Seroprevalence of Cytomegalovirus infection in children aged 0-8 years in Nanjing / 中华实用儿科临床杂志

Objective To investigate the seroprevalence of Cytomegalovirus (CMV) infection and ages of the children in primary for better understanding the status of CMV infection in China with evidence-based medicine.Methods Total 837 children randomly selected from Nanjing Children's Hospital,from Jun.to Sep.in 2011,including 513 boys and 324 girls,aged from 1 day to 8 years,with mean age of 3.6 years old,were recruited.Serum samples were tested for CMV IgM,CMV IgG,and CMV IgG avidity index using commercial enzyme-linked immunosorbent assay kits.Results Of the total serum samples from 837 children,690 cases were CMV IgG positive.The overall seroprevalence of CMV IgG was 82.4％,with 83.2％ (427/513 cases) and 81.2％ (263/324 cases) in boys and girls,respectively.There was no significant difference in the seroprevalence of CMV IgG between boys and girls (x2 =0.584,P =0.445).Of the 92 infants less than 6 months old,86 cases were CMV IgG positive,and the positive rate was 93.5％.The prevalence gradually declined in infants after 7 months old,fell to the lowest level of 66.7％ at age of 9 months,and then constantly maintained around 80.0％ from 1 to 8 years old (x2 =15.4,P ＜ 0.001).CMV IgM in 352 serum samples were tested,and 23 (6.5％) cases were CMV IgM positive.The positive rate peaked in infants at age of 2-3 months (7/12 cases,58.3％),then decreased over the age and none of the children older than 6 years were IgM positive (x2 =5.1,P ＜0.001).Furthermore,the CMV IgG avidity index assay was performed in all 23 cases of IgM positive individuals to estimate the primary CMV infection rate.The results showed low avidity index (＜ 30％) in 13 infants,the primary infection rate was 56.5％ (13/23 cases).Most subjects with primary infection (n =7,53.8％) were younger than 1 year old.Conclusions The current seroprevalence of CMV IgG in children in China was around 80.0％,lower than that in adults,and the primary CMV infection mostly occurred before 3 months of age.

Changes of regulatory T cells and T helper cells in peripheral blood and their roles in the severity evaluation in children with asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the changes of CD4+CD25+Foxp3+ regulatory T cells (Treg) and T helper cells (Th1/Th2) in peripheral blood and their roles in the severity evaluation in children with asthma.</p><p><b>METHODS</b>One hundred and fifty children with asthma were classified into acute attack (94 cases) and remission (56 cases) groups according to their clinical features, and the acute attack children were subdivided into mild asthma (54 cases) and severe asthma (40 cases) groups. Fifty healthy children were enrolled as a control group. The levels of CD4+CD25+Foxp3+ Treg, CD4+IFN-γ+ Th1 and CD4+IL-4+ Th2 in peripheral blood were measured by flow cytometer.</p><p><b>RESULTS</b>The mean levels of CD4+CD25+Foxp3+ Treg and the ratio of Th1/Th2 in asthmatic children were lower than those in the control group (P<0.01). The Treg levels and the ratio of Th1/Th2 in the acute attack group were lower than those in the remission group and in the control group (P<0.01). The Treg levels in the severe asthma group were lower than those in the mild asthma group (P<0.01). There was a remarkably negative correlation between Treg levels and the asthma severity (r=-0.737, P<0.01), and the Th1/Th2 ratio was also negatively correlated with the asthma severity (r=-0.615, P<0.01). The Treg levels were positively correlated with the Th1/Th2 ratio (r=0.856, P<0.01).</p><p><b>CONCLUSIONS</b>The Treg levels decrease remarkably and Th subsets imbalance occurs in children with asthma. This suggests that Treg and Th immunity play important roles in the pathogenesis of asthma. The Treg levels and the ratio of Th1/Th2 in peripheral blood may be useful in the evaluation of severity in children with asthma.</p>

Detection of Ampicillin - Resistant Genes and Studies on the Molecular Mechanisms of Ampicillin - Resistant Haemophilus Influenzae / 实用儿科临床杂志

Objective To study the molecular mechanisms of ampicillin- resistant haemophilius influenzae (Hi)in Nanjing. Methods One hundred and fifty- eight strains of Hi isolated from children were collected to detect bata-lactamase. TEM and ROB bata- lacta-mase genes were detected by polymerase chain reaction (PCR) ,and cloned into T vector for sequencing. Results The rate of ampicillin resistance was 41. 77% in Hi isolated from children in Nanjing,40.51 % was found to be bata-lactamase production. Eighty-nine strain were TEM positives, 1 strain was ROB positive,63 strains bata - lactamase positive ampicillin- resistant Hi were identified. The resistance mechanism of ampicillin resistant Hi was production of bata - lactamase , mainly TEM - type enzyme. Two bata - lactamase negative ampicillin - resistant Hi were identified , predicts the other mechanisms of ampicillin - resistant Hi was occuered yet . One strain of non -TEM - type,and non - ROB - type bata - lactamase - producing Hi was identified. Conclusions Ampicillin - resisitant in Hi isolated from children in this region is challenging. TEM bata - lactamase is the principal mechanism of ampicillin - resistant of Hi.