Objectives To construct prokaryotic expression plasmid of rat surfactant protein C (sp-c) gene under hyperoxia and expression in E.coli. Methods Twenty-one-day-old SD premature rats were exposed to 85%hyperoxia 12 hours after birth. The rats were executed after 7 days and their RNA were extracted from lung and cDNA was synthesized and amplified. And then the cDNA was cloned into pMD18-T vector and confirmed by enzyme digestion and sequencing. After the prokaryotic expression vector pET-28a(+)-sp-c was constructed, the recombinant plasmid was induced by IPTG and expressed in E.coli BL21 strain. The fusion protein was analyzed by SDS-PAGE and Western blotting. Results The pET-28a(+)-sp-c plasmid was constructed and the fusion protein with relative molecule mass of 21000 was highly expressed. Conclusions SP-C is successfully expressed in E. coli, which can be used to study the mechanism of action between SP-C and endoplasmic reticulum, the expression of SP-C in lung epi-thelial cell A549 and the impact of SP-C on proliferation, differentiation and apoptosis of AECIIs in future.

Objectives To investigate the expressions of endoplasmic reticulum stress (ERS)-related factors, glucose regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP), in lungs of rats with bronchopulmonary dysplasia (BPD) and their relationship with pneumonocyte apoptosis, and further to explore the role of ERS-induced apoptosis in the pathogen-esis of BPD. Methods A total of 24 neonatal SD rats were randomly divided into control group and BPD group with 12 rats each. Rats in BPD group were exposed to 85%O2, while rats in the control group were exposed to air. Four rats in each group were sacriifced at 7, 14 and 21 days respectively after exposure. The expression of GRP78 in the lung tissues was examined by immunohistochemistry, the mRNA and protein levels of GRP78 and CHOP were detected respectively by real-time PCR and Western blot, and the apoptosis in lung cells were evaluated by TdT-mediated dUTP nick end labeling (TUNEL) assay. Results The mRNA and protein levels of GRP78 and CHOP, and the cell apoptosis in BPD group were signiifcantly different from those in control group (P<0.01) at different time points and increased over the time of hyperoxic exposure (P<0.01). Conclusions En-doplasmic reticulum stress may be initiated by hyperoxic exposure and apoptosis is induced via CHOP signal pathway, which is involved in the pathogenesis of BPD.

Objective:To study the changes of plasma receptor interacting protein 3 (RIP3) levels in neonatal late-onset sepsis (LOS) and to determine its clinical value.Methods:From October 2019 to April 2021, plasma samples and clinical data of LOS infants admitted to our hospital were prospectively studied. Infants with similar gestational ages admitted for non-infectious diseases were assigned into the control group. Enzyme-linked immunoassay was used to determine plasma RIP3 levels. The clinical value of plasma RIP3 in the diagnosis and treatment of neonatal LOS were analyzed.Results:A total of 152 cases (76 in the LOS group and 76 in the control group) were included in the study. No significant differences existed in the baseline data between the two groups. A total of 226 plasma samples were collected (76 samples from the LOS group before treatment, 74 samples after treatment and 76 samples from the control group). The plasma RIP3 level of LOS group before treatment (19.9±6.3 ng/ml) was significantly higher than the control group (11.4±3.5 ng/ml) and the after treatment group (11.9±3.5 ng/ml) ( P<0.05). The plasma RIP3 level had good diagnostic value for neonatal LOS (AUC=0.884). With cut-off value of 15.5 ng/ml, the plasma RIP3 showed the best diagnostic efficacy (Youden index 0.658, sensitivity 72.4%, specificity 93.4%, positive likelihood ratio 11.0, negative likelihood ratio 0.3). Conclusions:Plasma RIP3 level is closely related with neonatal LOS and may be used for the early diagnosis and therapeutic evaluation of neonatal LOS.

Objective:To study the expression and significance of neutrophil extracellular traps (NETs) in neonatal sepsis.Methods:Prospective research were used in this study. Term infants with neonatal sepsis hospitalized for the first time in the Department of Neonatology, Children's Hospital of Soochow University from June 2020 to November 2020 were selected as the sepsis group. According to a ratio of about 1∶1, term infants with mild hyperbilirubinemia who were admitted in the same period, with gestational age difference less than 1 week from those in the sepsis group, and whose parents agreed to participate in the study were selected as the control group. On admission, clinical data as well as blood samples of the two groups were collected. Levels of NETs marker citrulline histone H3-DNA (CitH3-DNA) were detected by Enzyme-linked immunosorbent assay, and circulating cell-free DNA (cfDNA) was tested by the fluorescence microplate reader. General data, white blood cell (WBC), neutrophil count (NE), platelet (PLT), C- reactive protein (CRP), blood culture, CitH3-DNA and cfDNA were compared between the two groups. The diagnostic value of CITH3-DNA and cfDNA in neonatal septicemia was analyzed by the receiver operating characteristic (ROC) curve.Results:A total of 74 infants were included in the study, including 39 cases in the sepsis group and 35 cases in the control group. CitH3-DNA and cfDNA in the sepsis group were significantly higher than those in the control group [CitH3-DNA (optical density): 0.85±0.05 vs. 0.48±0.03, cfDNA (mg/L): 0.90±0.05 vs. 0.56±0.03] ( P<0.01). There was no significant correlation between CitH3-DNA and cfDNA. The level of CitH3-DNA had no correlation with gender, gestational age, age, birth weight, WBC, NE, PLT and CRP ( P>0.05). cfDNA was positively correlated with age and NE ( P<0.05), and negatively correlated with PLT ( P<0.05). Combined with CRP, the area under the ROC curve of CitH3-DNA+CRP, cfDNA+CRP, and CitH3-DNA+cfDNA+CRP were 0.947, 0.947 and 0.970 respectively, and the sensitivity to predict neonatal sepsis were 92.3%, 84.6% and 94.9% respectively, the specificity were 94.3%, 97.1% and 100% respectively, all higher than the predictive value of each index alone. Conclusions:The plasma NETs levels increase significantly in neonatal sepsis patients, especially CitH3-DNA with a strong specificity, and can be considered as a biomarker for early diagnosis of neonatal sepsis. NETs together with CRP, could drastically improve the predictive value of neonatal sepsis.

Objective:To summarize the clinical characteristics of neonatal late-onset sepsis (LOS) caused by Leclercia adecarboxylata, and provide evidence for its diagnosis and treatment. Methods:We report a case of Leclercia adecarboxylata induced LOS in a male preterm neonate diagnosed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) at the Affiliated Suzhou Hospital of Nanjing Medical University. Relavant literature was retrieved from Wanfang, VIP, CNKI, and PubMed databases up to April 2021, using terms including "neonate" "sepsis" and " Leclercia adecarboxylata". Results:The patient presented with dyspnea immediately after birth with gestational age of 34 +3 weeks and birth weight of 2 050 g. After admission at 14 min after birth, he was incubated at temperature of 33-35 ℃ and humidity of 50%-60% and received active treatment, consisting of nasal continuous positive airway pressure, tracheal intubation, intratracheal injection of pulmonary surfactant, invasive mechanical ventilation, and anti-infective treatment with piperacillin, cefoperazone/sulbactam, and meropenem. However, the patient developed LOS on day 11 of life and eventually died of disseminated intravascular coagulation and multiple organs failure despite volume expansion, anti-infective therapy, and respiratory support. The blood culture was positive for Gram-negative rod and confirmed as a multi-drug resistant strain of Leclercia adecarboxylata. Two cases of LOS caused by sensitive strain of Leclercia adecarboxylata in premature female infants were retrieved in the literature with atypical symptoms, of whom one was successfully treated and one died after active treatment. Conclusions:Leclercia adecarboxylata infection alone can lead to LOS in preterm infants without typical manifestations. MALDI-TOF MS is helpful for the diagnosis and rational application of antibiotics.

Humans ; Aminoquinolines/therapeutic use* ; Carcinoma, Non-Small-Cell Lung/genetics* ; Lung Neoplasms/genetics* ; Mutation/genetics* ; Standard of Care