Evaluation of disease severity and prediction of severe cases in children hospitalized with influenza A (H1N1) infection during the post-COVID-19 era: a multicenter retrospective study.

BACKGROUND: The rebound of influenza A (H1N1) infection in post-COVID-19 era recently attracted enormous attention due the rapidly increased number of pediatric hospitalizations and the changed characteristics compared to classical H1N1 infection in pre-COVID-19 era. This study aimed to evaluate the clinical characteristics and severity of children hospitalized with H1N1 infection during post-COVID-19 period, and to construct a novel prediction model for severe H1N1 infection. METHODS: A total of 757 pediatric H1N1 inpatients from nine tertiary public hospitals in Yunnan and Shanghai, China, were retrospectively included, of which 431 patients diagnosed between February 2023 and July 2023 were divided into post-COVID-19 group, while the remaining 326 patients diagnosed between November 2018 and April 2019 were divided into pre-COVID-19 group. A 1:1 propensity-score matching (PSM) was adopted to balance demographic differences between pre- and post-COVID-19 groups, and then compared the severity across these two groups based on clinical and laboratory indicators. Additionally, a subgroup analysis in the original post-COVID-19 group (without PSM) was performed to investigate the independent risk factors for severe H1N1 infection in post-COIVD-19 era. Specifically, Least Absolute Shrinkage and Selection Operator (LASSO) regression was applied to select candidate predictors, and logistic regression was used to further identify independent risk factors, thus establishing a prediction model. Receiver operating characteristic (ROC) curve and calibration curve were utilized to assess discriminative capability and accuracy of the model, while decision curve analysis (DCA) was used to determine the clinical usefulness of the model. RESULTS: After PSM, the post-COVID-19 group showed longer fever duration, higher fever peak, more frequent cough and seizures, as well as higher levels of C-reactive protein (CRP), interleukin 6 (IL-6), IL-10, creatine kinase-MB (CK-MB) and fibrinogen, higher mechanical ventilation rate, longer length of hospital stay (LOS), as well as higher proportion of severe H1N1 infection (all P < 0.05), compared to the pre-COVID-19 group. Moreover, age, BMI, fever duration, leucocyte count, lymphocyte proportion, proportion of CD3+ T cells, tumor necrosis factor α (TNF-α), and IL-10 were confirmed to be independently associated with severe H1N1 infection in post-COVID-19 era. A prediction model integrating these above eight variables was established, and this model had good discrimination, accuracy, and clinical practicability. CONCLUSIONS: Pediatric H1N1 infection during post-COVID-19 era showed a higher overall disease severity than the classical H1N1 infection in pre-COVID-19 period. Meanwhile, cough and seizures were more prominent in children with H1N1 infection during post-COVID-19 era. Clinicians should be aware of these changes in such patients in clinical work. Furthermore, a simple and practical prediction model was constructed and internally validated here, which showed a good performance for predicting severe H1N1 infection in post-COVID-19 era.

Successful Conservative Treatment of Necrotizing Pneumonia in Pediatric Patients: Two Case Reports.

Objective: Necrotizing pneumonia is a rare and serious complication in pediatric patients, and its treatment often involves the complexity of choosing between surgical intervention and medical management. The disease is difficult to treat because of its devastating characteristics and high mortality rate, especially when considering the risks associated with surgery. The purpose of this report is to present two cases of necrotizing pneumonia in pediatric patients and demonstrate successful conservative management to provide additional insights for clinical decision-making. Case Report: We report two pediatric patients, aged 3 years 7 months and 7 years respectively, who presented with varying degrees of clinical symptoms, including persistent high fever, shortness of breath, and were confirmed to have necrotizing pneumonia after thorough diagnosis and underwent a period of intensive care. Weeks of treatment. Both patients received long-term antibiotic therapy, ventilator support, and analgesia. Conservative management including type of antibiotics, duration of treatment, specific parameters of respiratory support, and analgesic medications is detailed. Conclusion: Our case report highlights that necrotizing pneumonia can be successfully treated with conservative treatment, thus obviating the need for early surgical intervention. These findings are potentially important for guiding clinical practice, suggesting that conservative management can be an effective treatment strategy for necrotizing pneumonia in certain circumstances.

Evaluation of febrile seizures in children infected with SARS-CoV-2 Omicron variant in Yunnan, China: a multi-center, retrospective observational study.

Background: The SARS-CoV-2 Omicron variant was reported to be linked to febrile seizures (FSs), but studies on FSs in children with Omicron infection remain relatively scarce, especially in the Chinese population. This study aimed to investigate the characteristics of children diagnosed with Omicron infection with FSs in Yunnan, China, and evaluate the potential association between FSs and Omicron infection. Methods: This study was conducted at four hospitals in Yunnan from December 8, 2022, to January 8, 2023, and consisted of 590 pediatric subjects. According to clinical characteristics, 85, 129 and 376 subjects were divided into the FS-only, Omicron-FS, and Omicron-only groups, respectively. Demographic, clinical and laboratory data were retrospectively collected for analysis. Results: The incidence of FSs in children with Omicron infection was 25.5% (129/505). Older age, stronger male predominance, as well as lower proportions of prior history and family history of seizures were observed in Omicron-FS and Omicron-only groups than in FS-only group, but there were no differences in these four above-mentioned events between these two Omicron-related groups. Compared to FS-only group, Omicron-FS group also had a shorter fever-to-seizure onset duration and more frequent seizures during a single course of fever. Moreover, higher levels of IL-6, TNF-α and ferritin as well as decreased counts of leukocytes and lymphocytes were confirmed in Omicron-FS group than in FS-only and Omicron-only groups. Regarding COVID-19 vaccination status, Omicron-FS group revealed a higher proportion of unvaccinated children and a lower proportion of three-dose vaccination than Omicron-only group. As for clinical outcomes, proportions of mechanical ventilation and intensive care unit admission observed in the two Omicron-related groups were notably higher than those in FS-only group. Meanwhile, Omicron-FS group showed the longest length of hospital stay, followed by Omicron-only group and FS-only group, in order. Finally, all patients but one who died of fulminant myocarditis had been successfully discharged. Conclusions: The incidence of FSs in children with Omicron infection was 25.5% in Yunnan. FSs might be a clinical sign deserving more attention in children with Omicron infection. Furthermore, COVID-19 vaccination is likely to provide effective protection against Omicron-related FSs in children.

Development and validation of a risk prediction model for early diabetic peripheral neuropathy based on a systematic review and meta-analysis.

Background: Early identification and intervention of diabetic peripheral neuropathy is beneficial to improve clinical outcome. Objective: To establish a risk prediction model for diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM). Methods: The derivation cohort was from a meta-analysis. Risk factors and the corresponding risk ratio (RR) were extracted. Only risk factors with statistical significance were included in the model and were scored by their weightings. An external cohort were used to validate this model. The outcome was the occurrence of DPN. Results: A total of 95,604 patients with T2DM from 18 cohorts were included. Age, smoking, body mass index, duration of diabetes, hemoglobin A1c, low HDL-c, high triglyceride, hypertension, diabetic retinopathy, diabetic kidney disease, and cardiovascular disease were enrolled in the final model. The highest score was 52.0. The median follow-up of validation cohort was 4.29 years. The optimal cut-off point was 17.0, with a sensitivity of 0.846 and a specificity of 0.668, respectively. According to the total scores, patients from the validation cohort were divided into low-, moderate-, high- and very high-risk groups. The risk of developing DPN was significantly increased in moderate- (RR 3.3, 95% CI 1.5-7.2, P = 0.020), high- (RR 15.5, 95% CI 7.6-31.6, P < 0.001), and very high-risk groups (RR 45.0, 95% CI 20.5-98.8, P < 0.001) compared with the low-risk group. Conclusion: A risk prediction model for DPN including 11 common clinical indicators were established. It is a simple and reliable tool for early prevention and intervention of DPN in patients with T2DM.

Development and validation of a risk prediction model for the recurrence of foot ulcer in type 2 diabetes in China: A longitudinal cohort study based on a systematic review and meta-analysis.

AIMS: To develop and validate a risk prediction model for Chinese patients with type 2 diabetes with the recurrence of diabetic foot ulcers (DFUs) based on a systematic review and meta-analysis. METHODS: A prospective analysis was performed with 1333 participants and followed up for 60 months. Three models were analysed using a derived cohort. The risk factors were screened using meta-analysis and logistic regression, and the missing variables were interpolated by multiple imputation. The internal validation was performed using the bootstrap procedure, and the validation cohort was applied to the external validation. The performance of the model was evaluated in the area under the discrimination Receiver Operating Characteristic Curve (ROC). Calibration and discrimination methods were used for the validation cohort. The variables were selected according to their clinical and statistical importance to construct the nomograms. RESULTS: Three models were developed and validated. Model 1 included seven social and clinical indicators like sex, diabetes mellitus duration, previous DFU, location of ulcer, smoking, history of amputation, and foot deformity. Model 2 included four more indicators besides those in Model 1, which were statin agents used, antiplatelet agents used, systolic blood pressure, and body mass index. Model 3 added further laboratory indicators to Model 2, such as LDL-C, HbA1C, fibrinogen, and blood urea nitrogen. In the derivation cohort, 20.1% (206/1027) participants with DFU recurred as compared to the validation cohort, which was 38.2% (117/306). The areas under the curve in the derivation cohort for Models 1-3 were 0.781 (0.744-0.817), 0.843 (0.813-0.873), and 0.899 (0.876-0.922), respectively. The Youden indexes for Models 1-3 were 0.430, 0.559, and 0.653, respectively. Model 3 showed the highest sensitivity and specificity. All models performed well for both discrimination and calibration. CONCLUSIONS: Models 1-2 were non-invasive, which indicate their role in general screening for patients at a high risk of recurrence of DFU. However, Model 3 offers a more specific screening due to its best performance in predicting the risk of DFU recurrence amongst the three models.

A novel de novo heterozygous variant of the KCNQ2 gene: Contribution to early­onset epileptic encephalopathy in a female infant.

Early­onset epileptic encephalopathy (EOEE) represents one of the most severe epilepsies, characterized by recurrent seizures during early infancy, electroencephalogram (EEG) abnormalities and varying degrees of neurodevelopmental delay. The KCNQ2 gene has been reported to have a major role in EOEE. In the present study, a 3­month­old female infant from the Chinese Lisu minority with EOEE was analyzed. Detailed clinical evaluations and next­generation sequencing were performed to investigate the clinical and genetic characteristics of this patient, respectively. Furthermore, the three­dimensional structure of the mutant protein was predicted by SWISS­Model and the expression of KCNQ2 protein in the patient was assessed by flow cytometry. It was observed that the patient presented with typical clinical features of EOEE, including repeated non­febrile seizures and significant EEG abnormalities. A novel heterozygous missense variant c.431G>C (p.R144P) in KCNQ2 was identified in the patient and the genotyping of KCNQ2 in the patient's parents suggested that this variant was de novo. Subsequently, the breakage of hydrogen bonds between certain amino acids was predicted by structural analysis of the mutant protein. Flow cytometric analysis detected a significant reduction buts not complete loss of native KCNQ2 protein expression in the patient (25.1%). In conclusion, a novel variant in KCNQ2 was confirmed as the genetic cause for EOEE in this patient. The present study expanded the pathogenic mutation spectrum of KCNQ2, enhanced the understanding of the molecular pathogenesis of EOEE and provided novel clues for research on the genotype­phenotype correlation in this disease.

Glycemic Variability Is Independently Associated With Poor Prognosis in Five Pediatric ICU Centers in Southwest China.

Background: Glucose variability (GV) is a common complication of dysglycemia in critically ill patients. However, there are few studies on the role of GV in the prognosis of pediatric patients, and there is no consensus on the appropriate method for GV measurement. The objective of this study was to determine the "optimal" index of GV in non-diabetic critically ill children in a prospective multicenter cohort observational study. Also, we aimed to confirm the potential association between GV and unfavorable outcomes and whether this association persists after controlling for hypoglycemia or hyperglycemia. Materials and Methods: Blood glucose values were recorded for the first 72 h and were used to calculate the GV for each participant. Four different metrics [SD, glycemic lability index (GLI), mean absolute glucose (MAG), and absolute change of percentage (ACACP)] were considered and compared to identify the "best" GV index associated with poor prognosis in non-diabetic critically ill children. Among the four metrics, the SD was most commonly used in previous studies, while GLI- and MAG-integrated temporal information, that is the rate and magnitude of change and the time interval between glucose measurements. The fourth metric, the average consecutive ACACP, was introduced in our study, which can be used in real-time clinical decisions. The primary outcome of this study was the 28-day mortality. The receiver operating characteristic (ROC) curve analysis was conducted to compare the predictive power of different metrics of GV for the primary outcome. The GV index with the largest area under ROC curve (AUC) was chosen for subsequent multivariate analyses. Multivariate Cox regression analysis was performed to identify the potential predictors of the outcome. To compare the contribution in 28-day mortality prognosis between glycemic variability and hyper- or hypoglycemia, performance metrics were calculated, which included AUC, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results: Among 780 participants, 12.4% (n = 97) died within 28 days after admission to the pediatric intensive care unit (PICU). Statistically significant differences were found between survivors and non-survivors in terms of four GV metrics (SD, GLI, MAG, and ACACP), in which MAG (AUC: 0.762, 95% CI: 0.705-0.819, p < 0.001) achieved the largest AUC and showed a strong independent association with ICU mortality. Subsequent addition of MAG to the multivariate Cox model for hyperglycemia resulted in further quantitative evolution of the model statistics (AUC = 0.651-0.681, p = 0.001; IDI: 0.017, p = 0.044; NRI: 0.224, p = 0.186). The impact of hyperglycemia (adjusted hazard ratio [aHR]: 1.419, 95% CI: 0.815-2.471, p = 0.216) on outcome was attenuated and no longer statistically relevant after adjustment for MAG (aHR: 2.455, 95% CI: 1.411-4.270, p = 0.001). Conclusions: GV is strongly associated with poor prognosis independent of mean glucose level, demonstrating more predictive power compared with hypoglycemia and hyperglycemia after adjusting for confounding factors. GV metrics that contain information, such as time and rate of change, are the focus of future research; thus, the MAG may be a good choice. The findings of this study emphasize the crucial role of GVs in children in the PICU. Clinicians should pay more attention to GV for clinical glucose management.

[Pulmonary ventilation function parameters of children aged 5-14 years in Kunming, China: a comparative analysis of measured values versus predicted values based on Zapletal equation].

OBJECTIVE: To study the percentage of the measured values of the main pulmonary ventilation function parameters in their predicted values based on Zapletal equation among healthy children aged 5-14 years in Kunming, China, and to provide a basis for accurate judgment of pulmonary ventilation function in clinical practice. METHODS: A total of 702 healthy children aged 5-14 years (352 boys and 350 girls) from Kunming were enrolled. The Jaeger spirometer was used to measure the nine indices:forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), maximal mid-expiratory flow (MMEF), forced expiratory flow at 25% of forced vital capacity (FEF25), forced expiratory flow at 50% of forced vital capacity (FEF50), forced expiratory flow at 75% of forced vital capacity (FEF75), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV). The values obtained from the Zapletal equation of predicted values provided by the spirometer were used as the predicted values of children, and the percentage of measured values in predicted values was calculated. RESULTS: In the 702 children, the percentages of the measured values of the main pulmonary ventilation function parameters PEF, FVC, FEV1, FEV1/FVC, and MVV in their predicted values fluctuated from 102% to 114%, 94% to 108%, 98% to 113%, 98% to 107%, and 141% to 183% respectively. As for the main airway velocity parameters, the percentages of the measured values of FEF25, FEF50, FEF75, and MMEF in their predicted values fluctuated from 98% to 116%, 85% to 102%, 71% to 98%, and 83% to 100% respectively. The percentages of the measured values of PEF, FVC, FEV1, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in their predicted values had the lower limits of normal of 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively. CONCLUSIONS: There are differences between pulmonary ventilation function parameter levels and normal values provided by Zapletal equation in healthy children aged 5-14 years in Kunming. As for the pulmonary ventilation function parameters of PEF, FVC, FEV, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in these children, the lower limits of normal of measured values in predicted values may be determined as 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively.

Calcitonin gene-related peptide protects type II alveolar epithelial cells from hyperoxia-induced DNA damage and cell death.

Hyperoxia therapy for acute lung injury (ALI) may unexpectedly lead to reactive oxygen species (ROS) production and cause additional ALI. Calcitonin gene-related peptide (CGRP) is a 37 amino acid neuropeptide that regulates inflammasome activation. However, the role of CGRP in DNA damage during hyperoxia is unclear. Therefore, the aim of the present study was to investigate the effects of CGRP on DNA damage and the cell death of alveolar epithelial type II cells (AEC II) exposed to 60% oxygen. AEC II were isolated from 19-20 gestational day fetal rat lungs and were exposed to air or to 60% oxygen during treatment with CGRP or the specific CGRP receptor antagonist CGRP8-37. The cells were evaluated using immunofluorescence to examine surfactant protein-C and ROS levels were measured by probing with 2',7'-dichlorofluorescin diacetate. The apoptosis rate and cell cycle of AEC II were analyzed by flow cytometry, and apoptosis was determined by western blotting analysis of activated caspase 3. The DNA damage was confirmed with immunofluorescence of H2AX via high-content analysis. The ROS levels, apoptotic cell number and the expression of γH2AX were markedly increased in the hyperoxia group compared with those in the air group. Concordantly, ROS levels, apoptotic cell number and the expression of γH2AX were significantly lower with a significant arrest of S and G2/M phases in the CGRP/O2 group than in the hyperoxia or CGRP8-37/O2 groups. CGRP was concluded to protect lung epithelium cells against hyperoxic insult, and upregulation of CGRP may be a possible novel therapeutic target to treat hyperoxic lung injury.

[The proliferation-promoting effects of calcitonin gene-related peptide on type II alveolar epithelial cell exposed to hyperoxia mediated by protein kinase C alpha pathway].

OBJECTIVE: To explore the effects of calcitonin gene-related peptide (CGRP) on type II alveolar epithelial cell (AECII) exposed to hyperoxia, and to determine whether the mechanism is mediated by protein kinase C alpha/nuclear factor-KappaB (PKC alpha/NF-KappaB) signal pathway. METHODS: AECII were isolated from the lung of 21 days fetal rat and cultured for 15 hours to coalesce. Then AECII were randomly assigned into four groups: air, hyperoxia, O(2)/CGRP, and O(2)/CGRP8-37 (a receptor antagonist against CGRP). AECII were exposed to FiO(2) 21% (air) or 85% (hyperoxia) for 24 hours respectively. In O(2)/CGRP and O(2)/CGRP8-37 groups CGRP or both CGRP and CGRP8-37 were added into cultural fluid before placing the plate into 85% oxygen. Cell proliferation ability was determined by methyl thiazolyl tetrazolium (MTT) assay and cell cycles by flow cytometry. Western blotting was employed to detect the fraction of PKC alpha in membrane and cytosol, and translocation of NF-KappaB was observed under laser confocal microscopy. RESULTS: AECII in hyperoxia group showed a decreased viability of AECII [(68.752+/-5.766)% vs. (100.000+/-6.682)%] and had an enhanced percentage of G0/G1 phase [(80.652+/-6.253)% vs. (45.825+/-2.899)%] with a corresponding decline in percentage of S phase [(14.198+/-4.785)% vs. (27.470+/-2.775)%] and G2/M phases [(5.148+/-1.688)% vs. (26.708+/-1.863)%] compared with AECII in air (all P<0.01). Addition with CGRP before hyperoxia exposure promoted AECII proliferation [(94.813+/-6.102)%] and enhanced the cell proportions in S and G2/M phases [(30.547+/-9.861)% and (17.668+/-9.509)%, all P<0.01]. The ratio of membrane to cytoplasm fraction of PKC alpha declined (0.63+/-0.10 vs. 1.00+/-0.09) and the fluorescence of NF-KappaB in nucleus enhanced (22.98+/-2.20 vs. 14.54+/-2.35) in hyperoxia compared with that in air, while both the ratio of PKC alpha and intensity of NF-KappaB were increased in O(2)/CGRP group (1.41+/-0.23, 35.38+/-3.37) compared with those in hyperoxia (0.63+/-0.10, 22.98+/-2.20) and O(2)/CGRP8-37 groups (0.74+/-0.10, 24.88+/-1.81, all P<0.01). CONCLUSION: CGRP could promote proliferation of AECII when exposed to high oxygen tension. PKC alpha participates in the signal transduction process and NF-KappaB is a downstream molecular of PKC alpha, executing in part the function of PKC alpha signal.

Neuropeptide substance P attenuates hyperoxia-induced oxidative stress injury in type II alveolar epithelial cells via suppressing the activation of JNK pathway.

Hyperoxia-induced oxidative stress plays a key role in many pulmonary diseases. In an earlier study we found the protective effect of the neuropeptide substance P (SP) on type II alveolar epithelial cells (AECIIs) after hyperoxia exposure. Then, we investigated c-Jun N-terminal kinase (C-JNK) signal transduction pathways in AECIIs before and after hyperoxia exposure. Primary AECIIs were isolated and purified from premature rats. Subsequently, the cells were treated with air (21% oxygen), hyperoxia (95% oxygen), SP+ air, and SP+ hyperoxia. SP was added in advance to reach a final concentration 1 x 10(-6) mol/l. The cells were then exposed to air and hyperoxia for 12, 24, and 48 h. XTT cell proliferation assay and fluorescence-activated cell sorting (FACS) were employed to detect cell growth and apoptosis. Phosphorylated JNK (p-JNK) levels were measured using Western blot assay. The morphological alteration of AECIIs was observed using a transmission electron microscope (TEM). Compared with the simple hyperoxia treatment, the cell growth and apoptosis percentage was significantly increased and decreased after adding additional SP. Meanwhile, the reduced levels of p-JNKs could be found after adding SP. Furthermore, the morphological damage of AECIIs was greatly improved. These data suggest that SP can promote AECII proliferation and inhibit apoptosis by suppressing JNK signal pathways after hyperoxia exposure, which attenuates hyperoxia-induced oxidative stress damage in AECIIs. It might be a potential therapy for acute pulmonary injury under hyperoxia-induced oxidative stress.

[Influence of 60% oxygen inhalation on type II alveolar epithelial cells and protective role of calcitonin gene-related peptide from their damage induced in premature rat].

OBJECTIVE: To study in vitro the influence of 60% oxygen and the protective effect of calcitonin gene-related peptide (CGRP) on type II alveolar epithelial cells (AEC II) isolated from the lung of premature rat. METHODS: AEC II were isolated from the lung of 19-day rat fetus, and they were then cultured in six-well plates. The cells were randomly divided into four groups: air group, hyperoxia group, hyperoxia plus CGRP group, hyperoxia plus CGRP and CGRP8-37 (CGRP receptor antagonist) group. Cells of air group and hyperoxia group were exposed to 21% air or 60% oxygen, respectively, while in hyperoxia plus CGRP group CGRP was added, and in hyperoxia plus CGRP and CGRP8-37 group CGRP and CGRP8-37 were added before exposure to 60% oxygen. Cells in four groups were cultured for 24 hours, and then ground into homogenates for detection of malondialdehyde (MDA), total antioxidant capacity (TAOC) and superoxide dismutase (SOD) with ultraviolet spectrophotometer. Reactive oxygen species (ROS) and apoptosis rate of AEC II were analyzed by flow cytometry and the mRNA level of surfactant associated protein C (SPC) was measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The levels of ROS, MDA and apoptosis rate were increased whereas TAOC, SOD and SPC mRNA expression declined in hyperoxia group compared with those in air group (all P<0.01). In contrast, MDA, ROS and apoptosis rate were significantly lower and levels of TAOC, SOD and SPC mRNA expression were significantly higher in hyperoxia plus CGRP group than those in hyperoxia group (all P<0.01). The differences in 6 parameters above between hyperoxia group and hyperoxia plus CGRP and CGRP8-37 group were not statistically significant. CONCLUSION: Exposure of AEC II from immature rat to 60% oxygen for 24 hours may produce oxidative injury, inducing apoptosis and decrease in SPC mRNA level of AEC II of premature rat in vitro, while CGRP may play a protective role against hyperoxic lung injury by its antioxidant property, and also inhibition of AEC II apoptosis and promotion of the SPC mRNA expression.