Characteristics of home oxygen therapy for preterm infants with bronchopulmonary dysplasia in China: results of a multicenter cohort study.

BACKGROUND: Home oxygen therapy (HOT) is indicated upon discharge in some preterm infants with severe bronchopulmonary dysplasia (BPD). There is a lack of evidence-based consensus on the indication for HOT among these infants. Because wide variation in the institutional use of HOT exists, little is known about the role of regional social-economic level in the wide variation of HOT. METHODS: This was a secondary analysis of Chinese Neonatal Network (CHNN) data from January 1, 2019 to December 31, 2019. Infants at gestational ages < 32 weeks, with a birth weight < 1500 g, and with moderate or severe BPD who survived to discharge from tertiary hospitals located in 25 provinces were included in this study. Infants with major congenital anomalies and those who were discharged against medical advice were excluded. RESULTS: Of 1768 preterm infants with BPD, 474 infants (26.8%) were discharged to home with oxygen. The proportion of HOT use in participating member hospitals varied from 0 to 89%, with five of 52 hospitals' observing proportions of HOT use that were significantly greater than expected, with 14 hospitals with observing proportions significantly less than expected, and with 33 hospitals with appropriate proportions. We noted a negative correlation between different performance groups of HOT and median GDP per capita (P = 0.04). CONCLUSIONS: The use of HOT varied across China and was negatively correlated with the levels of provincial economic levels. A local HOT guideline is needed to address the wide variation in HOT use with respect to different regional economic levels in countries like China.

Primary repair of esophageal atresia gross type C via thoracoscopic magnetic compression anastomosis: A case report.

BACKGROUND: Esophageal atresia (EA) is a life-threatening congenital malformation in newborns, and the traditional repair approaches pose technical challenges and are extremely invasive. Therefore, surgeons have been actively investigating new minimally invasive techniques to address this issue. Magnetic compression anastomosis has been reported in several studies for its potential in repairing EA. In this paper, the primary repair of EA with magnetic compression anastomosis under thoracoscopy was reported. CASE SUMMARY: A full-term male weighing 3500 g was diagnosed with EA gross type C. The magnetic devices used in this procedure consisted of two magnetic rings and several catheters. Tracheoesophageal fistula ligation and two purse strings were performed. The magnetic compression anastomosis was then completed thoracoscopically. After the primary repair, no additional operation was conducted. A patent anastomosis was observed on the 15th day postoperatively, and the magnets were removed on the 23rd day. No leakage existed when the transoral feeding started. CONCLUSION: Thoracoscopic magnetic compression anastomosis may be a promising minimally invasive approach for repairing EA.

[Combined immunoprophylaxis induces changes in anti-hepatitis B surface protein titer in infants born to mothers with positivity for hepatitis B surface antigen].

OBJECTIVE: To conduct a prospective randomized controlled trial of infants born to hepatitis B virus (HBV) surface antigen (HBsAg)-positive mothers in order to investigate the dynamic changes in the titer of anti-HBV surface protein (HBS) induced by treatment with combined immunoprophylaxis (200 IU hepatitis B immunoglobulin (HBIG) and 5 or 10 mug yeast recombinant hepatitis B vaccine), to compare the protective effect of 5 and 10 mug hepatitis B vaccine, and to provide an immunization strategy, monitoring mode and booster immunization schedule for the high-risk group. METHODS: Two-hundred-and-sixty-nine infants born to HBsAg positive mothers were given combined immunoprophylaxis at birth, and the venous blood samples (at birth, and 1, 7 and 12 months) were tested for HBV DNA load, and HBsAg and anti-HBS titers. RESULTS: The overall 1-year protective rate of combined immunoprophylaxis was 95.9%. There was no significant difference between the infectious rates of infants given the 5 mug or the 10 mug hepatitis B vaccine (x2 = 0.876, P = 0.377). The geometric mean titers (GMTs) of anti-HBS were 144.1 mIU/ml at 1-month old and 564.9 mIU/ml at the age of 7 months old (the highest point), but declined to 397.6 mIU/ml at the age of 12 months old. The rate of infants with anti-HBS titer less than 100 mIU/ml was 20.9%, and that of less than 10 mIU/ml was 7.4% at 7-month-old; the rate of infants with anti-HBS titer less than 100 mIU/ml increased to 30.2% and that of less than 10 mIU/ml increased to 15.9% at 12-month-old. At 7-month-old, the GMT of the 10 mug vaccine group was higher than that of the 5 mug vaccine group (675.3 mIU/ml vs. 25.0 mIU/ml, P = 0.001) and the rate of infants with anti-HBS titer less than 10 mIU/ml was significantly lower in the 10 mug vaccine group (2.3% vs. 12.6%, P = 0.002); at 12-month-old, the rate of infants with anti-HBS titer less than 100 mIU/ml was also significantly lower in the 10 mug group (20.6% vs. 40.2%, P = 0.001). CONCLUSION: Combined immunoprophylaxis is therapeutically efficacious for treating infants born to HBsAg positive mothers. Monitoring these infants' anti-HBs titer will help to identify non- or low-responders in a timely manner. The high-dose hepatitis B vaccine is preferable to the low-dose, and should be considered for use in immunization strategies for these infants.

[Detection of genetic defect within ABCA3 from newborns with respiratory distress syndrome].

OBJECTIVE: To detect possible relationship between genetic defect within the gene encoding member A3 of the ATP Binding Cassette family (ABCA3) and neonatal respiratory distress syndrome (NRDS), thus to understand the genetic mechanisms of NRDS in Han ethnic group. METHOD: The clinical data of 11 cases with NRDS hospitalized in neonatal intensive care unit was investigated. Blood samples were collected from 11 cases with NRDS and 97 unassociated normal individuals. Polymerase chain reaction (PCR) and DNA direct sequencing were performed to screen all exons and their flanking introns of ABCA3 gene for mutation analysis in 11 cases with NRDS. If a new missense variation was identified, single strand conformation polymorphism analysis was performed in 97 healthy controls. Lung tissue sample from a case who died 12 hours after birth was examined with light microscopy and electron microscopy. RESULT: Three missense genetic variants in exons, which include c. 2169 G > A (p.M723I), c. 1010 T > G (p.V337G), c. 4972 A > G (p.S1658G), one splice junction site variation (Exon 30 + 2 T/G), several unreported polymorphism sites [213 C > T(p.F71F), exon 21 + 34C/T] and reported polymorphism site (p.F353F) were identified on ABCA3 gene coding region in 11 case. The homozygous variation (c.2169G > A), which was in exon 17 and causes an M723I amino acid change, was found in the case who died 13 hours after birth, but not detected in 97 controls, indicating that this variation is indeed a mutation and not a polymorphism. In the case carrying c.2169G > A, ultrastructural examination of the alveolar type II cells with electron microscopy demonstrated abnormally small and dense lamellar body with eccentrically distributed electron dense substance. CONCLUSION: Genetic variants within ABCA3 may be the genetic cause of or a contributor to some unexplained refractory NRDS. Identification of ABCA3 genetic variant in NRDS infants is important to establish appropriate management and evaluation of treatment options, as well as to offer genetic counseling and prenatal diagnosis.

Site-directed mutagenesis of neonatal convulsions associated KCNQ2 gene and its protein expression.

OBJECTIVE: To study the protocol of construction of a KCNQ2-c.812G>T mutant and its eukaryotic expression vector, the c.812G>T (p.G271V) mutation, which was detected in a Chinese pedigree of benign familial infantile convulsions (BFIC), and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells. METHODS: A KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules. RESULTS: Direct sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells. CONCLUSIONS: Successful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.

[Site-directed mutagenesis and protein expression of KCNQ2 gene associated with neonatal convulsions].

OBJECTIVE: To study the protocol of construction of a KCNQ2-c.812G>T mutant and it's eukaryotic expression vector, the c.812G>T (p.G271V) mutation which was detected in a Chinese pedigree of benign familial infantile convulsions, and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells. METHODS: A KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules. RESULTS: Direct sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells. CONCLUSIONS: Successful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.

[Polyclonal antibody preparation and characterization of mouse Rnf141].

OBJECTIVE: To obtain the Rnf141 polyclonal antibody and to study its function. METHODS: Rnf141 cDNA was obtained by PCR amplification and inserted into the expression vector pGEX-5X-3, which encoding the GST protein to generate a recombinant plasmid. The recombinant was transformed into E. coli BL21 (DE3). After inducing with 1 mmol/L IPTG at 25 degrees C, the GST-Rnf141 fusion protein was expressed at a high level as a soluble form. Purified fusion protein with Glutathione Sephorase 4B chromatography was applied to immune rabbits to prepare the polyclonal antibody. Western blot and immunohistochemistry were applied to confirm the specificity of the resulting antibody. RESULTS: pGEX-Rnf141 recombinant plasmid was constructed successfully and the resulting. GST-Rnf141 fusion protein could be expressed in E. coli BL21(DE3) at a relatively high level, standing for 46% of total bacteria protein. The titer of the antiserum was 1:128000 and the polyclonal antibody could recognize GST-Rnf141 fusion protein and Rnf141 protein in different tissues of mouse. The high expression of Rnf141 protein was observed in spleen and brain of mouse. CONCLUSION: Rnf141 polyclonal antibody was prepared successfully and this will provide material for further studies of Rnf141 expression and function.