TGF-α/EGFR signaling promotes lipopolysaccharide-induced abnormal elastin deposition and alveolar simplification.

Bronchopulmonary dysplasia (BPD) is characterized by shortened secondary septa and fewer, larger alveoli. Elastin deposition to the distal tips of the secondary septa is critical for elongation of the secondary septa. Alveolar myofibroblasts, which are thought to migrate to the septal tips during alveolarization, are mainly responsible for elastin production and deposition. Antenatal exposure to inflammation induces abnormal elastin deposition, thereby increasing the risk of developing BPD. Here, we found that lipopolysaccharide (LPS) significantly increased the expression of transforming growth factor-α (TGF-α) in an LPS-induced rat model of BPD and in LPS-treated human pulmonary epithelial cells (BEAS-2B). In addition, in vitro experiments suggested that LPS upregulated TGF-α expression via toll-like receptor 4 (TLR4)/tumor necrosis factor α-converting enzyme (TACE) signaling. Increased TGF-α levels via its receptor epidermal growth factor receptor (EGFR)-induced lysyl oxidase (LOX) overactivation and cell division cycle 42 (Cdc42) activity inhibition of myofibroblasts. Similarly, in vivo LOX overactivation and inhibition of Cdc42 activity were observed in the lungs of LPS-exposed pups. LOX overactivation led to abnormal elastin deposition, and inhibition of Cdc42 activity disturbed the directional migration of myofibroblasts and disrupted elastin localization. Most importantly, the EGFR inhibitor erlotinib partially rescued LOX overactivation and Cdc42 activity inhibition, and improved elastin deposition and alveolar development in antenatal LPS-treated rats. Taken together, our data suggest that TGF-α/EGFR signaling is critically involved in the regulation of elastin deposition and represents a novel therapeutic target.

Association between Neonatal Outcomes and Admission Hypothermia among Very Preterm Infants in Chinese Neonatal Intensive Care Units: A Multicenter Cohort Study.

OBJECTIVE: We aimed to investigate the relationship between admission hypothermia and outcomes among very preterm infants (VPIs) in neonatal intensive care units (NICUs) in China. We also investigated the frequency of hypothermia in VPIs in China and the variation in hypothermia across Chinese Neonatal Network (CHNN) sites. STUDY DESIGN: This retrospective cohort study enrolled infants with 240/7 to 316/7 weeks of gestation with an admission body temperature ≤37.5 °C who were admitted to CHNN-participating NICUs between January 1 and December 31, 2019. RESULTS: A total of 5,913 VPIs were included in this study, of which 4,075 (68.9%) had hypothermia (<36.5 °C) at admission. The incidence of admission hypothermia varied widely across CHNN sites (9-100%). Lower gestational age (GA), lower birth weight, antenatal steroid administration, multiple births, small for GA, Apgar scores <7 at the 5th minute, and intensive resuscitation were significantly associated with admission hypothermia. Compared with infants with normothermia (36.5-37.5 °C), the adjusted odds ratios (ORs) for composite outcome among infants with admission hypothermia <35.5 °C increased to 1.47 (95% confidence interval [CI], 1.15-1.88). The adjusted ORs for mortality among infants with admission hypothermia (36.0-36.4 and <35.5 °C) increased to 1.41 (95% CI, 1.09-1.83) and 1.93 (95% CI, 1.31-2.85), respectively. Admission hypothermia was associated with a higher likelihood of bronchopulmonary dysplasia, but was not associated with necrotizing enterocolitis ≥stage II, severe intraventricular hemorrhage, cystic periventricular leukomalacia, severe retinopathy of prematurity, or sepsis. CONCLUSION: Admission hypothermia remains a common problem for VPIs in a large cohort in China and is associated with adverse outcomes. Continuous quality improvement of admission hypothermia in the future may result in a substantial improvement in the outcomes of VPIs in China. KEY POINTS: · Admission hypothermia is common in VPIs.. · The incidence of admission hypothermia in VPIs remains high in China.. · Admission hypothermia is associated with adverse outcomes in VPIs..

The molecular basis of brain injury in preterm infants with sepsis - associated encephalopathy.

Sepsis-associated encephalopathy (SAE) is characterized by brain dysfunction during sepsis, without central nervous system infection. Here, we explored the molecular basis of brain injury in preterm infants with SAE. From Jan 2016 to Dec 2019, a total of 20 preterm infants were hospitalized in the neonatal intensive care unit (NICU) of our hospital, including 10 preterm infants with SAE (SAE group) and 10 preterm infants without encephalopathy after sepsis (no SAE group). Among the 20 premature infants, there were 12 males and 8 females, with mean gestational age 31.0 ± 2.46 weeks, 7 cases with birth weight ≤ 1500 g and 13 cases with birth weight 1500-2500 g. Blood cultures were negative in 6 cases and positive in 14 cases, including 10 cases of Gram-negative and 4 cases of Gram-positive bacteria, respectively. Expression levels of messenger RNA (mRNA) and MicroRNA (miRNA) were analyzed in peripheral blood samples from both groups during sepsis. There were 1858 upregulated and 2226 downregulated mRNAs [fold-change (FC) > |2|, p < 0.05], and 322 upregulated and 160 downregulated miRNAs (FC > |2|, p < 0.05), respectively, in the SAE group compared with the no SAE group. Expression levels of miRNA-1197 [95% confidence intervals (CI), 0.042 to 0.166] were 6.03-fold higher in the SAE group than the no SAE group, while those of miRNA-485-5p (95% CI, 0.064 to 0.024) were lower (0.31-fold). Both high expression of miRNA-1197 and low expression of miRNA-485-5p may be associated with pathogenic alteration of the oxidative respiratory chain and energy metabolism in preterm infants with SAE.

[Identification of a homozygous ASS1 mutation in a child with citrullinemia type â with high-melting curve method].

OBJECTIVE: To carry out rapid genetic diagnosis for a child affected with citrullinemia type Ⅰ. METHODS: Peripheral venous blood samples were obtained from the two-day-old child and his parents as well as 100 healthy controls. Serum ammonia and citrulline was determined by biochemical test and tandem mass spectrometry. Sixteen pairs of primers were designed for high-resolution melting (HRM) analysis of all exons and adjacent intronic sequences of the ASS1 gene in the proband, parents and healthy controls. Suspected mutations were confirmed by DNA sequencing, while the mRNA transcripts of the ASS1 gene were determined by reverse transcription (RT)-PCR. Functional impact of the mutation sites was predicted with PolyPhen-2 and SIFT Blink software. RESULTS: Blood ammonia and citrulline of the proband have respectively reached 286 µmol/L and 487.69 µmol/L, which far superseded the normal values. HRM analysis and DNA sequencing have identified in the child a homozygous c.380G>A (p.R127Q) mutation in exon 6 of the ASS1 gene, in addition with a homozygous IVS8+60G>A substitution in intron 8, while his parents were heterozygous carriers for both mutations. RT-PCR assay indicated that the IVS8+60G>A mutation did not result in abnormal splicing of the ASS1 gene transcripts. Bioinformatic analysis suggested that the site for p.R127Q was conserved among 45 species of vertebrates and may play a crucial role in citrulline metabolism. CONCLUSION: The severe urea cycle disorder in the proband was probably due to the compound homozygous R127Q and IVS8+60G>A mutations of the ASS1 gene.

[Rapid screening for MTHFR gene 677C>T polymorphism in Down syndrome using high resolution melting curve and pyrosequencing].

OBJECTIVE: To establish a rapid method for detecting MTHFR gene 677C>T polymorphisms with high-resolution melting curve method (HRM) and pyrosequencing. METHODS: Peripheral blood samples were collected from 155 Down syndrome patients and 182 normal controls from Children's Hospital of Shanghai. The accuracy of three methods including regular HRM, internal control HRM and artificial heterozygosity HRM was compared. Meanwhile, allele frequencies in 10, 30 and 50 mixed samples were measured with pyrosequencing, and the results were compared with that of HRM. RESULTS: Heterozygosity of 677C>T polymorphism could be distinguished by various HRM methods. However, homozygotes CC and TT were only identifiable by internal control HRM and artificial heterozygosity HRM. The accuracy of pyrosequencing for allele frequency has improved with increased sample number. When the number of mixed samples has exceeded 30, the difference between pyrosequencing results and actual values became less than 4%. TT genotype was more frequent in Down syndrome patients than controls (25.2% vs. 14.3%). No significant difference was found in T allele frequency between the two groups (44.9% vs. 40.1%). CONCLUSION: Respectively, internal control HRM and pyrosequencing may be ideal methods for determination of genotypic and allelic frequencies.

Streptococcus gallolyticus Subspecies pasteurianus Meningitis in an Infant with Hypothyroidism and Diarrhea.

Streptococcus gallolyticus subspecies pasteurianus, formerly classified as S. bovis biotype II/2 until 2003, is a rare cause of infant meningitis. Over the past 2 decades, only a few individual case reports and limited case series exist in the English-language literature. Moreover, the pathogenesis of S. gallolyticus subsp. pasteurianus meningitis in infants is unclear. Here we report a case of meningitis in a 6-week-old infant with hypothyroidism and preceding diarrhea. In this case, S. gallolyticus was cultured from cerebrospinal fluid, and then S. gallolyticus subspecies pasteurianus was identified by metagenomic next-generation Sequencing. The infant recovered uneventfully after a 4-week antibiotic course with ceftriaxone and vancomycin. Then combined with the literature of S. gallolyticus subsp. pasteurianus meningitis in infants, we discuss the possible etiology.

Severe Intravascular Hemolysis from Clostridium perfringens Septicemia in a Neonate with Necrotizing Enterocolitis in China: A Case Report.

Clostridium perfringens (C. perfringens) is a gram-positive anaerobic bacillus. As an opportunistic pathogen, C. perfringens can colonize the intestine of infants, but highly pathogenic forms are uncommon in newborns. Sporadic cases of neonatal infection have been reported worldwide, but no case has yet been reported in Chinese neonates. We herein report the first Chinese neonate who developed severe intravascular hemolysis and necrotizing enterocolitis following C. perfringens septicemia. A 7-day-old full-term female newborn was admitted to our hospital with necrotizing enterocolitis. The patient developed severe intravascular hemolysis on the day of admission and underwent continuous renal replacement therapy for hyperkalemia and severe acute kidney injury. Despite optimal treatment, this baby died at 20 hours after admission. Clinical metagenomic next-generation sequencing for pathogen detection showed a positive result for C. perfringens. Literature on C. perfringens-associated sepsis in neonates was reviewed to offer a reference for clinical practice. Our case demonstrates that neonatologists should consider a diagnosis of C. perfringens infection in a newborn when symptoms of severe intestinal infection and intravascular hemolysis are present, so that early treatment can be initiated.

Efficiency Evaluation of Neuroprotection for Therapeutic Hypothermia to Neonatal Hypoxic-Ischemic Encephalopathy.

Background: To evaluate the safety and neurological outcomes of therapeutic hypothermia to neonatal hypoxic-ischemic encephalopathy (HIE). Materials and Methods: Medical records of 61 neonates with moderate to severe HIE were retrospectively enrolled and divided into a therapeutic hypothermia group (n = 36) and conventional therapy group (n = 25). Results: No significant difference in the incidence of severe adverse events was found between the two groups. Minimum and maximum voltages of amplitude-integrated electroencephalography (aEEG) recording results showed statistically significant differences in therapeutic hypothermia group after 72 h. The neonatal behavioral neurological assessment (NBNA) on the 28th day after birth and Bayley Scales of Infant Development, second edition (BSID II) scores at 18 months old were significant higher in the therapeutic hypothermia group than the conventional therapy group. Conclusion: Therapeutic hypothermia for neonates with moderate to severe HIE improved the development of the nervous system in 0-18-month-old infants and showed a predominant role in reducing death and major neuron development-associated disabilities.

Clinical Analysis of Intravenous and Oral Sequential Treatment With Voriconazole for Candida Central Nervous System Infection in Six Premature Infants.

Objective: The aim of the study was to observe the clinical efficacy and safety of intravenous and oral sequential treatment with voriconazole for Candida central nervous system (CNS) infection in premature infants. Methods: The study included retrospective analysis of the clinical data of six premature infants with Candida CNS infection admitted to the neonatology department in Shanghai Children's Hospital between November 2016 and November 2019. By reviewing the characteristics of voriconazole based on the literature, it showed that infants without gastrointestinal dysfunction could be effectively treated by intravenous and oral sequential therapy with voriconazole (both 7 mg/kg/dose, every 12 h). Clinical manifestations, the time required for the cerebrospinal fluid (CSF), blood culture, nonspecific infection markers such as platelets and C-reactive protein (CRP) to turn normal, and drug-related side effects were observed and recorded in the process of treatment. All data were statistically analyzed by T test and Mann-Whitney U test. Results: A total of six premature infants were diagnosed with Candida CNS infection, two cases were diagnosed by a positive CSF culture and four cases were clinically diagnosed. Blood culture was positive for Candida in five cases. Among the 6 patients, 4 cases were Candida albicans and 2 cases were Candida parapsilosis. All the six cases were cured. After 3-5 days of treatment, symptoms such as lethargy, apnea, and feeding intolerance were improved and disappeared; a repeated blood culture turned negative in 3-7 days; CSF returned to normal in 15 ± 9 days on an average. Brain abscess, meningeal inflammation, and other infectious lesions were cleared on cranial magnetic resonance imaging (MRI) after treatment. The average total course of voriconazole was 61 ± 29 days, and the average oral treatment was 28 ± 15 days. No Candida recurrence was found during the treatment, and no drug-related side effects such as skin rash, liver and kidney function impairment, or visual abnormalities were found. The white blood cells, CSF glucose/plasma glucose ratio, and protein in CSF were significantly improved after the treatment (p < 0.05). No statistically significant difference was identified in the liver and kidney function indexes (p > 0.05). Conclusion: Voriconazole is a relatively safe and effective alternative treatment for Candida CNS infection in preterm infants. No severe drug-related side effects were detected.

A Case of Sepsis Due to Carbapenem-Resistant Klebsiella pneumoniae in an Extremely Low-Birth Weight Infant Treated with Trimethoprim-Sulfamethoxazole.

In recent years, there have been an increasing number of infections due to multidrug-resistant organisms in the neonatal intensive care unit. Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a challenge in clinical anti-infection treatment. Herein, we report the case of CRKP sepsis in an extremely low-birth weight infant (ELBWI) who did not respond to meropenem and vancomycin, but was treated successfully after a 10-day antibiotic course with trimethoprim-sulfamethoxazole (TMP-SMZ). Recent research on CRKP-associated sepsis and the application of TMP-SMZ therapy in children and neonates were reviewed to offer a reference for clinical practice.

The clinical safety and efficacy of flexible bronchoscopy in a neonatal intensive care unit.

Flexible bronchoscopy (FB), developed in the 1960s, is widely used in the clinical practice of pediatrics and has demonstrated fundamental value in clinical diagnoses and treatment. However, as an invasive procedure, the use of FB is limited due to concerns regarding the tolerance of the procedure and the possible complications in neonatal units. Thus, the present study aimed to investigate the clinical safety and efficacy of flexible bronchoscopy (FB) in a neonatal intensive care unit (NICU). Neonates (n=54) who received FB in the NICU of Shanghai Children's Hospital between January 2012 and December 2016 were enrolled as the experimental group and another 54 neonates who required nebulization and tracheal secretion suction treatments were the control group. Indicators including blood gas, complete blood count, C-reactive protein (CRP), X-ray, patient breathing rate, temperature and blood pressure were monitored prior to and following the procedure. No significant differences in sex, gestational age, birth weight or postnatal age were observed between the experimental group and the control group (P>0.05). Among the 54 FB patients, several cases with side effect were identified, including 18 (33.3%) with respiratory tract stenosis, nine (16.7%) with malacia and stenosis and six (11.1%) with esophagotracheal fistula. Among the 54 members of the control group, 44 neonates (81.4%) were discharged with improved condition, five (9.3%) succumbed and five patients (9.3%) abandoned the treatment and left the hospital. Bronchoalveolar lavage demonstrated consistent results with respiratory secretion culture or tracheal tube culture. In comparison between the experimental and the control groups, no significant difference in pH, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2) and HCO3 - was observed, while there were no statistical differences in the values of pH, PCO2 and HCO3 - (P>0.05). However, PO2 was significantly increased, and CRP was significantly reduced, following FB procedure compared with prior to FB (P<0.05). No pneumothorax, shock, other severe complications, fever or diffused pneumonia were observed during or after FB. The data from the present study demonstrated that FB is a safe and effective strategy for the diagnosis and differentiation of neonatal respiratory diseases in NICU.