消防第一出动时间的频次分布规律研究

消防队接到火警后第一出动力量及时到达火场展开灭火救援,对有效控制火灾、减少人员伤亡和财产损失有着重要的意义。第一出动时间直接反映了城市灭火救援专业力量的出动响应水平。采用SPSS软件对1995-2003年日本全国城市火灾数据进行分析,发现第一出动时间的频次符合对数正态分布;与部分中国城市火灾统计数据对比后,表明后者符合同样的规律。中国数据对数正态分布的期望值为4.9分钟,其物理意义为消防力量第一出动时间的平均值,与我国消防条例对城镇消防站设置的基本原则相符。     

Maternal serum leptin concentration during the second trimester of pregnancy: association with fetal chromosomal abnormalities

Recent studies suggest that leptin, the product of the obese gene, is produced by the placenta during pregnancy. The present study addressed the question whether second trimester maternal serum leptin could be altered by fetal Down syndrome or Edwards syndrome. Maternal serum leptin concentrations were measured in 18 pregnancies complicated with Down syndrome, six pregnancies complicated with Edwards syndrome and 183 uncomplicated pregnancies during the second trimester of pregnancy. The present results demonstrate that leptin concentrations in uncomplicated pregnancies slightly decrease from the 16th week of pregnancy, reaching a minimum of 18.8 ng/ml around the 20th week, and then rapidly increase to 28.2 ng/ml by the 24th week. Leptin correlation with maternal body weight decreases from r=0.695 at 16–17 week of gestation to r=0.544 at >22 weeks of gestation. There was no significant difference between the mean MoMs of Down syndrome- (0.926) or Edwards syndrome- (0.960) affected pregnancies and normal pregnancies (1.002). A weak correlation (r=0.18, p<0.02) was observed between corrected leptin MoMs and human chorionic gonadotrophin (hCG) MoMs in normal pregnancies. It is assumed that around the 20th week of pregnancy placental leptin production is activated or at least is accelerated and it is added to the amount of leptin produced by maternal adipose tissue. Fetal Down syndrome or Edwards syndrome does not seem to alter maternal leptin concentration and therefore leptin cannot be used as a marker for these chromosomal abnormalities in the early second trimester of pregnancy. Copyright © 2002 John Wiley & Sons, Ltd.     

First-trimester maternal serum human thyroid-stimulating hormone in chromosomally normal and Down syndrome pregnancies

Maternal serum human thyroid-stimulating hormone (TSH) levels were investigated in chromosomally normal and Down syndrome pregnancies to determine whether TSH can be used as a marker for Down syndrome in the first trimester. Measurements were conducted on stored serum samples collected from 23 Down syndrome pregnancies and 115 unaffected pregnancies before chorionic villus sampling (CVS), between 9 and 11 completed weeks of pregnancy. The samples were matched for gestational age, maternal age, maternal weight and duration of storage of the serum sample. Maternal TSH concentration was slightly decreased in Down syndrome pregnancies, with a median of 0.84 multiples of the median (MoM). Maternal serum human chorionic gonadotropin (hCG) concentration was slightly elevated in Down syndrome pregnancies, with a median of 1.03 MoM. Both differences were not significant applying matched rank analysis (p=0.50 for TSH and p=0.43 for hCG). The association between TSH and hCG in unaffected pregnancies was also measured. The Spearman correlation coefficient between TSH and hCG was −0.21 which was statistically significant (p=0.02, 95% confidence interval −0.38 to −0.03). However, it was concluded that TSH is not a useful marker for distinguishing Down syndrome-affected pregnancies from normal pregnancies in the first trimester. Copyright © 2001 John Wiley & Sons, Ltd.     

Trisomy 10: ultrasound features and natural history after first trimester diagnosis

We report on the ultrasound features and natural history of trisomy 10. At 12 weeks' gestation in a routine scan examination, the fetus presented with increased nuchal translucency thickness, mild skin oedema, bilateral pleural effusion, marked micrognathia, cardiomegaly, unilateral talipes and reversed A-wave in the ductus venosus blood flow. Karyotyping on chorionic villus sampling (CVS) led to the diagnosis of trisomy 10, which was confirmed by fetal blood sampling at 22 weeks' gestation. As the parents opted to continue with the pregnancy, the natural history and following ultrasound features are described. This is the third case of trisomy 10 in the literature reporting on the physical features. The most frequent ultrasound findings presented in trisomy 10 are increased nuchal translucency, micrognathia, renal agenesis, facial cleft, limbabnormalities, cardiac defects and early severe growth retardation. Copyright © 2001 John Wiley & Sons, Ltd.