Feeding intolerance (FI) is one of the most common clinical problems in preterm infant and often leads to the delay in reaching total enteral nutrition and prolonged hospital stay. The prevention and treatment of FI are of great significance in improving the survival rate of preterm infants. With reference to current evidence in China and overseas, the clinical guidelines for the diagnosis and treatment of FI in preterm infants were developed based on Grading of Recommendations Assessment, Development and Evaluation (GRADE), so as to help neonatal pediatricians, nursing staff, and nutritionists with early identification and standard management of FI in preterm infants.

Neonatal capillary leak syndrome is a clinical syndrome with definite etiology or predisposing factors and has the manifestations of hypotension, hemoconcentration, hypoproteinemia, and systemic edema. This disease often has critical conditions and may lead to multiple organ failure and even death. There are still controversies over the diagnosis and treatment of this disease. This article summarizes the recent advances in the diagnosis and treatment of neonatal capillary leak syndrome, in order to improve the diagnosis and treatment of this disease among clinicians.

Objective To study the effect of different vitamin D supplementation regimens on the nutritional status of vitamin D on day 28 after birth in preterm infants with a gestational age of < 34 weeks. Methods A total of 59 preterm infants with a gestational age of < 34 weeks who were born from October 2018 to October 2019 were enrolled and divided into an observation group with 30 infants and a control group with 29 infants. The infants in the observation group received a single-dose intramuscular injection of vitamin D₃ (10 000 IU/kg), while those in the control group received oral vitamin D₃ drops (900 IU/d) for 25 days. Venous blood samples were collected within 48 hours after birth (before vitamin D₃ supplementation) and on day 28 after birth to measure the serum 25-hydroxyvitamin D[25(OH)D] level. Results Within 48 hours after birth, the prevalence rate of vitamin D deficiency (≤ 15 ng/mL) was 78% among the 59 preterm infants. There were no significant differences in the serum 25(OH)D level and the prevalence rate of vitamin D deficiency between the two groups (P > 0.05). Compared with the control group on day 28 after birth, the observation group had a significantly higher serum 25(OH)D level (P < 0.05) and a significantly lower prevalence rate of vitamin D deficiency (P < 0.05). There were no cases of vitamin D overdose or poisoning. Conclusions In preterm infants with a gestational age of < 34 weeks, single-dose intramuscular injection of 10 000 IU/kg vitamin D₃ can significantly increase serum 25(OH)D level on day 28 after birth and safely and effectively reduce the prevalence rate of vitamin D deficiency.

Objective To study the value of quantitative electroencephalography (qEEG) in evaluating the effect of blood glucose on the brain function of preterm infants. Methods The preterm infants who were admitted to the Department of Neonatology, The Third Xiangya Hospital of Central South University, from January to December 2019 were enrolled. According to the level of blood glucose, they were divided into group 1 (blood glucose < 4.95 mmol/L), group 2 (blood glucose 4.95 to < 6.60 mmol/L), group 3 (blood glucose 6.60 to < 8.55 mmol/L), and group 4 (blood glucose ≥ 8.55 mmol/L). The changes in qEEG parameters were compared between groups, and a correlation analysis was performed for blood glucose and qEEG parameters. Results A total of 39 preterm infants were enrolled (84 blood glucose measurements). Compared with group 4, the other three groups had significant increases in the total spectral power of each brain region and the absolute power of each frequency band in the frontal and occipital regions (P < 0.05). The total spectral power, δ/θ ratio, and (δ + θ)/(α + β) ratio of each brain region were negatively correlated with blood glucose level, while the relative power of θ frequency band was positively correlated with blood glucose level (P < 0.05). Conclusions With the change in blood glucose, there are significant changes in the total spectral power of each brain region, the power of each frequency band, and the frequency spectrum composition on qEEG in preterm infants. qEEG may therefore become an important tool to monitor the effect of abnormal blood glucose on brain function in preterm infants.

Objective To study the risk factors and treatment outcome of hypothyroidism in very low birth weight/extremely low birth weight (VLBW/ELBW) infants. Methods The VLBW/ELBW infants who were diagnosed with hypothyroidism from September 2018 to December 2019 were enrolled as the case group (n=29). The children with normal thyroid function, matched at a ratio of 1:3, were enrolled as the control group (n=87). Clinical features were compared between the two groups. The correlation of thyroid function with gestational age and birth weight and the risk factors for hypothyroidism were analyzed. Results A total of 162 VLBW/ELBW infants who met the inclusion criteria were enrolled, with 29 infants in the case group (an incidence rate of hypothyroidism of 17.9%). The lower the birth weight, the higher the incidence rate of hypothyroidism (P < 0.05). Triiodothyronine (T3) and free T3 were positively correlated with gestational age (P < 0.05). T3 and free thyroxine were positively correlated with birth weight (P < 0.05). Small for gestational age, multiple birth, maternal age ≥ 35 years, and use of dopamine were independent risk factors for hypothyroidism (P < 0.05). In the case group, 16 infants were treated with levothyroxine (5-10 μg/kg daily), and the thyroid function returned to normal after 2 weeks of treatment. Conclusions There is a high incidence rate of hypothyroidism in VLBW/ELBW infants. Small for gestational age, multiple birth, advanced maternal age, and use of dopamine are risk factors for hypothyroidism. The infants treated with levothyroxine should be followed up regularly to ensure an appropriate dose.

Objective To assess white matter development in preterm infants with bronchopulmonary dysplasia (BPD) using fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of diffusion tensor imaging (DTI). Methods Ninety-six infants with a gestational age of ≤ 32 weeks and a birth weight of < 1 500 g who were admitted to the neonatal intensive care unit within 24 hours after birth from August 2016 to April 2019 and underwent head MRI and DTI before discharge were enrolled. According to the discharge diagnosis, they were divided into BPD group with 48 infants and non-BPD group with 48 infants. The two groups were compared in terms of FA and ADC values of the same regions of interest on DTI image. Results There were no significant differences in the incidence rates of periventricular/intraventricular hemorrhage, periventricular leukomalacia, and punctate white matter lesions between the two groups (P > 0.05). Compared with the non-BPD group, the BPD group had significantly lower FA values and significantly higher ADC values of the posterior limb of the internal capsule, the splenium of the corpus callosum, the occipital white matter, the cerebellum, and the cerebral peduncle (P < 0.05). Compared with the non-BPD group, the BPD group had a significantly higher frequency of apnea, a significantly higher proportion of infants with pneumonia or mechanical ventilation, and a significantly longer duration of assisted ventilation (P < 0.05). Conclusions BPD may has potential adverse effects to white matter development in preterm infants, leading to delayed white matter development. Therefore, it is necessary to pay attention to the neurological function of these infants.

Objective To study the duration of automated auditory brainstem response (AABR) test for initial hearing screening and the factors influencing the duration in neonates. Methods A total of 472 neonates who were admitted to the neonatal intensive care unit (NICU) were enrolled as the study group and 182 healthy neonates were enrolled as the healthy control group. The influence of the duration of AABR test on the initial screening results was observed in the two groups. The influencing factors for the AABR test duration were analyzed. Results In the AABR screening of 180, 360, and 540 seconds, the study group had a failure rate of 41.5%, 28.4%, and 24.4% respectively, while the healthy control group had a failure rate of 31.3%, 19.8%, and 15.4% respectively, showing a decreasing trend with the extension of test time in both groups (P < 0.05). In the two groups, the screening results of 180-second testing were moderately consistent with those of 360- or 540-second testing (Kappa<0.75, P < 0.05), and the screening results of 360-second testing were highly consistent with those of 540-second testing (Kappa>0.75, P < 0.05). In the study group, the median duration of AABR test was 108 seconds (95%CI:97-120 seconds), which was significantly longer than the duration of 75 seconds (95%CI:65-85 seconds) in the healthy control group (P < 0.05). The Cox regression analysis showed that maternal age ≥ 35 years, anemia, and electrolyte disturbance (RR < 1, P < 0.05) were independent risk factors for prolonged AABR test duration, while the prolonged continuous positive airway pressure-assisted ventilation was a protective factor (RR > 1, P < 0.05). Conclusions The AABR test time of 360-540 seconds for initial hearing screening helps to reduce false positive results due to environmental and risk factors in neonates. It may be useful to reduce the false positive results of AABR screening before discharge by taking corresponding intervention measures for NICU neonates with high risk factors.

Objective To study the association of maternal diabetes mellitus (DM), uncoupling protein 2 (UCP2) gene polymorphisms, and their interaction with the risk of congenital heart disease (CHD) in offspring. Methods A hospital-based case-control study was conducted. A total of 464 mothers of children with CHD alone who were diagnosed in Hunan Children's Hospital from March 2018 to August 2019 were enrolled as the case group. A total of 504 mothers of healthy children who were hospitalized during the same period and did not have any deformity were enrolled as the control group. A questionnaire survey was performed to collect the information on exposure. Venous blood samples (5 mL) were collected from the mothers to detect UCP2 gene polymorphisms. A multivariate logistic regression analysis was used to investigate the association of maternal DM, UCP2 gene polymorphisms, and their interaction with CHD in offspring. Results After control for confounding factors, the multivariate logistic regression analysis showed that mothers with gestational DM (OR=2.96, 95%CI:1.57-5.59), a history of gestational DM (OR=3.16, 95%CI:1.59-6.28), and pregestational DM (OR=4.52, 95%CI:2.41-8.50) significantly increased the risk of CHD in offspring (P < 0.05). The polymorphisms of the UCP2 gene at rs659366 (T/C vs C/C:OR=1.49, 95%CI:1.02-2.16; T/T vs C/C:OR=2.77, 95%CI:1.67-4.62) and rs660339 (A/A vs G/G:OR=2.19, 95%CI:1.34-3.58) were significantly associated with risk of CHD in offspring (P < 0.05). The interaction analysis showed an interaction between the polymorphisms of the UCP2 gene at rs659366 and rs660339 and maternal DM in the development of CHD (P < 0.05). Conclusions Maternal DM, UCP2 gene polymorphisms, and their interaction are associated with the development of CHD in offspring.

Objective To study the effect of the application timing of vasoactive agents on the prognosis of children in the third stage of hand-foot-mouth disease (HFMD). Methods A retrospective analysis was performed on the medical data of children in the third stage of HFMD between April 2012 and September 2016. According to the application time of vasoactive agents (milrinone combined with phentolamine) after admission, the children were divided into an early stage (within 2 hours after admission) group with 32 children, a middle stage (within 2-6 hours after admission) group with 28 children, and a late stage (more than 6 hours after admission) group with 26 children. Venous blood samples were collected before vasoactive agent treatment and after 24 hours of vasoactive agent treatment to measure the levels of creatine kinase-MB (CK-MB), troponin (TnI), and brain natriuretic peptide (BNP). The recovery time of left ventricular ejection fraction (LVEF), respiratory rate, blood pressure, and heart rate were recorded. The response rate to the treatment within 72 hours of treatment was evaluated. Results The early stage group had a significantly higher overall response rate to the treatment than the middle stage and late stage groups (P < 0.0167). After 24 hours of treatment, there were significant differences in heart rate, blood pressure, respiratory rate, and LVEF among the three groups (P < 0.05). The early stage group showed the most significant improvement in these parameters (P < 0.0167). Compared with the middle stage and late stage groups, the early stage group had significantly shorter recovery time of LVEF, respiratory rate, heart rate, and blood pressure (P < 0.0167). After 24 hours of treatment, the early stage group had a significantly lower level of BNP than the middle stage and late stage groups (P < 0.05). Conclusions Vasoactive agents should be given to children with critical HFMD as early as possible to improve cardiovascular function, reduce the risk of disease progression, and improve prognosis.

Objective To study the clinical features of children with influenza and plastic bronchitis (PB). Methods A retrospective analysis was performed on the medical data of 63 children with influenza and PB, including clinical manifestations, laboratory examination results, imaging findings, treatment, and outcome. Results Among the 63 children, there were 52 boys (83%) and 11 girls (17%), and 42 children had influenza A and 21 had influenza B. Among these children, 38 (60%) aged 3-6 years, and 15 (24%) had underlying diseases. The main clinical manifestations were high fever (90%), cough (95%), and shortness of breath (73%). Twenty-four children (38%) were found to have atelectasis by imaging examination. Auscultation showed that 16 children (25%) had no rales in the lungs. Of all children, 41 were admitted to the intensive care unit, and 32 required mechanical ventilation. All children underwent fiberoptic bronchoscopy and alveolar lavage. Among the 63 children, 60 recovered and 3 died. Conclusions Influenza with PB is often observed in boys and preschool children. For influenza children with shortness of breath, even if there is no atelectasis on chest X-ray or no rales are found by auscultation, the possibility of PB still needs to be considered.

Objective To study the role of blood purification in the treatment of severe adenovirus pneumonia. Methods A total of 57 children with severe adenovirus pneumonia who underwent mechanical ventilation from February to June, 2019, were enrolled. According to whether blood purification was performed, they were divided into a purification group with 22 children and a conventional group with 35 children. Related clinical indices were collected, including duration of fever, duration of mechanical ventilation, length of stay in the intensive care unit (ICU), and mortality rate. The purification group was analyzed in terms of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) before blood purification and at 48 hours after blood purification, as well as stroke volume variation (SVV), thoracic fluid content (TFC), arterial partial pressure of oxygen/fraction of inhaled oxygen (P/F) value, and partial pressure of carbon dioxide (PCO2) before blood purification and at 6, 12, 24, and 48 hours after blood purification. Results Compared with the conventional group, the purification group had significantly shorter duration of fever, duration of mechanical ventilation, and length of stay in the ICU (P < 0.05), and there was no significant difference in the mortality rate between the two groups (P > 0.05). The purification group had significant reductions in IL-6 and TNF-α after blood purification, (P < 0.05) and significant reductions in SVV and TFC at 12, 24, and 48 hours after blood purification (P < 0.01), as well as a significant increase in P/F value and a significant reduction in PCO2 at 6, 12, 24, and 48 hours after blood purification (P < 0.01). Conclusions Blood purification as an auxiliary therapy can effectively improve the clinical symptoms of children with severe adenovirus pneumonia, and is thus an option for the treatment of severe adenovirus pneumonia in children.

This article reports the clinical and genetic features of a case of Tatton-Brown-Rahman syndrome (TBRS) caused by DNMT3A gene mutation. A girl, aged 8 months and 14 days, had the clinical manifestations of psychomotor retardation, hypotonia, ventricular enlargement, and tonsillar hernia malformation. Gene analysis identified a novel heterozygous mutation, c.134C > T(p.A45V), in the DNMT3A gene, and the wild type was observed at this locus in her parents. This mutation was determined as a possible pathogenic mutation according to the guidelines of American College of Medical Genetics and Genomics, which had not been reported in previous studies and conformed to autosomal dominant inheritance. This child was diagnosed with TBRS. TBRS often has a good prognosis, with overgrowth and mental retardation as the most common clinical manifestations, and behavioral and psychiatric problems, scoliosis, and afebrile seizures are possible complications of TBRS. The possibility of TBRS should be considered for children with overgrowth and mental retardation, and genetic diagnosis should be conducted when necessary.

Objective To study the expression of angiotensin-converting enzyme 2 (ACE2) and other key molecules of the RAS pathway in normal mice at different developmental stages, and to provide ideas for understanding the infection mechanism of coronavirus disease 2019 (COVID-19) as well as the diagnosis and treatment of children with COVID-19. Methods The mice at different developmental stages were enrolled, including fetal mice (embryonic days 14.5 and 18.5), neonatal mice (0, 3, 7, 14, and 21 days old), young mice (28 and 42 days old), and adult mice (84 days old). The lung tissues of all fetal mice from 4 pregnant mice were collected at each time point in the fetal group. Four mice were sampled in other age groups at each time point. Whole transcriptome resequencing was used to measure the mRNA expression of AGT, ACE, ACE2, Renin, Agtr1a, Agtr1b, Agtr2, and Mas1 in mouse lung tissue. Results The expression of ACE2 in the lungs showed changes from embryonic stage to adult stage. It increased gradually after birth, reached a peak on day 3 after birth, and reached a nadir on day 14 after birth (P < 0.05). The expression of AGT reached a peak on days 0 and 7 after birth and reached a nadir on day 21 after birth (P < 0.05). The expression of ACE increased rapidly after birth and reached a peak on day 21 after birth (P < 0.05). Agtr1a expression reached a peak on day 21 after birth (P < 0.05). Agtr2 expression gradually decreased to a low level after birth. Renin, Agtr1b, and Mas1 showed low expression in lung tissues at all developmental stages. Conclusions At different developmental stages of mice, ACE2 has dynamic expression changes, with high expression in early neonatal and adult mice. The other key molecules of the RAS pathway have their own expression patterns. These suggest that the difference in clinical features between children and adults with COVID-19 might be associated with the different expression levels of ACE2 in the different stages, and further studies are needed for the mechanism.

Objective To study the continuous expression and potential function of circular RNA (circRNA), circ4:150439343|150477468 and circ15:73330849|73343359, in mouse lung development. Methods According to the stage of lung development, lung tissue samples were collected from mice on embryonic day 16.5 (E16.5), embryonic day 18.5 (E18.5), and postnatal day 2 (P2). Hematoxylin and eosin staining was performed to observe the morphology of lung tissue. Quantitative real-time PCR (qRT-PCR) was used to measure the mRNA expression of circ4:150439343|150477468 and circ15:73330849|73343359 during late lung development; miRanda and TargetScan were used to predict the target miRNAs of circRNAs, and then GO and KEGG analysis was performed for the target genes to predict the potential function of circRNAs. Results Type Ⅱ alveolar epithelial cells were observed in the lung slices of E16.5 mice, with a gradual increase in number. On P2, the pulmonary alveoli expanded rapidly, the pulmonary interstitium became thinner, and the alveolar structure gradually became mature. The results of qRT-PCR showed that the relative expression of circ4:150439343|150477468 was continuously upregulated over time and the relative expression of circ15:73330849|73343359 was first downregulated and then upregulated (P < 0.05). The KEGG and GO analysis showed that circRNAs were involved in the Notch, PI3K-Akt, and NF-κB signaling pathways. Conclusions Circ4:150439343|150477468 and circ15:73330849|73343359 can participate in lung development through the Notch signaling pathway.

A boy, aged 6 months, had the manifestations of intellectual and motor developmental delay, head instability, general weakness, unawareness of grasping objects by hands, and unusual facies (slightly wide eye distance, epicanthus, esotropia, mouth-opening appearance, short philtrum, and low-set ears). Gene detection results showed a de novo heterozygous frameshift mutation of the CHAMP1 gene at the chromosomal location of chr13:115089847, and nuclear acid was changed to c.530delCinsTTT, resulting in a change in amino acid to p.S177Ffs^*2. Therefore, the boy was diagnosed with autosomal dominant intellectual disability-40 caused by the mutation in the CHAMP1 gene. This case report suggests that for children with unexplained intellectual disability, especially those with generalized hypotonia and severe language disorder, the possibility of CHAMP1 gene mutation should be considered, and genetic testing should be performed as early as possible.

A boy, aged 1 month, attended the hospital due to feeding difficulty and hypotonia. He had unusual facial features (prominent forehead, hypertelorism, ptosis of the lateral canthus, thin upper lip, and low-set ears), hypotonia, and a decreased score of neonatal behavioral neurological assessment. Heart ultrasound showed atrial septal defect. Cranial MRI showed widened supratentorial ventricle, cerebral cistern, and subarachnoid space. High-throughput whole-exome sequencing of the boy detected a hemizygous mutation, c.315_320delTGAGCG, in the CCDC22 gene, which came from his mother, while such mutation was not found in his father. The unusual facies, clinical manifestations, and inheritance pattern of this boy were consistent with the manifestations of Ritscher-Schinzel syndrome reported abroad. This is a report for the first time of a case of X-linked recessive Ritscher-Schinzel syndrome caused by the hemizygous mutation c.315_320delTGAGCG in the CCDC22 gene in Chinese population.

Gene panel and whole exome sequencing are now commonly used to detect Mendelian disease, but the current molecular diagnostic rate of DNA sequencing is only 35%-50%. In recent years, RNA sequencing emerges as a promising diagnostic method. It can detect new pathogenic mutations, and analyze allele-specific expression. This will be helpful to understand the relationship between disease genotype and phenotype, and can complement genome sequencing in order to expand the traditional genomic diagnostic methods of Mendelian disease. RNA sequencing is expected to become a routine tool for diagnosing Mendelian diseases. This article reviews the application of RNA sequencing in the clinical diagnosis of Mendelian disease.