[Expression of vitronectin in placental basal plate and its relationship with the pathogenesis of severe preeclampsia].

OBJECTIVE: To investigate the expression of vitronectin (VN) in placental basal plate and its relationship with the pathogenesis of severe preeclampsia. METHODS: From March 2010 to December 2011, 17 patients with early-onset severe preeclampsia who delivered in the Second Hospital of Jilin University were recruited as the early-onset severe preeclampsia group; and 16 women were recruited as the late-onset severe preeclampsia group. Meanwhile, 15 healthy pregnant women who delivered before 34 weeks were defined as the early control group (termination of pregnancy was carried out because of fetal heart malformations), and 15 healthy pregnant women delivered after 34 weeks were defined as the late control group. Immunohistochemistry and semi-quantitative reverse transcription (RT)-PCR were used to investigate the expression of VN protein and mRNA in the placental infarct center and its surrounding tissue of placental basal plate. The levels of serum prothrombin time (PT), part thromboplastin time (APTT) and fibrinogen (FIb) were detected and the international normalized ratio (INR) was calculated. The correlation of abnormal coagulation markers and VN expression levels in the early-onset severe preeclampsia group and the early control group was studied. RESULTS: (1) VN protein was detected in all placental basal plate of the four groups. It was highly expressed in the necrotic tissue of placental infarct center and weakly expressed in the tissue far from the infarcted area. (2) The mean levels of VN protein expression in placental basal plate of the early-onset severe preeclampsia group, the late-onset severe preeclampsia group, the late control group and the early control group were 0.152 ± 0.019, 0.113 ± 0.023, 0.095 ± 0.014 and 0.055 ± 0.010, respectively. And the differences between the groups were statistically significant (P < 0.01). The VN protein expression in placental infarct center, infarct edge, peri-infarct tissue and tissue far from the infarcted area gradually reduced, and the differences were statistically significant (P < 0.01). Compared with the same areas of each group, the differences were not statistically significant (P > 0.05). (3) VN mRNA were detectable in infarct center, infarct edge, per-infarct tissue and tissue far from the infarcted area of placental basal plate. In the early-onset severe preeclampsia group and the early control group, it was statistically higher in infarct center than in tissue far from the infarcted area (P < 0.05). (4) PT of the early-onset severe preeclampsia group was (9.45 ± 0.63) s, significantly shorter than that of the early control group [(9.88 ± 0.17) s, P < 0.05]. While there was no statistically significant difference in APTT, FIB and INR among the four groups (P > 0.05). (5) In the early-onset severe preeclampsia group, VN expression level and PT were significantly negative correlated (r = -0.612, P < 0.05); while in the early control group there was no correlation (r = 0.489, P > 0.05). CONCLUSION: VN was highly expressed in placental basal plate of the early-onset severe preeclampsia group, which caused the imbalance of coagulation and fibrinolysis system and the pathogenesis of severe preeclampsia.

[Effects of long-term fertilization on soil microbial abundance in farmland of the Loess Plateau, China]. / 长期施肥对黄土旱塬农田土壤微生物丰度的影响.

Based on a long-term experiment in the Changwu Agro-ecological Experimental Station, the real-time PCR analysis was used to examine the soil microbial abundance and to reveal the effects on soil microbial community under different long-term fertilization systems. The results showed that compared to the CK (barren field), the population of bacteria increased by 21% and archaea by 32% in treatment with inorganic fertilizer application. The abundance of bacteria in the treatment of chemical fertilizer combined with organic fertilizer increased by 37% and archaea by 36%. The treatment with chemical fertilizer mixed with organic fertilizer significantly increased the abundance of bacteria and archaea. The soil AOB increased by 7.13 times while the soil AOA only by 0.2 folds after 30-year application of chemical nitrogen fertilizer. AOB was highly responsive to fertilizer application, especially to nitrogen fertilizer. Compared with the single nitrogen application and the application of nitrogen fertilizer mixed with organic fertilizer, phosphorus fertilizer significantly increased the abundance of nifH and pmoA. The content of nifH, nirS cd and pmoA in the abandoned land was significantly higher than that in the cultivated soil. Results from the correlation analysis on soil basic physical and chemical properties indicated that soil pH, total nitrogen and organic carbon were key factors affecting soil microbial community abundance. In conclusion, long-term fertilization significantly changed soil microbial abundance, and fertilization patterns and cultivating methods had significant effect on microbial community abundance.

[Epidemiological and clinical analysis of Mycoplasma pneumoniae infection in children with acute respiratory tract infection].

OBJECTIVE: To summarize the epidemiology and clinical characteristics of Mycoplasma pneumoniae (MP) infection in children with acute respiratory tract infection (ARI) in Guangzhou. METHODS: MP was detected using an indirect immunofluorescent method in 2084 children with ARI. The relations between MP infection rate and the gender, age, season, site of infection and wheezing diseases were analyzed. RESULTS: A total of 433 children (20.8%) were positive for MP, including 222 boys (19.8%) and 211 girls (21.9%) without significant difference in the infection rate between the genders (P>0.05). In 0- to 3-year-old group, 106 children were positive for MP (15.0%), while in 3- to 5-year-old group and 5- to 14-year-old group, 163 (25.2%) and 164 (22.5%) were positive, respectively, showing a significant difference in the infection rate between the 3 groups (P<0.05). The MP infection rate was 18.0% in January to March, 25.1% in April to June, 17.7% in July to September, and 20.5% in October to December, showing significant differences between the periods (P<0.05). No significant difference was found in the infection rate between children with acute upper respiratory tract infection (URI) and those with lower respiratory tract infection (LRI) (P>0.05). Among the children with LRI, those having wheezing disease had significantly higher MP positivity rate than those without wheezing. CONCLUSION: MP is a common causative agent for ARI in children. MP infection is not related to gender and infection site, but to age and season. Children over 3 years old are vulnerable to MP infection. MP infection can be associated with wheezing in LRI.