GBE pretreatment protects the neurons from excitotoxicity induced by over-activated NMDA receptor and focal cerebral ischemia, which can be explained by the mild blocking effect of GBE on NMDA receptor with low affinity, comparing with MK-801, and GBE is expected to interfere in excitotoxicity in clinic without neurotoxic behaviors.