No abstract available

Objective To investigate the risk factors for brain injury in preterm infants by a multicenter epidemiological investigation of brain injury in hospitalized preterm infants in Anhui, China. Methods Preterm infants who were hospitalized in the department of neonatology in 9 hospitals of Anhui Neonatal Collaboration Network between January 2016 and January 2017 were enrolled as subjects. The data of maternal pregnancy and clinical data of preterm infants were collected, and the logistic regression model was used to analyze the risk factors for brain injury in preterm infants. Results A total of 3 378 preterm infants were enrolled. Of the 3 378 preterm infants, 798 (23.56%) had periventricular-intraventricular hemorrhage (PVH-IVH), and 88 (2.60%) had periventricular leukomalacia (PVL). Intrauterine distress, anemia, hypoglycemia and necrotizing enterocolitis (NEC) were risk factors for PVH-IVH (OR=1.310, 1.591, 1.835, and 3.310 respectively; P < 0.05), while a higher gestational age was a protective factor against PVH-IVH (OR=0.671, P < 0.05). PVH-IVH, NEC and mechanical ventilation were risk factors for PVL (OR=4.017, 3.018, and 2.166 respectively; P < 0.05), and female sex and use of pulmonary surfactant were protective factors against PVL (OR=0.514 and 0.418 respectively; P < 0.05). Conclusions Asphyxia/anoxia, infection/inflammation, mechanical ventilation, anemia and hypoglycemia may increase the risk of brain injury in preterm infants.

Objective To study the correlation between coagulation function and gestational age in preterm infants and the possible value of coagulation function measurement in predicting hemorrhagic diseases. Methods The clinical data of preterm infants who were hospitalized between September 2016 and August 2017 were collected. The coagulation indicators were measured within 2 hours after birth. According to the gestational age, the preterm infants were divided into late preterm infant group (n=322), early preterm infant group (n=241) and extremely/very early preterm infant group (n=128). Coagulation function was compared among the three groups, as well as between the preterm infants with and without hemorrhagic diseases within 3 days after birth. Results There were significant differences in thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen degradation product (FDP) and D-dimer (DD) among the three groups (P < 0.05). APTT, PT, FDP and DD were negatively correlated with gestational age, while TT was positively correlated with gestational age (P < 0.05). The preterm infants with hemorrhagic diseases had a longer APTT and a higher level of DD (P < 0.05). Conclusions Coagulation function gradually becomes mature in preterm infants with the increase in gestational age. Abnormal APTT and DD indicate that preterm infants may have a higher risk of hemorrhagic diseases.

Objective To study the association between the expression of the MDR3 gene and the pathogenesis of parenteral nutrition-associated cholestasis (PNAC) in preterm infants. Methods Among the preterm infants who were admitted to the hospital from June 2011 to November 2017 and received parenteral nutrition for more than 14 days, 80 who did not develop PNAC were enrolled as non-PNAC group, and 76 who developed PNAC were enrolled as PNAC group. On days 1, 14, 30, 60 and 90 after birth, serum hepatobiliary biochemical parameters[alanine aminotransferase (ALT), total bilirubin (TBil), direct bilirubin (DBil), total bile acid (TBA) and gamma-glutamyl transpeptidase (γ-GT)], fibrosis indices[hyaluronic acid, laminin, procollagen Ⅲ N-terminal peptide and type IV collagen] and clinical manifestations were observed. Real-time quantitative PCR was used to measure the mRNA expression of MDR3 in both groups, and the correlation between the mRNA expression of MDR3 and serum hepatobiliary biochemical parameters was analyzed. Results In the PNAC group, serum levels of hepatobiliary biochemical parameters and fibrosis indices increased on day 14 after birth and reached the peak on day 30 after birth, followed by a reduction on day 60 after birth. On days 14, 30, 60 and 90 after birth, the PNAC group had significantly higher serum levels of hepatobiliary biochemical parameters and fibrosis indices than the non-PNAC group (P < 0.05). The PNAC group had higher relative mRNA expression of MDR3 in peripheral blood cells than the non-PNAC group (P < 0.05). In the PNAC group, the relative mRNA expression of MDR3 in peripheral blood cells was negatively correlated with serum levels of hepatobiliary biochemical parameters (ALT, TBil, DBil, TBA and γ-GT) (P < 0.001). Conclusions High mRNA expression of MDR3 in preterm infants may be associated with the development of PNAC, and further studies are needed to identify the mechanism.

Objective To study the expression of high-mobility group box 1 (HMGB1) in neonates with sepsis and its role in the pathogenesis of neonatal sepsis. Methods A total of 62 neonates with sepsis were enrolled as the sepsis group, 66 neonates with local infection were enrolled as the local infection group, and 70 healthy neonates were enrolled as the healthy control group. Serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-17 (IL-17), interleukin-23 (IL-23), C-reactive protein (CRP) and procalcitonin (PCT) were measured. The mRNA expression of HMGB1, Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) and the protein expression of TLR4 and NF-κB in peripheral blood mononuclear cells (PBMCs) were also measured. PBMCs from healthy neonates were divided into 4 groups:control, HMGB1 treatment, HMGB1+TAK-242 (a TLR4 inhibitor) treatment and HMGB1+PDTC (an NF-κB inhibitor) treatment, and the mRNA expression of TLR4, NF-κB and IL-8 and the protein expression of TLR4 and NF-κB were measured. PBMCs from healthy neonates were divided into another 3 groups:control, LPS treatment and LPS+glycyrrhizin (an HMGB1 inhibitor) treatment, and the mRNA expression of HMGB1, TLR4, NF-κB and IL-8 and the protein expression of TLR4 and NF-κB were measured. Results Compared with the local infection and healthy control groups, the sepsis group had significantly higher serum levels of IL-6, IL-8, IL-17, IL-23, CRP and PCT (P < 0.05), as well as significantly higher mRNA expression of HMGB1, TLR4 and NF-κB and protein expression of TLR4 and NF-κB in PBMCs (P < 0.05). HMGB1 significantly induced the mRNA and protein expression of TLR4 and NF-κB in PBMCs (P < 0.05). TAK-242 inhibited the mRNA and protein expression of TLR4 and NF-κB and mRNA expression of IL-8 (P < 0.05). PDTC inhibited the mRNA and protein expression of NF-κB and the mRNA expression of IL-8 (P < 0.05). LPS significantly induced the mRNA expression of HMGB1 and the mRNA and protein expression of TLR4 and NF-κB and then stimulated the mRNA expression of IL-8 (P < 0.05). Glycyrrhizin inhibited the mRNA expression of HMGB1 and the mRNA and protein expression of TLR4 and NF-κB and then reduced the mRNA expression of IL-8 (P < 0.05). Conclusions HMGB1 plays an important role in the pathogenesis of neonatal sepsis by activating the TLR4/NF-κB signaling pathway and inducing the secretion of inflammatory factors including IL-8. The HMGB1 blocker glycyrrhizin can inhibit activation of the TLR4/NF-κB signaling pathway and the secretion of inflammatory factors.

Objective To investigate the molecular epidemiological characteristics of norovirus (NoV) among children with acute gastroenteritis in Tianjin in 2017. Methods A total of 758 stool specimens were collected from the children with acute gastroenteritis possibly caused by viral infection in Tianjin Children's Hospital between January and December, 2017. Quantitative real-time RT-PCR was used for primary screening of NoV, and conventional RTPCR was used for gene amplification, sequencing and genotype identification of the VP1 region of capsid protein in positive specimens. Results Among the 758 specimens, 241 (31.8%) were found to have GⅡ NoV. Sequencing of the VP1 region of capsid protein in positive specimens showed that among the 241 specimens with GⅡ NoV, 69 (28.6%) had GⅡ.4 subtype, 51 (21.2%) had GⅡ.3 subtype, 24 (10.0%) had GⅡ.2 subtype, and 18 (7.5%) had other subtypes. There was a significant difference in NoV detection rate between different age groups (P=0.018), and the 1- < 4 years group had the highest NoV detection rate (37.3%). There was also a significant difference in NoV detection rate across seasons (P < 0.001), and there was a highest NoV detection rate in winter (48.1%). Twenty-seven children (3.6%) had co-infections with NoV and rotavirus. Conclusions NoV is one of the major pathogens of the children with acute gastroenteritis from Tianjin in 2017. GⅡ genotype, especially GⅡ.4 subtype, is the prevalent strain. NoV infection is commonly seen in children less than 4 years and reaches the peak in winter. Some children are found to have co-infections with rotavirus.

Objective To study the features of pathogens in children with lower respiratory tract infection. Methods A total of 108 children who were hospitalized due to lower respiratory tract infection and underwent fiber bronchoscopy between January 2017 and June 2018 were enrolled. Bronchoalveolar lavage fluid samples were collected. Multiple quantitative real-time PCR was performed to detect pathogens. Results Of the108 children, 85 (78.7%) were found to have pathogens, among whom 52 (48.1%) had single pathogen infection and 33 (30.6%) had multiple pathogen infections. Mycoplasma pneumoniae was detected in 38 children (35.2%), and was the most common pathogen. The children aged 36 - < 72 months had the highest detection rate of Mycoplasma pneumoniae. Both Streptococcus pneumoniae and Haemophilus influenzae were detected in 29 children (26.9%) and Streptococcus pneumoniae was mainly detected in children aged < 24 months. Each of Acinetobacter baumannii, Candida albicans and Klebsiella pneumoniae was detected in 3 children. Among the 31 children with bronchopneumonia, 9 were found to have Haemophilus influenza, with the highest detection rate of 29%. Among the 34 children with lobar pneumonia, 22 were found to have Mycoplasma pneumoniae, with the highest detection rate of 65%. Among the 22 children with bronchial foreign bodies and bronchopneumonia, 10 were found to have Streptococcus pneumoniae, with the highest detection rate of 45%. Conclusions In children with lower respiratory tract infection, Mycoplasma pneumoniae is the most common pathogen, followed by Streptococcus pneumoniae and Haemophilus influenzae. There are differences in the detection rates of pathogens between children with different ages and different types of lower respiratory tract infection.

Objective To study the correlation of galectin-3 level in bronchoalveolar lavage fluid (BALF) with Mycoplasma pneumoniae (MP) load and cellular immunity of neutrophils and macrophages in the airway in children with refractory MP pneumonia (RMPP). Methods A total of 64 children with RMPP who were hospitalized from January 2013 to January 2017 were enrolled. In addition to the conservative medical treatment, all the 64 children with RMPP were given bronchoalveolar lavage in the acute stage (5-7 days after admission) and 48 out of the 64 children were given bronchoalveolar lavage in the recovery stage (10-14 days after admission). Four milliliters of BALF of the affected lung lobe or segment were collected. ELISA was used to measure the level of galectin-3 in BALF supernatant. RT-PCR was used to measure MP load. Hematoxylin and eosin staining was used to measure the percentage of neutrophils and macrophages. Six children with bronchial foreign bodies were enrolled as the control group. Results The RMPP group had a significantly higher level of galectin-3 in BALF in both the acute and recovery stages than the control group (P < 0.01), and the level of galectin-3 in the acute stage was significantly higher than in the recovery stage (P < 0.01). The RMPP group had a significantly higher percentage of neutrophils in BALF in both the acute and recovery stages than the control group (P < 0.01), and the percentage of neutrophils in the acute stage was significantly higher than in the recovery stage (P < 0.01). The RMPP group had a significantly lower percentage of macrophages in BALF in both the acute and recovery stages than the control group (P < 0.01), but there was no significant difference in the percentage of macrophages between the acute and recovery stages (P > 0.05). The RMPP group had a significantly higher MP load in BALF in both the acute and recovery stages than the control group (P < 0.01), and the MP load in the acute stage was significantly higher than in the recovery stage (P < 0.01). In the children with RMPP, galectin-3 level in BALF in the acute stage was positively correlated with MP load and the percentage of neutrophils (r_s=0.789 and 0.726 respectively; P < 0.01). Conclusions Galectin-3 is involved in the process of airway inflammation in children with RMPP, and the level of galectin-3 in BALF is positively correlated with MP load. RMPP is a cellular immune inflammatory lesion with the increase of neutrophils and the reduction in macrophages. Galectin-3 is closely associated with neutrophil chemotaxis and luminal infiltration in children with RMPP. MP load gradually decreases with the recovery from RMPP, but it is not completely eliminated by the immune system in the recovery stage. MP infection can increase the consumption of macrophages in children with RMPP.

Objective To study the association of cytoplasmic phospholipase A2 (PLA2G4) rs932476 polymorphism with the development of bronchial asthma and the response to montelukast, a leukotriene receptor antagonist, in children. Methods A total of 128 children with bronchial asthma were enrolled as case group, and 100 healthy children were enrolled as control group. The genotype and allele frequencies of PLA2G4 rs932476 were compared between the two groups. The children in the case group were administered with montelukast except routine treatment for 2 months, and the changes in serum levels of leukotriene B4 (LTB4), interleukin-4 (IL-4), immunoglobulin E (IgE), and interferon gamma (IFN-γ), pulmonary function and fractional exhaled nitric oxide (FeNO) after treatment were observed. Results There were no significant differences in the genotype and allele frequencies of PLA2G4 rs932476 between the case and control groups, as well as between the groups with different severities of asthma (P > 0.05). After treatment, the children with AA genotype had a significantly higher overall response rate than those with GG genotype. After treatment, the case group had significant reductions in the serum levels of IgE and IL-4 and a significant increase in the level of IFN-γ (P < 0.05). After treatment, the children with GG genotype had a higher serum level of IL-4 and a lower level of IFN-γ than those with AA genotype. After treatment, the case group had significant increases in pulmonary function parameters, and the children with AA genotype had significantly higher parameters than those with GG genotype. The case group had a significant reduction in the level of FeNO, and the children with AA genotype had a significantly lower level than those with GG genotype after treatment. The case group had a significantly higher serum level of LTB4 than the control group before treatment (P < 0.05). After treatment the case group had a significant reduction in the serum level of LTB4 (P < 0.05). The children with GG genotype had a significantly higher level of LTB4 than those with AA genotype after treatment (P < 0.05). Conclusions PLA2G4 rs932476 polymorphism is not associated with the susceptibility and severity of bronchial asthma in children, but it may has certain influence on children's response to the leukotriene receptor antagonist montelukast, possibly by affecting the level of LTB4.

Objective To study the expression of the Fra-1 gene in the peripheral blood of children with Wilms tumor and its clinical significance. Methods Fifty children pathologically diagnosed with Wilms tumor between December 2012 and January 2018 were enrolled as the case group, and 40 healthy children for physical examination were selected as the control group. Among the 45 children with Wilms tumor who were followed up, the children with continuous remission were included in the ideal efficacy group (n=33), and those with recurrence, metastasis or death were included in the poor efficacy group (n=12). Peripheral blood samples were collected from all subjects. Quantitative real-time PCR was used to measure the mRNA expression of Fra-1. Results The case group had significantly higher mRNA expression of Fra-1 in peripheral blood than the control group (P < 0.05). In the case group, Fra-1 mRNA expression was significantly different between the individuals with and without distant metastasis and those with different TNM stages (P < 0.05), but was not significantly different between the individuals with different sexes, ages, tumor diabetes, tumor locations and alpha-fetoprotein levels (P > 0.05). The mRNA expression of Fra-1 was significantly lower in the ideal efficacy group than in the poor efficacy group (P < 0.05). Conclusions Fra-1 may be involved in the development of Wilms tumor and plays a certain role in its development, invasion and metastasis, but the mechanism remains to be further studied.

Objective To study the clinical features of nephrotic syndrome (NS) accompanied by eosinophilia in children. Methods A retrospective analysis was performed for the clinical manifestations, laboratory findings and treatment outcomes of 18 cases of eosinophilia (15 children, 3 of whom also had eosinophilia at the second recurrence) in children with NS. Results Of the 18 cases, 16 (89%) had mild eosinophilia, 1 (6%) had moderate eosinophilia, and 1 (6%) had severe eosinophilia. Twelve cases (67%) developed eosinophilia in winter and spring. Nine cases (50%) had infectious diseases:pneumonia (including 2 cases of Mycoplasma pneumonia) in 4 cases, EB virus infection in 3 cases, suspected pinworm infection in 1 case, and Streptococcal infection in 1 case. Five cases (28%) had allergic diseases:urticaria in 2 cases, allergic rhinitis in 2 cases and eczema in 1 case. There was no significant correlation between eosinophil count and the levels of urinary protein, serum albumin and cholesterol (P > 0.05). In 8 cases of newly diagnosed NS, urinary protein turned negative within 4 weeks after glucocorticoid treatment. In 10 cases of recurrent NS, urinary protein turned negative in 9 cases after the adjustment of glucocorticoid treatment. In 1 case of recurrent NS (moderate eosinophilia with allergic rhinitis), symptomatic relief and negative urinary protein were achieved after anti-allergic treatment. Glucocorticoid therapy was not administered again in the patient, and the eosinophil count was reduced to a slight increase. The eosinophil counts of the other 17 cases returned to normal. Conclusions NS with eosinophilia in children occurs mostly in winter and spring. This disorder is associated with infection or allergic diseases. There was no significant correlation between eosinophil count and the levels of urinary protein, serum albumin and cholesterol.

Objective To study the clinical effect of alanyl-glutamine-enriched nutritional support in the treatment of children with abdominal Henoch-Schönlein purpura. Methods Children with abdominal Henoch-Schönlein purpura who needed nutritional support were enrolled and stratified according to age, sex and the severity of disease, and were randomly divided into a control group (n=118) and an enriched nutritional support group (n=107). The control group was given nutritional support without using alanyl-glutamine, while the enriched nutritional support group was given alanyl-glutamine-enriched nutritional support. Intravenous steroids were used according to the severity of disease in both groups. Other therapies were the same in the two groups. The two groups were compared in terms of the length of hospital stay, the rate and duration of use of intravenous steroids, the recurrence rate of symptoms during hospitalization, the rate of total parenteral nutrition (TPN), the rate of weight loss and the rate of fasting for more than 5 days. All patients were followed up for 3 months after discharge to monitor the recurrence of symptoms. Results There were no significant differences in the length of hospital stay, the rate of TPN and the rate of fasting for more than 5 days between the two groups (P > 0.05). Compared with the enriched nutritional support group, the control group showed significant increases in the rate and duration of use of intravenous steroids, the recurrence rate of symptoms and the rate of weight loss (P < 0.05). After the 3-month follow-up, all the children resumed normal diet, and the recurrence rate of digestive symptoms was less than 20% in each group. Abdominal pain was the most common symptom (83.33%, 30/36), followed by vomiting and abdominal distention. No digestive hemorrhage was observed. All the symptoms were relieved after symptomatic treatment. No significant difference was found between the two groups in the recurrence rate of digestive symptoms (P=0.693). Conclusions Alanyl-glutamine-enriched nutritional support in the treatment of children with abdominal Henoch-Schönlein purpura can reduce the use of intravenous steroids and weight loss, but without impact on the length of hospital stay and post-discharge recurrence.

Objective To explore the value of galactose-deficient IgA1 (Gd-IgA1) in the early diagnosis of Henoch-Schönlein purpura nephritis (HSPN) in children. Methods A total of 67 hospitalized children who were definitely diagnosed with HSPN between January and April 2018 and 58 hospitalized children with Henoch-Schönlein purpura (HSP) were enrolled in the study. Twenty children undergoing routine physical examinations served as controls. The levels of serum and urine Gd-IgA1 were determined using ELISA. The receiver operating characteristic curve was used to analyze the value of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in the diagnosis of HSPN. Results The level of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in children with HSP or HSPN were significantly higher than those in healthy control group (P < 0.01), with a significantly greater increase observed in children with HSPN (P < 0.01). Serum Gd-IgA1 ≥ 1485.57 U/mL and/or urine Gd-IgA1/urine creatinine ratio ≥ 105.74 were of favorable value in the diagnosis of HSPN. During the six-month follow-up of the 49 children with HSP, the incidence of HSPN was 47% (23/49), which included a 100% incidence in children with serum Gd-IgA1 ≥ 1485.57 U/mL and a 73% incidence in children with urine Gd-IgA1/urine creatinine ratio ≥ 105.74. Conclusions Serum and urine Gd-IgA1 is of favorable clinical value in the early diagnosis of HSPN.

The patient was a female infant aged 1 month and 29 days. She was admitted to the hospital due to convulsions for 6 days and increased blood glucose level for 5 days. She had unstable blood glucose levels. The level of glycosylated hemoglobin was too high to measure. Urine glucose was positive (+-++++). The levels of fasting C-peptide and insulin were 0.19 ng/mL and 11.68 μIU/mL respectively. High-throughput sequencing of the genetic endocrine disease gene Panel (412 detected genes, including 49 known diabetes-related genes) showed that the EIF2AK3 gene in the infant had two novel compound heterozygous mutations, c.2731_2732delAG and c.2980G > A, both of which were located in the kinase domain. The infant was diagnosed with Wolcott-Rallison syndrome (WRS). As a rare autosomal recessive disease, WRS is characterized by neonatal diabetes, multiple epiphyseal dysphasia and liver disease. Neonatal diabetes is a prerequisite for the diagnosis of WRS. The EIF2AK3 gene is the pathogenic gene of WRS.

Objective To study the distribution of peripheral blood lymphocyte subsets in healthy children aged 0-6 years. Methods A total of 826 healthy Han children aged 0-6 years were recruited. According to their age, the children were divided into four groups:newborn, infant, toddler and preschool. Their peripheral blood samples were collected to measure the percentages of lymphocyte subsets by flow cytometry. Results There were significant differences in the percentages of CD3⁺ T cells, CD3⁺CD4⁺ T cells and CD3^-CD19⁺ B cells and the CD4⁺/CD8⁺ ratio between boys and girls (P < 0.05). The girls had a lower percentage of CD3^-CD19⁺ B cells, higher percentages of CD3⁺ T cells and CD3⁺CD4⁺ T cells and a higher CD4⁺/CD8⁺ ratio than the boys. The newborn group had the highest percentages of CD3⁺ T cells and CD3⁺CD4⁺ T cells and the highest CD4⁺/CD8⁺ ratio (P < 0.05). The percentage of CD3⁺CD4⁺ T cells and the CD4⁺/CD8⁺ ratio gradually decreased with age and the preschool group had the lowest values (P < 0.05). The newborn group had the lowest percentages of CD3^-CD19⁺ B cells and CD3^-CD16⁺CD56⁺ NK cells (P < 0.05). The percentage of CD3^-CD16⁺CD56⁺ NK cells gradually increased with age and the preschool group had the highest percentage (P < 0.05). The percentage of CD3^-CD19⁺ B cells reached the peak in the toddler period and then decreased with age (P < 0.05). The preschool group had the highest percentage of CD3⁺CD8⁺ T cells (P < 0.05). The variation trend of distribution of lymphocyte subsets in boys from different age groups was consistent with that in children from different age groups. For girls, the newborn group had the highest percentage of CD3⁺CD4⁺ T cells and CD4⁺/CD8⁺ ratio (P < 0.05). Conclusions The distribution of peripheral blood lymphocyte subsets in healthy children is significantly different across ages and sexes. Therefore, the reference values should be established according to age and sex.

Objective To investigate the prevalence of social anxiety among the fourth-, fifth-and sixth-grade primary school students with myopia in Urumqi, China and the risk factors for social anxiety. Methods Stratified cluster random sampling was used to select 552 fourth-, fifth-and sixth-grade primary school students with myopia from four primary schools in Urumqi. A self-designed questionnaire, a social anxiety scale for children and a self-esteem scale were used to investigate the general demographic data and the current status of social anxiety and self-esteem. A multivariate logistic regression analysis was used to investigate the risk factors for social anxiety in primary school students with myopia. Results Of the 552 children, 173 (31.3%) were found to have social anxiety. The multivariate logistic regression analysis showed that a higher grade, female sex, autocratic family, high myopia, low self-esteem and wearing glasses for more than 2 years were risk factors for social anxiety (P < 0.05). Conclusions There is a serious problem of social anxiety among the fourth-, fifth-and sixth-grade primary school students with myopia in Urumqi. The development of social anxiety is associated with age, sex, degree of myopia, time of wearing glasses, parental education style and self-esteem level.

No abstract available

Objective To study the effect of calcium-sensitive receptors (CaSR) on the expression of endothelial nitric oxide synthase (eNOS) and the concentration of nitric oxide (NO) in a neonatal mouse model of persistent pulmonary hypertension (PPH). Methods Eighty neonatal C57BL/6 mice were randomly divided into control, PPH, agonist and antagonist groups. The control group was exposed to air, and the other three groups were exposed to 12% oxygen. The agonist and antagonist groups were intraperitoneally injected with a CaSR agonist (GdCl₃ 16 mg/kg) and a CaSR antagonist (NPS2390, 1 mg/kg), respectively, while the PPH and control groups were intraperitoneally injected with normal saline instead. All mice were treated for 14 days. Alveolar development and pulmonary vessels were assessed by hematoxylin-eosin staining. The protein and mRNA expression of eNOS and its localization in lung tissues were determined by Western blot, qRT-PCR and immunohistochemistry. The levels of brain natriuretic peptide (BNP) and NO in lung homogenate were determined using ELISA. Results Compared with the control group, the PPH and agonist groups showed significant increases in alveolar mean linear intercept, the percent wall thickness of pulmonary arterioles, right to left ventricular wall thickness ratio (RV/LV) and BNP concentration, but a significant reduction in radial alveolar count (P < 0.05). The antagonist group had significant improvements in all the above indices except RV/LV compared with the PPH and agonist groups (P < 0.05). Compared with those in the control group, the protein and mRNA expression of eNOS and NO concentration were significantly increased in the PPH group and increased more significantly in the agonist group, but were significantly reduced in the antagonist group (P < 0.05). Conclusions CaSR plays an important role in the development of PPH in neonatal mice, possibly by increasing eNOS expression and NO concentration.