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Objective@#To investigate the season, age and gender distribution of Mycoplasma pneumoniae (MP) infection in children in Beijing, and to analyze the epidemiological characteristics of MP infection.@*Methods@#A total of 4 271 children with community acquired pneumonia hospitalized at the Respiratory Department of Children′s Hospital Affiliated to Capital Institute of Pediatrics were collected between January 2006 and December 2015.MP 16S rRNA and tandem repeat locus-Mpn16 were amplified by nested polymerase chain reaction(PCR).@*Results@#Among 4 271 specimens, 1 042 were positive for MP by PCR, and the positive rate was 24.4% (1 042/4 271 cases). There were 3 MP outbreaks (2006-2007, 2012-2013 and 2015, respectively). The positive rate was up to 44.6% in the epidemic year, but as low as 13.0% in the non-epidemic year.The positive rates of MP in spring, summer, autumn and winter were 21.2% (217/1 022 cases), 22.0% (230/1 044 cases), 28.9% (320/1 108 cases) and 25.1% (275/1 097 cases), respectively.There were mild epidemic peaks in April to May and August to September every year.The infection rates of MP in autumn were significantly higher than those in other 3 seasons(χ2=16.50, 13.30, 4.07, all P<0.05). The positive rates of children in each age group were 10.6% (69/651 cases) in < 1 year old group, 17.5% (216/1 233 cases) in 1- 2 years old group, 28.5% (369/1 294 cases) in 3-6 years old group, and 35.5% (388/1 093 cases) in > 7 years old group, respectively.The positive rate of preschool and school-age children was 31.7% (757/2 387 cases), which was higher than that of the infants (15.1%, 285/1 884 cases), and there was a statistical significance (χ2=157.0, P<0.05). The positive rate of MP in girls was 28.3% (481/1 699 cases), which was significantly higher than that in boys [21.8% (561/2 572 cases)], and there was a statistical significance (χ2=23.4, P<0.05), especially during the epidemic years.@*Conclusions@#The detection rate of MP infection in children in Beijing is high in autumn and winter, and low in summer.The positive rate of MP increases with age.The high incidence of MP infection is in preschool and school-age children, especially girls.There is a significant difference between the prevalence of MP infection and the prevalence intervals.The prevalence of MP infection may be closely related to the long-term closed and semi-closed living habits.
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Objective To investigate the potential association between 163A/G and 950T/C polymorphisms of osteoprotegerin(OPG)gene and severe pre-eclampsia.Methods Eighty-five severe preeclamptic patients and 81 normal term pregnant women(as control group)were recruited from the Department of Obstetrics and Gynecology,West China Second University Hospital,Sichuan University during the period from July 2007 to March 2009,and they were all Han population living in Chengdu,China.Genotype and allele frequencies of 163A/G and 950T/C were determined by the PCR-restriction fragment length polymorphism(RFLP)assay.Clinical and biochemical parameters for different alleles between the patients and controls were compared for statistical significance respectively,such as blood pressure,serum creatinine and 24-hour urine protein.Results The observed and expected genotype counts were consistent with Hardy-Weinberg equilibrium.No significant differences were found in the genotype and allele frequencies of 163A/G and 950T/C polymorphisms between the two groups(P ＞ 0.05).However,in the preeclamptic group,serum creatinine was significantly higher in women with the AG + GG genotypes [(76 ±24)μmol/L]compared with AA genotype[(56 ± 18)μmol/L].Reversely,birth weight was lower in the AG + GG genotypes[(2040 ± 721)g]than those in the AA genotype[(2520 ± 810)g],and the P ＜0.05,respectively.In the severe pre-eclampsia,950T/C TT genotype carriers exhibited significantly higher systolic blood pressure[(153 ± 16)mm Hg(1 mm Hg =0.133 kPa)]and 24-hour urine protein [(4.0±2.5)g]compared with TT + TC carriers[(145 ±17)mm Hg,(2.9±1.8)g],respectively,furthermore the P ＜ 0.05.Conclusions In severe pre-eclampsia,carriers with G allele at position 163A/G has more genetic predisposition than A allele carriers,as well as 950T/C T allele carriers compared with C carriers.Taken together,this study suggested that OPG gene polymorphisms might be associated with some clinical parameters of severe pre-eclampsia.
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Objective To evaluate the prognostic significance of metastastic lymph node ratio in patients with gastric cancer. Methods Clinical data of 319 patients with gastric cancer who underwent radical gastrectomy with at least 15 lymph nodes dissected per patient were analyzed retrospectively. Patients were divided into 4 groups according to the TNM staging system (1997,5th edition): pN0 (no positive lymph node), pN1(with 1～6 metastatic lymph nodes), pN2 group (with 7～15 metastatic lymph nodes), and pN3 group (with more than 15 metastatic lymph nodes), or into 4 groups according to the lymph node metastatic ratio: rN0 group (without metastasis of lymph node), rN1 group (with a lymph node metastatic ratio of <30%), rN2 group (with a lymph node metastatic ratio of 30%～60%), and rN3 group ( with a lymph node metastatic ratio of >60%). Survival was determined by the Kaplan-Meier method and differences were assessed by the Log-rank test. Multivariate analysis was performed using the COX proportional hazard regression model in forward stepwise regression with SPSS 13.0. Results Kaplan-Meier survival analysis demonstrated that the metastatic lymph node ratio significantly influenced the postoperative survival time. According to the lymph node metastasis system 77 patients were in group 1, 109in group 2, 60 in group 3, and 73 in group 4. The 2-year survival rate was 84.4%,66.1%, 35.0%,and 15.1% respectively, 3-year survival rate was 80.5%,45.0%,15.0% and 5.5% respectively, and 4-year survival rate was 71.4%,33.0%,5.0% and 1.4% respectively. If cases with the same positive number of lymph node (pN) group were stratified futher by lymph node metastatic ratio, there were no significant differences in the 3-year survival rate among the new rN groups (P>0.05), but there was a great difference in the distribution of prognosis among different groups. COX proportional hazard regression model analysis showed that the metastatic lymph node ratio was an independent factor for poor prognosis. Lymph node metastatic ratio was closely related with the location, modality of the operation and infiltration depth. Conclusions The staging system based on metastatic lymph node ratio is more reliable than the system based on the number of metastatic lymph nodes in the prediction of the prognosis of gastric cancer.