Objective To study the clinical features of children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods A retrospective analysis was performed for the clinical data of 13 children with SARS-CoV-2 infection who hospitalized in a Changsha hospital. Results All 13 children had the disease onset due to family aggregation. Of the 13 children, 2 had no symptoms, and the other 11 children had the clinical manifestations of fever, cough, pharyngeal discomfort, abdominal pain, diarrhea, convulsions, or vomiting. As for clinical typing, 7 had mild type, 5 had common type, and 1 had severe type. The median duration of fever was 2 days in 6 children. All 13 children had normal levels of peripheral blood lymphocyte counts, immunoglobulins, CD4, CD8, and interleukin-6. The median time to clearance of SARS-CoV-2 was 13 days in the nasopharyngeal swabs of the 13 children. Three children presented false negatives for RT-PCR of SARS-CoV-2. SARS-CoV-2 RNA remained detectable in stools for 12 days after the nasopharyngeal swab test yielded a negative result. Abnormal CT findings were observed in 6 children. All 13 children were cured and discharged and they were normal at 2 weeks after discharge. Conclusions Intra-family contact is the main transmission route of SARS-CoV-2 infection in children, and there is also a possibility of fecal-oral transmission. Mild and common types are the major clinical types in children with SARS-CoV-2 infection, and cytokine storm is not observed. Children with SARS-CoV-2 infection tend to have a good short-term prognosis, and follow-up is needed to observe their long-term prognosis. Multiple nucleic acid tests should be performed for patients with SARS-CoV-2 infection and their close contacts by multiple site sampling.

Objective To study the effect of different antibiotic use strategies on infection in neonates with premature rupture of membranes and the high-risk factors for neonatal infection. Methods A retrospective analysis was performed for the clinical data of 223 neonates with premature rupture of membranes. According to the antibiotic use strategies, they were classified into two groups: study group (n=95) and control group (n=128). The neonates in the study group were given antibiotics based on risk assessment and infection screening, and those in the control group were given antibiotics based on risk assessment alone after admission. General status and prognosis were compared between the two groups. According to the presence or absence of infection, the neonates were classified into two groups: infection group (n=32) and non-infection group (n=191). The clinical data were compared between the two groups. A logistic regression model was used to investigate the high-risk factors for infection in neonates with premature rupture of membranes. Results Compared with the control group, the study group had a significantly longer time of premature rupture of membranes, a significantly higher rate of cesarean section, and a significantly lower antibiotic use rate at admission and a significantly lower total antibiotic use rate (P < 0.05). The study group also had a significantly higher incidence rate of infection and a significantly lower incidence rate of sepsis (P < 0.05). There were no significant differences in the incidence rates of other complications between the two groups (P > 0.05). Compared with the noninfection group, the infection group had a significantly lower gestational age, a significantly longer time of premature rupture of membranes, a significantly higher rate of cesarean section, and significantly higher levels of C-reactive protein (CRP) and procalcitonin on admission and during reexamination (P < 0.05), with fever as the most common symptom. The logistic regression analysis showed that preterm birth and cesarean section were high-risk factors for infection in neonates with premature rupture of membranes (P < 0.05). Conclusions Strict adherence to the indications for antibiotic use in neonates with premature rupture of membranes does not increase the incidence rate of complications. Neonates with premature rupture of membranes, especially preterm infants and infants delivered by cesarean section, should be closely observed for the change in disease conditions, and infection indices including CRP should be reexamined in case of fever and antibiotics should be used to prevent serious infection.

Objective To study the value of procalcitonin (PCT) within 3 days after birth in the diagnosis of neonatal early-onset sepsis (EOS), as well as the thresholds of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. Methods A total of 109 neonates with a confirmed diagnosis of sepsis, 215 neonates with clinically diagnosed sepsis, and 367 neonates without sepsis were enrolled. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. The diagnostic value of PCT and blood culture was compared. Results In the confirmed diagnosis group, the neonates with a gestational age of <34 weeks had a significantly higher level of PCT than those with a gestational age of ≥34 weeks (P < 0.05). For the neonates with a gestational age of ≥34 weeks, the optimal cut-off values of PCT in the diagnosis of EOS were 1.588 ng/mL (sensitivity 0.688, specificity 0.851) at age of <12 hours, 4.960 ng/ mL (sensitivity 0.737, specificity 0.883) at age of 12-<24 hours, 5.583 ng/mL (sensitivity 0.727, specificity 0.865) at age of 24 - <36 hours, 1.710 ng/mL (sensitivity 0.732, specificity 0.755) at age of 36- <48 hours, 3.570 ng/mL (sensitivity 0.488, specificity 0.930) at age of 48-<60 hours, and 3.574 ng/mL (sensitivity 0.333, specificity 0.900) at age of 60-72 hours. PCT had a larger area under the ROC curve in the diagnosis of EOS than blood culture within 36 hours after birth (P < 0.05). Conclusions The same criteria can be used for late preterm infants (with a gestational age of ≥34 weeks) and full-term infants, while early preterm infants (with a gestational age of <34 weeks) should be considered separately. PCT has different optimal cut-off values in the diagnosis of EOS in neonates with different ages, with a higher value than blood culture in the diagnosis of EOS within 36 hours after birth.

Objective To study the association between interleukin-8 (IL-8) rs4073 polymorphisms and susceptibility to sepsis in full-term neonates through a prospective study. Methods A total of 50 neonates who were diagnosed with sepsis based on positive blood culture from January to December 2017 were enrolled as the sepsis group. Fifty neonates who had clinical symptoms and negative blood culture were enrolled as the clinical sepsis group. Fifty neonates without infection were enrolled as the control group. Sequencing was used to detect the polymorphisms of IL-8 rs4073. The three groups were compared in terms of the frequencies of genotypes and alleles. A multivariate logistic regression analysis was used to investigate the association of IL-8 rs4073 genotypes with sepsis in full-term neonates. Results There were significant differences in the frequencies of genotypes and alleles at IL-8 rs4073 among the three groups (P < 0.05). The logistic regression analysis showed that a low gestational age and TT genotype at IL-8 rs4073 were risk factors for the pathogenesis of sepsis in neonates (P < 0.05). Conclusions The full-term neonates with TT genotype at IL-8 rs4073 may be susceptible to sepsis.

Objective To study the clinical features, etiology, treatment, and prognosis of neonatal chylous effusions. Methods A retrospective analysis was performed for the clinical data of 21 neonates with chylous effusions. Results Among these 21 neonates, 13 had chylothorax, 2 had chyloperitoneum, 2 had chylopericardium, and 4 had chylous polyserositis. Five neonates with congenital chylous effusions were enrolled as the congenital group, which mostly occurred in the fetal period, and symptoms were observed shortly after birth. Sixteen neonates with acquired chylous effusions were enrolled as the acquired group, and the symptoms mainly appeared within 1 week after central venous catheterization (in 14 neonates) or appeared together with sepsis (in 2 neonates). Compared with the acquired group, the congenital group had significantly higher specific gravity, white blood cell count, monocyte percentage, and albumin level in effusions (P < 0.05) and significantly lower levels of glucose and triglyceride (P < 0.05). Central venous catheterization-induced chylous effusions were mainly associated with inappropriate position, displacement damage, and hypertonicity. Conservative treatment was the main treatment method for the neonates with chylous effusions (in 20 children), with a response rate of 85%. Compared with the acquired group, the congenital group had a significant higher proportion of neonates receiving special formula feeding, a significantly lower proportion of neonates with extubation, and a significantly longer time to the absorption of effusions (P < 0.05). Conclusions The time to the occurrence of symptoms and clinical manifestations vary with disease etiology and location in neonates with chylous effusions. Neonates with acquired chylous effusions may experience hypertonic solution effusion due to vascular injury. Conservative treatment has a marked clinical effect on neonatal chylous effusions. It appears to be more difficult to treat neonates with congenital chylous effusions than those with acquired chylous effusion.

Objective To study the association of the dynamic changes of peripheral blood human cartilage glycoprotein-39 (YKL-40) and high-mobility group box 1 (HMGB1) with bronchopulmonary dysplasia (BPD) in preterm infants. Methods Preterm infants, with a gestational age of 28-32 weeks and a birth weight of <1 500 g, who were admitted to the neonatal intensive care unit from July 2017 to August 2019 were prospectively selected and divided into a BPD group with 35 infants and a non-BPD group with 51 infants. ELISA was used to measure the serum concentrations of YKL-40 and HMGB1 in preterm infants on days 3, 7, and 14 after birth. Results The BPD group had a significantly lower serum YKL-40 concentration and a significantly higher serum HMGB1 concentration than the nonBPD group on days 3, 7, and 14 (P < 0.001). The serum concentrations of YKL-40 and HMGB1 on days 7 and 14 were significantly higher than those on day 3 in both groups (P < 0.017). In the BPD group, HMGB1 concentration on day 14 was significantly higher than that on day 7 (P < 0.017), while there was no significant change in YKL-40 concentration from day 7 to day 14 (P > 0.017). In the non-BPD group, YKL-40 concentration on day 14 was significantly higher than that on day 7 (P < 0.017), while there was no significant change in HMGB1 concentration from day 7 to day 14 (P > 0.017). Conclusions There are significant differences in the levels of YKL-40 and HMGB1 in peripheral blood between the preterm infants with BPD and those without BPD on days 3, 7, and 14 after birth, suggesting that YKL-40 and HMGB1 might be associated with the development of BPD.

Objective To study the predictive factors for the failure of continuous positive airway pressure (CPAP) treatment in infants with bronchiolitis. Methods A retrospective analysis was performed on the clinical data of 310 hospitalized children (aged 1-12 months) with bronchiolitis treated with CPAP. Their clinical features were compared between the successful treatment group (270 cases) and the failed treatment group (40 cases). A multivariate logistic regression analysis was used to explore the predictive factors for failure of CPAP treatment. Results The multivariate logistic regression analysis showed that the score of the Pediatric Risk of Mortality III (PRISM III) ≥10 (OR=13.905), development of atelectasis (OR=12.080), comorbidity of cardiac insufficiency (OR=7.741), and no improvement in oxygenation index (arterial partial pressure of oxygen/fraction of inhaled oxygen, P/F) after 2 hours of CPAP treatment (OR=34.084) were predictive factors for failure of CPAP treatment for bronchiolitis (P < 0.05). In predicting CPAP treatment failure, no improvement in P/F after 2 hours of CPAP treatment had an area under the receiver operating characteristic curve of 0.793, with a sensitivity of 70.3% and a specificity of 82.4% at a cut-off value of 203. Conclusions No improvement in P/F after 2 hours of CPAP treatment, PRISM III score ≥10, development of atelectasis, and comorbidity of cardiac insufficiency can be used as predictive factors for CPAP treatment failure in infants with bronchiolitis.

Objective To study the short-term effect of two different re-induction regimens in the treatment of acute lymphoblastic leukemia (ALL) children with bone marrow recurrence. Methods A retrospective analysis was performed for 57 ALL children with bone marrow recurrence. According to their treatment regimen, they were divided into two groups: VMDP (vincristine + mitoxantrone + dexamethasone + PEG-asparaginase; n=42) and VIDP (vincristine + idarubicin + dexamethasone + PEG-asparaginase; n=15). The two groups were compared in terms of complete response rate and incidence rate of adverse reactions. Results There was no significant difference in complete response rate between the VMDP and VIDP groups (74% vs 73%, P > 0.05). All children experienced grade ≥3 hematological adverse events. The VMDP group had a significantly lower chemotherapy-related mortality rate than the VIDP group (P < 0.05). There was no significant difference in the incidence rate of infection between the two groups (P > 0.05). Conclusions For ALL children with bone marrow recurrence, both re-induction regimens can achieve a relatively high complete response rate, and VMDP regimen has a lower chemotherapy-related mortality rate and can thus be used as an option for re-induction in ALL children with bone marrow recurrence.

Objective To study the clinical features of central nervous system infiltration-positive (CNSI⁺) children with acute lymphoblastic leukemia (ALL) based on flow cytometry, as well as the association of such clinical features with prognosis. Methods A retrospective analysis was performed for the clinical data of 66 CNSI⁺ children with ALL treated from April 2008 to June 2013. Clinical features, laboratory examination results and prognosis were compared between the children in different chemotherapy stages (induction stage and consolidation/maintenance stage). Results Among the 66 CNSI⁺ children, 50 were in the induction stage and 16 in the consolidation/maintenance stage. Compared with the CNSI⁺ children in the induction stage, the CNSI⁺ children in the consolidation/maintenance stage had a significantly higher proportion of children with the genes associated with good prognosis based on the results of molecular biology (P < 0.05), as well as a significantly higher recurrence rate (P < 0.05). Recurrence was observed in 21 CNSI⁺ ALL children, among whom 10 were in the induction stage and 11 were in the consolidation/maintenance stage. Compared with the children experiencing recurrence in the induction stage, the children experiencing recurrence in the consolidation/maintenance stage had a significantly higher proportion of children with recurrence of the central nervous system and bone marrow (P < 0.05), as well as significantly higher proportion of biochemical positive rate of cerebrospinal fluid (P < 0.05). The children in the induction stage had a significantly higher recurrence-free survival rate than those in the consolidation/maintenance stage (P < 0.001), while there was no significant difference in overall survival rate between the two groups (P > 0.05). Conclusions In children with ALL, CNSI⁺ has a marked effect on recurrencefree survival rate in different chemotherapy stages, but has no obvious effect on overall survival rate. CNSI⁺ patients in the consolidation/maintenance stage have a higher recurrence.

Objective To study the heritability of obesity in children aged 30-36 months in Xi’an, China, as well as the role of four single nucleotide polymorphisms (SNPs) associated with body mass index in the susceptibility to obesity in children. Methods Random sampling was performed to select 1 637 children, aged 30-36 months, from four communities of Xi'an from March 2017 to December 2018. Physical assessment was performed for these children, and a questionnaire survey was conducted for parents. Then the Falconer regression method was used to calculate the heritability of childhood obesity. Venous blood samples were collected from 297 children who underwent biochemical examinations, among whom there were 140 children with obesity/overweight (obesity/overweight group) and 157 with normal body weight (normal body weight group). The MassARRAY RS1000 typing technique was used to detect CDKAL1 gene rs2206734, KLF9 gene rs11142387, PCSK1 gene rs261967, and GP2 gene rs12597579. The distribution of alleles and genotypes was compared between the obesity/overweight and normal body weight groups. An unconditional logistic regression model was used to investigate the benefits of dominant and recessive genetic models. Results For the 1 637 children, the heritability of obesity from the parents was 83%±8%, and the heritability from mother was slightly higher than that from father (86%±11% vs 78%±12%). There were significant differences in the distribution of rs2206734 alleles and genotypes and rs261967 genotypes between the obesity/overweight and normal body weight groups (P < 0.0125). The children carrying T allele at rs2206734 had a significantly higher risk of obesity than those carrying CC (OR=0.24, P < 0.0125), and the children carrying GG at rs261967 had a significantly higher risk of obesity than those carrying A allele (OR=4.11, P < 0.0125). Conclusions Genetic factors play an important role in the pathogenesis of obesity in children, and the SNPs of CDKAL1 rs2206734 and PCSK1 rs261967 are associated with the susceptibility to obesity in children aged 30-36 months in Xi'an.

Objective To study the characteristics of vocalization during the still-face paradigm (SFP) before the age of 2 years and their correlation with the severity of autism spectrum disorder (ASD) symptoms at diagnosis in children with ASD. Methods A total of 43 children aged 7-23 months, who were suspected of ASD, were enrolled as the suspected ASD group, and 37 typical development (TD) children, aged 7-23 months, were enrolled as the TD group. The frequency and durations of vocalization in the SFP were measured. The children in the suspected ASD group were followed up to the age of 2 years, and 34 children were diagnosed with ASD. Autism Diagnostic Observation Schedule (ADOS) was used to assess the severity of symptoms. The correlation of the characteristics of vocalization before the age of 2 years with the severity of ASD symptoms was analyzed. Results Compared with the TD group, the ASD group had significant reductions in the frequency and durations of meaningful vocalization and vocalization towards people and a significant increase in the duration of vocalization toward objects (P < 0.05). The Spearman correlation analysis showed that in the ASD group, the frequency and durations of total vocalization, non-speech vocalization, babbling, vocalization towards people, and vocalization towards objects were negatively correlated with the score of communication in ADOS (P < 0.05). The frequency and durations of total vocalization, babbling, and vocalization towards people and the duration of vocalization towards objects were negatively correlated with the score of reciprocal social interaction in ADOS (P < 0.05). The frequency of total vocalization, the duration of babbling, and the frequency and duration of vocalization towards people were negatively correlated with the score of play in ADOS (P < 0.05). The frequency of total vocalization and non-speech vocalization and the frequency and durations of vocalization towards people were negatively correlated with the score of stereotyped behaviors and restricted interests in ADOS (P < 0.05). The multiple linear regression analysis showed that the frequency of total vocalization was a negative predictive factor for the score of communication in ADOS (P < 0.001), and the duration of vocalization towards people was a negative predictive factor for the score of reciprocal social interaction in ADOS (P < 0.05). Conclusions SFP can better highlight the abnormal vocalization of ASD children before the age of 2 years, and such abnormalities can predict the severity of ASD symptoms early.

Objective To study the association of T-wave amplitude on electrocardiogram (ECG) with left ventricular ejection fraction (LVEF) in children with dilated cardiomyopathy. Methods A retrospective analysis was performed for the clinical data of 44 children who were diagnosed with dilated cardiomyopathy from May 2009 to June 2018. According to LVEF, they were divided into two groups: LVEF ≥50% group (n=26) and LVEF <50% group (n=18). After treatment, 25 children were followed up for 3-42 months (mean 14±9 months). The Guangdong Zhongshan SR-1000A ECG Automatic Analyzer was used to obtain the 12-lead body surface ECG results in the supine position. T-wave amplitude on ECG was evaluated by software and manual measurement. Results Compared with the LVEF ≥50% group, the LVEF <50% group had a significant reduction in the T-wave amplitude in leads II, V₄, V₅ and V₆ (P < 0.05). The increased-LVEF group (an increase in LVEF>5% after treatment) had a significant increase in the T-wave amplitude in leads aVR, V₅, and V₆ after treatment (P < 0.05), while the unchanged-LVEF group (an increase in LVEF ≤ 5% after treatment) had a significant reduction in the T-wave amplitude in lead aVR after treatment (P < 0.05). The receiver operating characteristic curve analysis showed that the T-wave amplitude in leads II, V₄, V₅ and V₆ had a certain value in predicting LVEF <50% in children with dilated cardiomyopathy (P < 0.05). A combination of T-wave amplitude of ≤0.20 mV in lead II, ≤0.40 mV in lead V₄, and ≤0.30 mV in leads V₅ and V₆ had a sensitivity of 88.2% and specificity of 76.0% in the predication of LVEF <50% in children with dilated cardiomyopathy. Conclusions T-wave amplitude on ECG can be used as the indexes for the evaluation of the left ventricular systolic function in children with dilated cardio myopathy.