Objective To analyze the epidemiological features of childhood cancer in China, and to provide some clues and basis for related academic research, the formulation of prevention and control strategy, and the construction of prevention and control system of childhood cancer. Methods The data of childhood cancer in children aged 0-14 years which were published in Chinese Cancer Registry Annual Report in 2009-2012 and from GLOBOCAN2012 database were collected. A descriptive statistical analysis was done to determine the distributions of incidence and mortality by time, area, age, and sex. Results In China, the incidence of childhood cancer showed a slight fluctuation with time, while the mortality rate remained stable. The incidence of childhood cancer in China was lower than the world average, and it was much lower than in the United States and Japan. However, the mortality of childhood cancer in China was higher than that in the United States and Japan. The incidence of childhood cancer in Chinese urban areas was about 2 times that in Chinese rural areas, while the mortality in the urban and rural areas was similar. The incidence and the mortality of childhood cancer both declined with increasing age. The incidence and the mortality of childhood cancer in boys were higher than those in girls. Conclusions The incidence and mortality of childhood cancer in China show distribution characteristics by time, area, age, and sex, which can help to make clear the future direction of childhood cancer research and provide some ideas for the comprehensive prevention and control.

Objective To study the correlation between serum insulin-like growth factor-1 (IGF-1) level and feeding difficulties in preterm infants. Methods A retrospective analysis was performed on 200 preterm infants born between January 2013 and January 2014. Venous blood samples were obtained within 24 hours after birth to determine the serum level of IGF-1. The correlation between IGF-1 level and feeding difficulties in preterm infants was analyzed by single-factor analysis and multivariate logistic regression analysis. Results The serum IGF-1 level in the feeding difficulty group was significantly lower than that in the control group (28±4 ng/mL vs 63±8 ng/mL; P<0.05). Results of multivariate logistic regression analysis showed that high gestational age and birth weight were protective factors for feeding difficulties in preterm infants, whereas asphyxia, delayed initiation of feeding, use of aminophylline, perinatal infection and decreased IGF-1 level were risk factors. Conclusions The level of serum IGF-1 is correlated with feeding difficulties in premature infants. A reduced IGF-1 level increases the risk of feeding difficulties.

Objective To study the incidence and risk factors for extrauterine growth retardation (EUGR) at discharge in premature infants. Methods A retrospective analysis was performed on 596 premature infants who were admitted to the neonatal intensive care unit between 2006 and 2010. These subjects were classified into EUGR (n=217) and non-EUGR groups (n=379) based on the body weight at discharge. The risk factors for the occurrence of EUGR were studied by multivariate logistic regression analysis. Results Based on the body weight, length, and head circumference, the incidence of EUGR at discharge was 36.4% (217 cases), 42.0% (250 cases), and 22.8% (136 cases), respectively. Low gestational age, low birth weight, intrauterine growth retardation (IUGR), delayed enteral feeding and complications of the respiratory system were identified as risk factors for EUGR (OR=6.508, 14.522, 5.101, 1.366, and 1.501, respectively). Conclusions The incidence of EUGR might be greatly decreased by strengthening the perinatal care, reducing the incidence of premature delivery and IUGR, undertaking early enteral feeding, and actively preventing postnatal complications.

Objective To study the frequency distribution of single nucleotide polymorphisms (SNPs) in two genes associated with incomplete Kawasaki disease (KD) (rs1569723 in CD40 gene and rs2736340 in BLK gene), and to investigate its association with the genetic susceptibility and clinical phenotypes of incomplete KD. Methods A total of 184 children with incomplete KD and 203 normal children were recruited to carry out a case-control study. The genotypes of SNPs in CD40 gene and BLK gene were determined using polymerase chain reaction-restriction fragment length polymorphism. The frequency distribution of genotypes was compared between the KD and control groups. The association between gene polymorphisms and clinical features of incomplete KD was analyzed. Results There were no significant differences in genotype (AA, AC, CC) and allele frequencies in CD40 SNP rs1569723 between the KD and control groups. There were significant differences in the frequency distribution of three genotypes (TT, CT, CC) in BLK SNP rs2736340 between the KD and control groups (P=0.031), and the KD group had a significantly higher frequency of T allele than the control group (P=0.007). There were significant differences in the incidence of conjunctival hyperaemia among the patients with different genotypes (rs1569723 in CD40 gene) (P=0.036). The SNP rs2736340 in BLK gene was associated with the extremity changes in KD patients (P=0.017). Conclusions The SNP rs2736340 in BLK gene is associated with the susceptibility to incomplete KD, and the SNP rs1569723 in CD40 gene and SNP rs2736340 in BLK gene are associated with some of clinical phenotypes of incomplete KD.

Objective To study the association of single nucleotide polymorphisms (SNPs, rs223895 and rs223899) in TARC/CCL17 gene with Kawasaki disease (KD) and its clinical characteristics in Han children from Central China. Methods A case-control study was performed on 218 children with KD and 248 normal control children. The genotypes of SNPs (rs223895 and rs223899) in TARC/CCL17 gene were determined by polymerase chain reaction-restriction fragment length polymorphism. The association between the SNPs in TARC/CCL17 gene and the clinical characteristics of KD was assessed. Results There were significant differences in the genotype (CC, CT, TT) and allele frequencies of SNP rs223895 between children with KD and controls (P<0.05), and C allele was a risk factor (OR=1.397). However, no significant differences were found between the two groups in the genotype and allele frequencies of SNP rs223899. Compared with those with other genotypes (CT+TT) of SNP rs223895, patients with CC genotype had significantly lower hemoglobin (Hb) and albumin (Alb) levels (P<0.05) and a significantly higher erythrocyte sedimentation rate (ESR) (P <0.05). Conclusions The SNP rs223895 in TARC/CCL17 gene is associated with the susceptibility to KD, and C allele is a risk factor. Moreover, SNP rs223895 may influence the levels of Hb, Alb, and ESR.

Objective To investigate adipokines levels in obese children with acanthosis nigricans (AN) and to explore the relationship between AN and metabolic syndrome (MS). Methods A cross-sectional study was performed on 109 obese children and 47 age-and gender-matched normal controls. The obese children were divided into two groups with AN and without AN. Serum levels of adiponectin, leptin, TNF-α and retinol-binding protein 4 (RBP4) were measured using ELISA. Multiple logistic regression analysis was performed to estimate the association of clinical parameters with MS. Results Waist-hip ratio, systolic blood pressure, triglyceride, fasting insulin and insulin resistance index (HOMA-IR) were significantly higher in obese children with AN than in those without AN and normal controls (P<0.05). The obese children with AN and without AN had lower adiponectin levels than normal controls (P<0.05), on the contrary, the obese children with AN had higher leptin levels than those without AN and normal controls (P<0.05). Multiple logistic regression analysis revealed that AN (OR=3.469, 95%CI: 1.518-7.929) and BMI (OR=7.108, 95%CI: 2.359-21.416) were independent risk factors for MS. Conclusions As a visible marker of insulin resistance, AN is associated with abnormal adipokines secretion. Reducing the incidence of AN and losing weight may prevent obesity associated MS.

Objective To investigate frequency distribution of gene polymorphisms of PRF1 gene in children with hemophagocytic lymphohistiocytosis (HLH), and to explore whether the possible gene polymorphisms of PRF1 gene confer an increased risk of susceptibility to HLH. Methods Forty-eight children who were diagnosed with HLH between January 2009 and December 2013 (HLH group) and 100 healthy children (control group) were enrolled in this study. The gene polymorphisms in the coding region of PRF1 gene, which consists of three exons and two introns, were genotyped by PCR, followed by direct sequencing. Results Three single nucleotide polymorphisms (SNPs) were revealed in the coding sequence of PRF1 in the 48 children with HLH. Seven SNPs were detected in the noncoding sequence. Other two SNPs in the noncoding sequence including rs10999426 and rs10999427 were detected only in 5 healthy children (5%). There was no significant difference in allelic frequencies of all the SNPs above between the HLH and control groups (P>0.05). Haplotype analysis showed there was a pair-wise linkage disequilibrium between rs10999426 and rs10999427 (D=1, r²=1), but there was no significant difference in the distribution of A-T haplotype between the HLH and control groups (P>0.05). Conclusions There is no association between gene polymorphisms of PRF1 gene and the susceptibility to HLH. There is a pair-wise linkage disequilibrium between rs10999426 and rs10999427, but a low detection rate of A-T haplotype in healthy children indicates that it might not play a protective role in the development of HLH.

Objective To study the role of proximal nerve stimulation at Erb point in the early diagnosis of Guillain-Barré syndrome (GBS) in children. Methods Thirty-two children who were diagnosed with GBS between October 2013 and December 2014 received neurophysiological examination. Thirty healthy children were used as controls. Compound muscle action potentials and distal motor latency of the median and ulnar nerves were determined and analyzed after nerve stimulation at the wrist, elbow, and Erb point in the two groups. Moreover, F-wave latency of the median nerve and H-reflex latency of the tibial nerve were measured and analyzed in the two groups. Results The F-wave and H-reflex latencies were significantly longer in the patient group than in the control group (P<0.05). In thirty-two patients, the numbers of patients with abnormal amplitude, abnormal latency, and conduction block at Erb's point were 24 (75%), 22 (69%), and 20 (62%), respectively. The patient group had significantly lower amplitudes but significantly longer latencies of the ulnar and median nerves at Erb point than the control group (P<0.05). There were no significant differences in the amplitudes and latencies at the wrist and elbow between the two groups (P>0.05). Conclusions The nerve stimulation at Erb point holds promise as a routine examination for the early diagnosis of GBS.

Objective To study the changes and significance of lymphocyte sunsets and serum interferon-γ (IFN-γ) levels in children with toxoplasma infection. Methods Thirty-four children who were newly diagnosed with toxoplasma infection (TOX-IgM⁺ group) between January 2011 and April 2014, 12 children who had ever been diagnosed with toxoplasma infection (TOX-IgG⁺ group), and 54 healthy children (control group) were enrolled. The percentages of CD4⁺, CD8⁺, CD19⁺ and NK cells in peripheral blood lymphocytes were detected by flow cytometry. Serum levels of IFN-γ were measured using ELISA. Results The percentages of CD4⁺ cells and the CD4⁺/CD8⁺ ratio in the TOX-IgM⁺ group were significantly lower than in the TOX-IgG⁺ and control groups, while the percentages of CD8⁺ and NK cells and serum IFN-γ levels were significantly higher than in the other two groups (P<0.05). The TOXIgG⁺ group had higher serum IFN-γ levels than the control group (P<0.05). There was a positive correlation between the percentage of CD8⁺ cells and serum IFN-γ levels in the TOX-IgM⁺ group (r=0.756; P<0.05). Conclusions CD4⁺, CD8⁺ and NK cells may play important roles in the resistance against toxoplasma infection by promoting the secretion of cytokines.

Objective To study the changes in pulmonary function and fractional exhaled nitric oxide in exhaled breath (FeNO) in asthmatic children who have different responses to regular treatment. Methods A total of 52 asthmatic children who had a good compliance with regular stepped control treatment were selected as subjects. They were followed up every three months to evaluate the asthma control level, pulmonary ventilation function, and FeNO for 9 months. Besides, medications for asthma control were recorded. Results At three follow-up points (months 3, 6, and 9), the percentage of asthmatic children who used the first or the second level of control treatment in the stable group (with stable response to the treatment) was significantly higher than in the unstable group (with unstable response to the treatment) (P<0.05), while the percentage of asthmatic children who used the third level of control treatment in the stable group was significantly lower than in the unstable group (P<0.05). At the three follow-up points, the stable group had a significantly higher ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) than the unstable group (P<0.05); at the 3-month and 9-month follow-up points, the stable group had a significantly higher percentage of predicted maximum mid-expiratory flow (MMEF%) than the unstable group (P<0.05); at the initial evaluation and 3-month follow-up point, the stable group had a significantly higher FeNO than the unstable group (P<0.05). Conclusions Continuously monitoring FEV1/FVC, MMEF% and FeNO is useful in the early evaluation of the responses to treatment in children with asthma.

Objective To study the clinical characteristics of children with meningitis caused by Streptococcus pneumoniae (SP) and the drug sensitivity of SP strains. Methods A retrospective analysis was performed on the clinical data of 14 children with SP-infected meningitis between September 2008 and March 2014. Results Of the 14 cases, 8 cases (57%) aged under 2 years. 13 cases (93%) had fever, 9 cases (64%) had convulsions, and 7 cases (50%) were complicated by septicemia. Eleven cases (79%) had elevated white blood cell (WBC) counts and 10 cases (71%) had elevated serum C-reactive protein (CRP) levels. All 14 children had an elevated nucleated cell count and neutrophils were identified as the predominant cell type. CSF protein >1 000 mg/dL was noted in 9 cases (64%). Ten cases (71%) were cured, 2 cases (14.2%) with sequelae and 2 cases (14.2%) died. The drug sensitivity analysis showed that SP had resistance rates of more than 60% to penicillin, erythromycin, clindamycin, tetracycline and sulfa, but it was sensitive to amoxicillin (93%), vancomycin (100%), chloramphenicol (100%) and levofloxacin (100%). Conclusions The clinical characteristics of children with meningitis caused by SP are not different from those with meningitis caused by other bacteria. SP strains are resistant to common antibiotics used in clinical practice, so it is important to monitor the drug resistance of the strains.

Objective To study the clinical features, treatment, and prognosis of purulent meningitis (PM) in children. Methods A retrospective analysis was performed on the clinical data of 317 children with PM aged from 1 month to 15 years. Results PM was commonly seen in infants (198 cases, 62.6%). Most children with PM had preceding respiratory infection (171 cases, 53.9%). The major clinical manifestations of PM were fever, convulsions, and intracranial hypertension, and convulsions were more commonly seen in infants (152 cases, 93.6%). The major complication was subdural effusion (95 cases, 29.9%). Of the 95 cases of subdural effusion, 22 cases were diagnosed by subdural puncture; 68 cases underwent subdural puncture and 62 cases restored to normal temperature 3-5 days after puncture. Risk factors associated with complications and sequelae were young age and protein ≥1 g/L in cerebrospinal fluid (CSF) (OR=0.518, 1.524 respectively; P<0.05). The third-generation cephalosporins were the first choice for PM, and vancomycin or carbapenems were replacement therapy. Thirteen (14.4%) out of 90 children had delayed cerebral vasculitis during a follow-up visit within 3 months after discharge. Conclusions PM is more commonly seen in infants, and the infants have a high incidence of convulsions. Young age and protein ≥1 g/L in CSF may increase the risk of complications and sequelae. Subdural puncture is not only a diagnostic method but also a therapy for subdural effusion. Some children have delayed cerebral vasculitis during a follow-up visit within 3 months after discharge, so follow-up visits should be performed within 3 months after discharge.

Objective To investigate the risk factors for attention deficit hyperactivity disorder (ADHD) and to provide a basis for future prevention and treatment of this disease. Methods Following a systematic search for casecontrol studies on the risk factors for ADHD in China between 2000 and 2014, relevant family risk factors were extracted accordingly. The quality of selected studies was evaluated according to the NOS scale. A Meta analysis on the selected studies was conducted using Stata 12.0 software. Results A total of 16 studies were selected, involving 2 167 children with ADHD and 2 148 normal controls. Results of Meta analysis showed that good parenting (OR=0.32, 95% CI: 0.26-0.40), nuclear family (OR=0.56, 95% CI: 0.41-0.76), high education level of father (OR=0.56, 95% CI: 0.41-0.76), high education level of mother (OR=0.65, 95% CI: 0.47-0.89), and extroversion of mother (OR=0.33, 95% CI: 0.18-0.61) are favorable factors for ADHD. Poor parental relationship (OR=1.90, 95% CI: 1.17-3.06) and family history of ADHD (OR=5.86, 95% CI: 3.67-9.35) are risk factors for ADHD. Conclusions Good parenting, nuclear family, high education level of parents, and mother with extroversion are protective factors for ADHD, whereas poor parental relationship and family history of ADHD are associated with an increased risk for ADHD.

Objective To investigate the impacts of biological factors (age and sex) and family factors (socioeconomic status and parenting style) on the early lexical and intellectual development of children in a longitudinal tracking study. Methods A total of 38 Mandarin-speaking children aged from 18 to 24 months were surveyed using the Putonghua Chinese Communicative Development Inventory (PCDI), the Ages and Stages Questionnaire (ASQ), and a self-designed Questionnaire for Parents. All of the subjects were retested using PCDI and ASQ after 6 months. Results Biological factors accounted for 65% of the variance in lexical development, 10% of which was attributed to gender, in the first survey. After six months, the contribution of age decreased to 26% and gender had no significant impact. Lexical development could positively predict the intellectual development of children. When age and gender were controlled, it accounted for 22% of the variance in intellectual development. Family socioeconomic factors had no significant impacts on lexical and intellectual development. Children's recognition of people and objects around them with guidance of parents in parenting styles could positively predict the intellectual development of children six months later, which accounted for 10% of the variance. Conclusions Biological factors play an important role in the early lexical development of children. However, the influence decreases with the increase of age (months). Biological factors, lexical development, and parenting style have a combined influence on children's intellectual development.

Objective To investigate the effects of rapamycin (RAP) on pulmonary hypertension (PH) in rats, and to provide new insights into medication selection for the clinical treatment of PH. Methods Fifty male Sprague-Dawley rats were randomly divided into blank control, PH model, solvent control, RAP 1, and RAP 2 groups. A rat model of PH was induced by left pneumonectomy (PE) and monocrotaline (MCT). At 5 days after PH model establishment, the solvent control group and the RAP 1 group received an intramuscular injection of solvent and RAP, respectively. At 35 days after PH model establishment, the RAP 2 group received an intramuscular injection of RAP. The mean pulmonary artery pressure (mPAP) and the right ventricle/left ventricle plus septum weight ratio (RV/LV+S) were measured in each group. Histopathological changes in the right lung were evaluated by hematoxylin-eosin (HE) staining. The relative expression of alpha-smooth muscle actin (α-SMA) and smooth muscle protein 22-alpha (SM22α) in each group was determined using real-time PCR. Results At 35 days after surgery, the PH model and the solvent control groups had significantly higher mPAP and RV/LV+S than the blank control group, while the RAP 1 and the RAP 2 groups had significantly lower mPAP than the solvent control group (P<0.05). The RV/LV+S in the RAP 1 group was significantly lower than that in the solvent control group (P<0.05); however, there was no significant difference in RV/LV+S between the RAP 2 and the solvent control groups (P>0.05). HE staining in the right lung showed the substantially thickened pulmonary artery wall and narrowed arterial lumen in the PH model and the solvent control groups compared with the blank control group. Different degrees of reversal of the pulmonary artery wall thickening were observed after RAP administration. The results of real-time PCR revealed that the relative expression of α-SMA and SM22α in the PH model and the solvent control groups was significantly lower than in the blank control group, while the relative expression of α-SMA and SM22α in the RAP 1 and the RAP 2 groups was significantly higher than in the solvent control group (P<0.05). Conclusions RAP can reverse the increase in pulmonary artery pressure and the right ventricular hypertrophy probably by regulation of the phenotypic conversion of vascular smooth muscle cells.

Objective To study the effects of umbilical cord monoculcear cells (UCBMC) transplantation combined with hyperbaric oxygen (HBO) therapy on the long-term behaviors and histology in neonatal rats after hypoxic-ischemic brain damage (HIBD). Methods Seven-day-old Sprague-Dawley rats were randomly assigned to four groups: normal control (CON), HIBD, UCBMC and UCBMC+HBO. HIBD was induced according to the Rice-Vannucci method. The rats in the UCBMC+HBO group were treated with HBO 3 hours after HIBD, followed by UCBMC transplantation 24 hours after HIBD. IL-1β and TNF-α protein levels were examined by Western blot analysis in the 4 groups. T-maze test and radial arm maze test were used to detect the long-term learning memory capability. Nissl staining was used to examine the histological changes of the hippocampal CA1 region. Results Twenty-four hours after transplantation, IL-1β and TNF-α protein levels in the UCBMC+HBO group were significantly reduced compared with the HIBD (P<0.01) and UCBMC groups (P<0.05). The study and memory capabilities were impaired, and the number of the pyramidal cells in the hippocampal CA1 region was reduced in the HIBD group. The study and memory capabilities were greatly improved and the number of pyramidal cells increased significantly in the UCBMC+HBO group compared with the UCBMC and HIBD groups (P<0.05). Conclusions UCBMC transplantation combined with HBO therapy could reduce the expression of IL-1β and TNF-α protein, improve long-term behaviors and alleviate brain damages in the hypoxic ischemic neonatal rats.

A 3-year-old boy had abnormal liver function, which was found in physical examination, for 5 months before admission. He had no symptoms such as anorexia, poor appetite, and jaundice, had normal growth and development, and showed no hepatosplenomegaly. Laboratory examination revealed significantly reduced ceruloplasmin (35 mg/L), as well as negative hepatotropic virus, cytomegalovirus, and Epstein-Barr virus. There were normal muscle enzymes, blood glucose, and blood ammonia and negative liver-specific autoantibodies. The boy had negative K-F ring and normal 24-hour urine copper (0.56 μmol/L). The ATP7B gene testing for the boy, his sister, and their parents detected two novel missense mutations in the boy and his sister, i.e., compound heterozygous mutations in exon 7 (c.2075T>C, p.L692P) and exon 13 (c.3044T>C, p.L1015P), which were inherited from their father and mother, respectively. Wilson's disease was confirmed by genetic diagnosis in the boy and his sister. The boy and his sister were given a low-copper diet. The boy was administered with penicillamine for decoppering and zinc supplement against copper uptake. His sister received zinc supplement alone because no clinical symptoms were observed. The boy showed normal liver function in the reexamination after 3 months of treatment.