First trimester, second trimester, and integrated screening for Down's syndrome in China.

OBJECTIVE: To compare the effectiveness of first trimester, second trimester, and integrated screening for Down's syndrome. SETTING: Two prenatal diagnosis centres in China. METHODS: A total of 11,966 pregnant women (≥18 years) were screened over 21 months. First trimester screening (11-13 weeks) comprised measurement of serum free beta-human chorionic gonadotrophin (ß-hCG) and pregnancy-associated protein-A concentrations, and fetal nuchal translucency thickness. Second trimester screening (15-20 weeks) comprised measurement of ß-hCG and alpha fetoprotein concentrations. Computer software was used to calculate the risk of carrying a Down's syndrome fetus. RESULTS: The overall incidence of Down's syndrome was 0.2% (23/11,966). When the false-positive rate was fixed at 5%, detection rates for first trimester, second trimester, and integrated screening were 73.9%, 69.6%, and 82.6%, respectively. When the false-positive rate was fixed at 3%, detection/sensitivity rates for first trimester, second trimester, and integrated screening were 65.2%, 56.5%, and 73.9%, respectively. CONCLUSIONS: These findings suggest that integrated screening was the most effective means of screening for Down's syndrome in a Chinese population.

[First trimester and second-trimester integrated screening for Down's syndrome].

OBJECTIVE: To evaluate the effect of first and second-trimester integrated screening so as to provide an efficient screening protocol for Down's syndrome. METHODS: Using the dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA), the freeßhCG (beta human chorionic gonadotropin), PAPP-A (pregnancy associated plasma protein-A) and NT (nuchal translucency) value of type B ultrasound were assayed in the pregnancy serum during the first trimester (11-13W(+6) d) and free ßhCG and AFP (alpha fetoprotein) during the second trimester(15-20W(+6) d). By the risk calculation software, the risks during both trimesters and their integrated risk were calculated for each patient respectively. Amniocentesis and venepuncture were employed for diagnosing the high-risk patients (> 1/270). Electronic network follow-up was carried out after delivery. RESULTS: In a total of 4237 pregnant women, 98 were found to carry a high risk during the first trimester, 241 during the second trimester and 101 during the integrated screening respectively. And 2, 3 and 4 cases were diagnosed with Down's symptom at a detection rate of 50%, 75% and 100% and a detection efficiency of 1:50, 1:80 and 1:25 respectively. CONCLUSION: Integrated screening is superior to either the first or second-trimester screening. With a lower false positive rate and a higher detection rate, it reduces the chance of invasive puncture. Advanced type B ultrasonic technology is needed to improve the first-trimester diagnostic efficiency and to develop a better integrated screening protocol.

[Cytoskeleton rearrangements and induced apoptosis in human umbilical venous endothelial cell and WISH cell lines during the invasion of Staphylococcus aureus].

OBJECTIVE: To investigate the changes of cytoskeleton and induced apoptosis in human umbilical venous endothelial cells (HUVEC) and WISH cells during the invasion of Staphylococcus aureus. METHODS: S. aureus suspension was collected routinely and used to infect HUVEC and WISH cells for 10, 30, 60 and 120 min respectively. The cell-invading ability of S. aureus was observed by microscope and the rearrangement of cytoskeleton of these cells observed under fluorescent microscope. DAPI fluorescent staining and DNA agarose electrophoresis were performed to analyze the apoptosis in HUVEC cells induced by S. aureus. RESULTS: There was bacterial invasion after staphylococcus aureus was co-incubated with HUVEC and WISH cells for 10 min. The rates of infection were (54.9 +/- 2.4)% and (56.1 +/- 2.4)% at 60 min respectively. The ratios of F-actin rearrangements at 10 min, 30 min, 60 min and 120 min after the invasion of HUVEC and WISH cells with S. aureus were different at (54.7 +/- 2.8)%, (63.0 +/- 2.9)%, (71.0 +/- 2.6)%, (39.5 +/- 2.7)% and (63.3 +/- 2.6)%, (65.0 +/- 2.9)%, (77.0 +/- 2.4)% and (44.0 +/- 1.8)% respectively. The ratios of F-actin rearrangements at 10 min, 30 min and 60 min were higher than those at 120 min (P < 0.05). There was no change of microtubule observed in both cells at the same time. The apoptotic appearance was observed after the invasion of HUVEC cells with s. aureus at 60 min. CONCLUSION: S. aureus may invade the HUVEC and WISH cells through F-actin rearrangement. Apoptosis is induced in HUVEC cells at 60 min.