A novel hemizygous CD40L mutation of X-linked hyper IgM syndromes and compound heterozygous DOCK8 mutations of hyper IgE syndromes in two Chinese families.

X-linked hyper-immunoglobulin M (X-HIGM) syndrome and autosomal recessive hyper-immunoglobulin E syndrome (HIES) are rare inborn errors of immunity characterized by recurrent infections due to immune system impairment. In this study, we identified a novel hemizygous CD40 ligand (CD40L) mutation and compound heterozygous dedicator of cytokinesis-8 (DOCK8) mutations in two Han Chinese families with X-HIGM and HIES, respectively. We aimed to investigate the association between their genotypes and phenotypes. Genomic DNA was extracted from peripheral blood samples obtained from the families. Whole exome sequencing and Sanger sequencing were performed to identify and verify pathogenic variants in the two families. Clinical analyses of the probands were also performed. A novel hemizygous mutation of CD40L in exon 2 (c.257delA) was identified in the first proband, resulting in the substitution of glycine with glutamic acid at codon 86 of the protein. This leads to premature termination of translation at downstream codon 9 (p.E86Gfs*9). Sanger sequencing confirmed that the variant was inherited from the mother. The second proband carried two novel compound heterozygous mutations in DOCK8: one at exon 14 (c.1546C > G) inherited from the father, and the other at intron 41 (c.5355 + 6C > T; splicing) inherited from the mother. This study enhances our understanding of the pathogenetic mutation spectrum of CD40L and DOCK8 genes, facilitating the prenatal diagnosis of X-HIGM and HIES and enabling timely treatment of patients.

Diagnostic value of bedside lung ultrasound and 12-zone score in the 65 cases of neonatal respiratory distress syndrome and its severity.

OBJECTIVE: To explore the predictive value of bedside lung ultrasound score in the severity of neonatal respiratory distress syndrome (NRDS) and mechanical ventilation and extubation. METHODS: The clinical data of 65 neonates with NRDS and invasive mechanical ventilation diagnosed in the neonatal intensive care unit of our hospital from July 2021 to July 2022 were retrospectively analyzed. 65 neonates were included in the NRDS group, and 40 neonates with other common lung diseases were selected as the other lung disease groups. All neonates underwent lung ultrasound and X-ray examination. The correlation between lung ultrasound scores and arterial blood gas indexes was analyzed by Pearson. The efficacy of successful evacuation of mechanical ventilation was evaluated by lung ultrasound analysis by ROC curve analysis. RESULTS: The positive rates of lung consolidation and white lung in NRDS group were higher than the other lung disease groups (P < 0.05). The positive rates of bronchial inflation sign and double lung points were lower than these in the other lung disease groups (P < 0.05). The ultrasound scores of both lungs, left lung, right lung, bilateral lung and double basal lung in the NRDS group were significantly higher than those in the other lung disease groups (P < 0.05). There was a significant positive correlation between lung ultrasound score and X-ray grade (r = 0.841, P < 0.001). The area under the curve (AUC) of lung ultrasound score for the differential diagnosis of NRDS and common lung diseases was 0.907. The AUC of lung ultrasound score in the differential diagnosis of mild and moderate, and moderate and severe NRDS were 0.914 and 0.933, respectively, which had high clinical value. The lung ultrasound score was positively correlated with the level of PaCO2 (r = 0.254, P = 0.041), and negatively correlated with the levels of SpO2 and PaO2 (r = - 0.459, - 0.362, P = 0.001, 0.003). The AUC of successful mechanical ventilation withdrawal predicted by the pulmonary ultrasound score before extubation was 0.954 (95% CI 0.907-1.000). The predictive value of successful extubation was 10 points of the pulmonary ultrasound score, with a sensitivity of 93.33% and a specificity of 88.00%. CONCLUSION: The bedside lung ultrasound score can intuitively reflect the respiratory status of neonates, which provides clinicians with an important basis for disease evaluation.

A Case of Fetal Familial Hemophagocytic Lymphohistiocytosis Type 5 caused by STXBP2 Gene Mutation.

BACKGROUND: Familial hemophagocytic lymphohistiocytosis type 5 (FHL-5) is a rare hyper-inflammatory syndrome caused by mutations in STXBP2. Most cases present at 2 - 6 months of age, and FHL-5 is extremely rare in neonates. METHODS: Appropriate laboratory tests, abdominal ultrasonography and whole exome sequencing were carried out. Respiratory support, antibiotics, and transfusion of blood products were done. RESULTS: Laboratory tests revealed metabolic acidosis, thrombocytopenia, mild anemia, and low fibrinogen level. Blood culture, metagenomics, and TORCH screening were negative. Liver and spleen enlargements were confirmed by abdominal ultrasonography. Whole exome sequencing identified a homozygous mutation in STXBP2 c. 1432del G (p. V478Sfs*5). The heterozygous STXBP2 mutation was identified in the paternal grandfather, maternal grandfather, and parents. CONCLUSIONS: Here we report a case with a novel homozygous deletion in exon 16 of STXBP2, which caused the earliest reported case of FHL-5 in a neonate. Our results identify a new pathogenic variant for the early identification and clinical consultation of FHL-5.

Microbial signatures of neonatal bacterial meningitis from multiple body sites.

As a common central nervous system infection in newborns, neonatal bacterial meningitis (NBM) can seriously affect their health and growth. However, although metagenomic approaches are being applied in clinical diagnostic practice, there are some limitations for whole metagenome sequencing and amplicon sequencing in handling low microbial biomass samples. Through a newly developed ultra-sensitive metagenomic sequencing method named 2bRAD-M, we investigated the microbial signatures of central nervous system infections in neonates admitted to the neonatal intensive care unit. Particularly, we recruited a total of 23 neonates suspected of having NBM and collected their blood, cerebrospinal fluid, and skin samples for 2bRAD-M sequencing. Then we developed a novel decontamination method (Reads Level Decontamination, RLD) for 2bRAD-M by which we efficiently denoised the sequencing data and found some potential biomarkers that have significantly different relative abundance between 12 patients that were diagnosed as NBM and 11 Non-NBM based on their cerebrospinal fluid (CSF) examination results. Specifically, we discovered 11 and 8 potential biomarkers for NBM in blood and CSF separately and further identified 16 and 35 microbial species that highly correlated with the physiological indicators in blood and CSF. Our study not only provide microbiological evidence to aid in the diagnosis of NBM but also demonstrated the application of an ultra-sensitive metagenomic sequencing method in pathogenesis study.

Congenital central hypoventilation syndrome in Chinese population: Analysis of three new cases and review of the literature.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant disease that is mainly caused by PHOX2B mutations. The purpose of this study is to analyze and summarize the clinical and genetic characteristics of CCHS patients in the Chinese population from our study and previous literature. METHODS: The potential pathogenic gene mutations of CCHS were identified and verified by next generation sequencing combined with Sanger sequencing, fluorescent probe PCR and capillary electrophoresis. The clinical characteristics and gene mutations of CCHS cases in Chinese population were summarized from our study and previous literature to explore the genotype-phenotype correlations. RESULTS: We identified 48 CCHS cases including three new cases from our report in China. Overall, 77.1% of the patients had PHOX2B polyalanine repeat expansion mutations (PARMs), and the remaining 22.9% had 10 distinct PHOX2B non-polyalanine repeat expansion mutations (NPARMs). Compared to those with PARMs, patients with NPARMs were more likely to have premature birth (54.5% vs. 2.8%, p < 0.001) and lower birth weight (33.3% vs. 3.2%, p = 0.030), with statistical significance. The patients with PARMs were more likely to have cardiovascular defects (64.9% vs. 27.3%, p = 0.063), cerebral hemorrhage (29.7% vs. 9.1%, p = 0.322) and seizures (37.8% vs. 9.1%, p = 0.151) than those with NPARMs, with no statistical significance. CONCLUSIONS: CCHS patients with PHOX2B NPARMs were more likely to have premature birth and low birth weight, while PHOX2B PARMs tended to be positively associated with the risk of cardiovascular defects, cerebral hemorrhage and seizures in Chinese population.

Liver sinusoidal endothelial S1pr2 regulates experimental liver fibrosis through YAP/TGF-ß signaling pathway.

The hepatic vascular niche plays an important role in the pathological process of liver fibrosis. Liver sinusoidal endothelial cells (LSECs) predominantly compose hepatic vascular niches. Endothelial cell (EC)-expressing sphingosine 1-phosphate receptor 2 (S1pr2) plays an essential role in the regulation of vascular functions. Nevertheless, it remains unknown whether liver LSEC-S1pr2 might modulate pathological liver fibrosis. In this study, liver fibrosis was induced by hepatotoxin carbon tetrachloride (CCl4 ). The expression of S1pr2 is significantly downregulated in liver sinusoidal endothelial cells after CCl4 treatment. The loss of S1pr2 in LSECs significantly alleviated liver fibrosis after chronic insult, whereas the overexpression of S1pr2 in LSECs accentuated liver fibrogenesis. In vivo experiments further revealed that the deficiency of S1pr2 in LSECs dampened hepatic stellate cell (HSC) activation, while overexpression of S1pr2 in LSECs enhanced HSC activation with more extracellular matrix component production. Mechanistically, LSEC-S1pr2 activates the YAP signaling pathway to potentiate the transactivation of TGF-ß, which acts on HSCs in a paracrine manner, and thus aggravated liver fibrosis. Taken together, our results uncover a novel pathological mechanism of liver fibrosis in which LSEC-S1pr2 plays an important role in modulating the development of liver fibrosis, providing a future novel therapy target against liver fibrogenesis.

Wnt7b/ß-catenin signaling pathway mediated by retinoid acid involved in the transdifferentiation of primary fetal alveolar epithelial type II cells.

This study was designed to investigate the roles of retinoic acid (RA) in transdifferentiation of primary fetal alveolar epithelial type II cells (AECIIs) into alveolar epithelial type I cells (AECIs). Primary fetal AECIIs isolated from rats at a gestational of 19 days were divided into: (i) DMSO group treated using 0.1% DMSO; (ii) RA group, treated with 1 µM RA; and (iii) RA+BMS493 group treated with 1 µM RA and 10-8 M BMS493 (served as a pan-RA receptor antagonist). Then we determined the roles of AQP5 (a specific marker of AECIs), SP-C (a specific marker for AECIIs) and Wnt7b/ß- catenin signaling pathway in the transdifferentiation of AECIIs to AECIs. SP-C mRNA and protein expression was significantly down-regulated in AECIIs exposure to RA for 24 h and 48 h, however, significant up-regulation was noticed after exposure for 72 h. AQP5 mRNA and protein expression showed significant increase in RA group, but showed significant decline in the RA+BMS493 group. Wnt7b mRNA, nucleus ß-catenin and cyclin D1 were significantly up-regulated in RA group compared with DMSO group. RA may promote fetal AECIIs transdifferentiation into AECIs through activating Wnt7b/ß-catenin signaling pathway. Our study contributed to the understanding on the pulmonary regeneration in cases of pulmonary injuries, together with the prevention and treatment of neonatal respiratory distress syndrome.

Accuracy of magnetic resonance imaging in defining dentate line in anal fistula.

PURPOSE: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in defining dentate line in anal fistula. MATERIALS AND METHODS: Seventy patients with anal fistulas were assessed by dynamic contrast-enhanced MRI. The distance from the dentate line to the anal verge for all patients was measured by MRI. To mitigate interference, 35 patients with anal fistulas whose internal openings were located on the dentate line were excluded from this study. Two observers independently judged the positional relationship between the internal opening and the MRI-defined dentate line, and compared with the results observed by surgeon to assess the accuracy. RESULTS: The distance between the MRI-defined dentate line and the anal verge depended on the location of the internal opening and the morphology of the anal canal mucosa. The distance based on the location the internal opening and the morphology of the anal canal mucosa was 18.2 ± 8.1 mm and 20.0 ± 5.3 mm on oblique coronal T2WI, respectively. Compared with the results observed by the surgeon, the accuracy of evaluating the positional relationship between the internal opening and the dentate line from the morphology of the anal canal mucosa on MRI exceeded 89.9%. Taking 18.2-20.0 mm as the distance between the dentate line and the anal verge on the MRI image, the accuracy of evaluating the relationship between the position of the internal opening and the dentate line was over 85.7%. Considering both the dentate line and the anal canal mucosa, the accuracy of evaluating the relationship between the internal opening and the dentate line was over 91.5%. The results of MRI-defined dentate line were in good agreement with the results of intraoperative surgeon evaluation, and the κ values were 0.70, 0.63, and 0.78, respectively. CONCLUSION: MRI has high accuracy in defining the dentate line in anal fistulas.

Lymphatic endothelial sphingosine 1-phosphate receptor 1 enhances macrophage clearance via lymphatic system following myocardial infarction.

Lymphatic endothelial cell homeostasis plays important roles in normal physiological cardiac functions, and its dysfunction significantly influences pathological cardiac remodeling after myocardial infarction (MI). Our results revealed that sphingosine 1-phosphate receptor 1 (S1pr1) expression in cardiac lymphatic endothelial cells (LECs) was sharply changed after MI. It has been shown that S1pr1 tightly controlled LEC functions and homeostasis. We thus hypothesized that lymphatic endothelial S1pr1 might be involved in post-MI cardiac remodeling. We generated LEC-conditional S1pr1 transgenic mice, in which S1pr1 expression was reduced in cardiac LECs. We performed the left anterior descending coronary artery (LAD) ligation operation to induce MI in these mice. Cardiac functions and remodeling were examined by echocardiography analysis and serial histological analysis. Meanwhile, we performed adoptive cell transfer experiments to monitor macrophage trafficking in post-MI myocardium and their draining lymphatic system. Furthermore, in vitro cell culture experiments and mechanism studies were undertaken to uncover the molecular mechanism by which LEC-S1pr1 regulated cardiac inflammation and remodeling after MI. Our results showed that S1pr1 expression significantly decreased in cardiac LECs after MI. Our in vivo experiments showed that the reduced expression of LEC-S1pr1 deteriorated cardiac function and worsened pathological cardiac remodeling after MI. Our further results demonstrated that the reduced expression of LEC-S1pr1 did not influence macrophage infiltration in an early inflammatory phase of MI, but significantly affected macrophages clearance in the later phase of MI via afferent cardiac lymphatics, and thus influenced inflammatory responses and cardiac outcome after MI. Further study showed that S1P/S1pr1 activated ERK signaling pathway and enhanced CCL2 expression, which promoted macrophage trafficking in a paracrine manner. This study reveals that cardiac lymphatic endothelial cells tightly control macrophage trafficking via lymphatic vessels in injured hearts via S1P/S1pr1/ERK/CCL2 pathway and thus regulate post-MI immune modulation and heart repair. This study highlights the importance of cardiac lymphatic vessel system in orchestrating post-MI immune responses and cardiac remodeling by regulating macrophage transit in injured hearts. Our finding implies that a feasible modulation of S1pr1 signaling in LECs might provide a promising target to resolve excessive inflammation and to ameliorate adverse cardiac remodeling after MI.

Endothelial S1pr2 regulates post-ischemic angiogenesis via AKT/eNOS signaling pathway.

Aims: It is important to understand the mechanism that regulates post-ischemic angiogenesis and to explore a new therapeutic target for an effective improvement of revascularization in peripheral artery disease (PAD) patients. Post-ischemic angiogenesis is a highly orchestrated process, which involves vascular endothelial cells (ECs) proliferation, migration and assembly into capillaries. We found a significant reduction of S1pr2 (sphingosine 1-phosphate receptor 2) in endothelial cells after hindlimb ischemia (HLI). We thus hypothesized that EC-S1pr2 might be involved in the regulation of post-ischemic angiogenesis and blood flow recovery during peripheral arterial disease (PAD). Methods and Results: We generated both EC-specific S1pr2 loss-of-function and S1pr2 gain-of-function mice. Our study showed that EC-specific S1pr2 loss-of-function significantly enhanced post-ischemic angiogenesis and improved blood flow recovery upon femoral artery ligation, whereas the EC-specific S1pr2 gain-of-function severely hindered post-ischemic angiogenesis and reduced blood flow recovery in ischemic limbs. We next identified that S1pr2 inhibited AKT/eNOS signaling pathway, and thus inhibited EC proliferation/migration and angiogenic activity. As expected, pharmacological inhibition of S1pr2 by JTE013 improved post-ischemic angiogenesis and improved blood flow perfusion after femoral artery ligation. Moreover, we developed RGD-peptide magnetic nanoparticles packaging S1pr2-siRNA which specifically targeted ECs and achieved an efficient silencing of S1pr2 expression in ECs in vivo. This EC-targeted strategy to dampen S1pr2 significantly enhanced post-ischemic angiogenesis and boosted blood perfusion after HLI, supplying a novel therapy target for patients with peripheral arterial disease. Conclusions: This present study demonstrates that EC-expressing S1pr2 tightly controls post-ischemic angiogenesis and blood flow perfusion recovery. This research provides a novel strategy for EC-target knockdown of S1pr2 as a new therapeutic intervention for patients with peripheral artery disease.

Initial respiratory support modality and outcome in preterm infants with less than 32 weeks of gestation in China: A multicentre retrospective cohort study.

BACKGROUND: For initial respiratory management, continuous positive airway pressure (CPAP) is increasingly used for preterm infants, especially for gestational age less than 32 weeks. However, neonatologists are concerned about the potential risks of CPAP support failure. OBJECTIVES: To examine the association between different initial respiratory support modalities and the outcomes of preterm infants at <32 weeks of gestation across multiple neonatal intensive care units (NICU) in China. METHODS: This study was carried out over a period of 12 months in 2018. Unadjusted relative risks (RR) for demographic and clinical characteristics were calculated for CPAP failure and CPAP success in the total cohort using log-linear model based on generalised estimating equations for clustered observations. RESULTS: Among 1560 preterm infants delivered at <32 weeks, the incidence of CPAP failure was 10.3%. After adjustment for demographic and clinical factors, the relative risk of mortality (RR 7.54, 95% CI 5.56, 10.44), pneumothorax (RR 9.85, 95% CI 2.89, 61.53), pulmonary haemorrhage (RR 7.78, 95% CI 4.51, 14.64) and BPD (RR 3.65, 95% CI 3.65, 4.51) were considerably higher for infants in the CPAP failure group than those in the CPAP-S group. However, the risk of poor outcomes in CPAP failure infants was similar to that of those in the initial mechanical ventilation (MV) group. CONCLUSIONS: Continuous positive airway pressure failure was associated with an increased risk of mortality and major morbidities, including BPD, pulmonary haemorrhage and pneumothorax, and was comparable to the risk associated with initial MV.

Interleukin-24 as a Pulmonary Target Cytokine in Bronchopulmonary Dysplasia.

The proliferation of fetal alveolar type II cells (FATIICs) was impaired in bronchopulmonary dysplasia (BPD), which is modulated by hyperoxia and inflammatory response. Interleukin 24 (IL-24), a cytokine produced by certain cell types, plays an essential role in inflammation and host protection against infection. However, the ability of FATIICs to produce IL-24 remains unclear, and the role of IL-24 in BPD progression is yet to be determined. With reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay, the authors evaluated whether FATIICs produce IL-24 in physiological conditions. The authors quantified IL-24 expression in the lungs of newborn rat pups exposed to hyperoxia (70% oxygen) and in FATIICs isolated on embryonic day 19 that were exposed to 95% oxygen or lipopolysaccharide (LPS). The role of IL-24 in FATIICs, cell proliferation, cell apoptosis, and cell cycle were further evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometric analysis. Also, they assessed caspase-3 and SOCS3 mRNA in IL-24 siRNA-treated cells by using RT-qPCR. During culture, IL-24 mRNA and protein levels in FATIICs gradually decreased with FATIIC differentiation. IL-24 expression increased significantly in rat lungs exposed to hyperoxia and FATIICs exposed to oxygen or LPS. Recombinant IL-24 enhanced cell proliferation by decreasing the proportion of apoptotic cells and increasing the proportion of cells in the S phase. The IL-24 siRNA-treated cells expressed more caspase-3 mRNA. Furthermore, suppressor of cytokine signaling 3 (SOCS3) mRNA was significantly decreased in rats and FATIICs exposed to oxygen, whereas it dramatically increased in FATIICs exposed to LPS. The IL-24 siRNA-treated cells expressed more SOCS3 mRNA. These studies suggest IL-24 is a pulmonary target cytokine in BPD, and may possibly regulate SOCS3 in oxidative stress and inflammation of the lung.

Vascular endothelial S1pr1 ameliorates adverse cardiac remodelling via stimulating reparative macrophage proliferation after myocardial infarction.

AIMS: Endothelial cell (EC) homoeostasis plays an important role in normal physiological cardiac functions, and its dysfunction significantly influences pathological cardiac remodelling after myocardial infarction (MI). It has been shown that the sphingosine 1-phosphate receptor 1 (S1pr1) was highly expressed in ECs and played an important role in maintaining endothelial functions. We thus hypothesized that the endothelial S1pr1 might be involved in post-MI cardiac remodelling. METHODS AND RESULTS: Our study showed that the specific loss of endothelial S1pr1 exacerbated post-MI cardiac remodelling and worsened cardiac dysfunction. We found that the loss of endothelial S1pr1 significantly reduced Ly6clow macrophage accumulation, which is critical for the resolution of inflammation and cardiac healing following MI. The reduced reparative macrophages in post-MI myocardium contributed to the detrimental effects of endothelial S1pr1 deficiency on post-MI cardiac remodelling. Further investigations showed that the loss of endothelial S1pr1-reduced Ly6clow macrophage proliferation, while the pharmacological activation of S1pr1-enhanced Ly6clow macrophage proliferation, thereby ameliorated cardiac remodelling after MI. A mechanism study showed that S1P/S1pr1 activated the ERK signalling pathway and enhanced colony-stimulating factor 1 (CSF1) expression, which promoted Ly6clow macrophage proliferation in a cell-contact manner. The blockade of CSF1 signalling reversed the enhancing effect of S1pr1 activation on Ly6clow macrophage proliferation and worsened post-MI cardiac remodelling. CONCLUSION: This study reveals that cardiac microvascular endothelium promotes reparative macrophage proliferation in injured hearts via the S1P/S1PR1/ERK/CSF1 pathway and thus ameliorates post-MI adverse cardiac remodelling.

Evaluating postoperative anal fistula prognosis by diffusion-weighted MRI.

PURPOSE: The purpose of this study was to explore whether preoperative diffusion-weighted magnetic resonance imaging (DW-MRI) can be used to evaluate the prognosis of anal fistula and identify the influence factors of postoperative recurrence. METHODS: This is a retrospective study of 117 patients with anal fistula who have undergone preoperative DW-MRI and surgery. All patients were followed up by telephone or reexamination within 2 years after surgery. Of the 117 patients, 35 were excluded due to loss of follow-up and only 82 were included in this study. MRI fistula imaging-related data were analyzed, and fistula severity was scored using criteria of both local extension of fistulas and active inflammation for a total maximum score of 22. The apparent diffusion coefficient (ADC) value of the fistula in patients with anal fistula during preoperative MRI examination was measured. According to whether anal fistula patients are accompanied by perianal abscess, they are divided into two groups, namely anal fistula group and anal fistula with abscess group. Based on whether patients with anal fistula recur after surgery, they were further divided into recurrent group and non-recurrent group. RESULTS: 82 patients with anal fistula were included in this analysis, 23 of them recurred and 59 were cured. Among patients with perianal abscess, the mean ADC value of the recurrent group was (1.19 ±â€¯0.21)×10-3 mm2/s, which is significantly lower than that of the non-recurrent group (1.36 ±â€¯0.19)×10-3 mm2/s. There were significant statistical differences in ADC values between the two groups (p = 0.03). Among patients with anal fistulas without abscesses, 15 patients recurred after surgery, with a mean ADC value of (1.45 ±â€¯0.27) ×10-3 mm2/s, and 33 patients didn't occur, with a mean ADC value of (1.44 ±â€¯0.31)×10-3 mm2/s. The ADC value of preoperative fistula in patients was negative significant correlation with MRI findings score (r= -0.332, P = 0.002). Risk factors for the recurrence after anal fistula surgery include the time interval between MRI and operation, multiple fistula tracks. Fatigue, excessive intake of spicy or greasy food and diarrhea may also be external risk factors for postoperative recurrence of patients with anal fistula. CONCLUSIONS: DW-MRI has important application value for the prognosis evaluation of anal fistula. Complex type of anal fistula and improper lifestyle are the main risk factors affecting the recurrence after anal fistula surgery.

Effects of Different Ligands in the Notch Signaling Pathway on the Proliferation and Transdifferentiation of Primary Type II Alveolar Epithelial Cells.

Background: Transdifferentiation of type II alveolar epithelial cells (AECII) into type I alveolar epithelial cells (AECI) is involved in neonatal respiratory distress syndrome (NRDS). Different ligands of the Notch pathway could have different effects on AECII transdifferentiation. Objective: To investigate the effects of Dlk1 and Jagged1 on the proliferation and transdifferentiation of AECII. Methods: Fetal AECIIs (19 days of gestation) were divided: control group, Dlk1 group, rhNF-κB group. Proliferation was tested using the MTT assay. Expression of surfactant protein C (SP-C) and aquaporin 5 (AQP5) was examined by immunofluorescence. mRNA and protein levels of SP-C, AQP5, Nortch1, Dlk1, Jagged1, and Hes1 were examined by RT-PCR and western blot. Results: In response to Dlk1, cell number and proliferation were increased (P < 0.05), and mRNA and protein levels of SP-C, Dlk1, Notch1, and Hes1 were up-regulated, while AQP and Jagged1 were decreased. In response to rhNF-κB, the cell number and proliferation were reduced, and mRNA and protein levels of Jagged1 and Notch1 were up-regulated, while Dlk1, and SP-C were downregulated. In the Dlk1 group, SP-C, and AQP5 expression patterns suggested that the cells were still transdifferentiating by 96 h, while in the rhNF-κB group, most cells had transdifferentiated by 72 h and were close to apoptosis by 96 h. Conclusion: These results suggest that Dlk1 promoted proliferation of AECIIs and inhibited cell transdifferentiation, while Jagged1 treatment inhibited proliferation of AECIIs and promoted transdifferentiation to AECIs. These results provide some clue for the eventual management of NDRS.

Association between admission hypothermia and outcomes in very low birth weight infants in China: a multicentre prospective study.

BACKGROUND: The objective of this prospective, multicentre, observational cohort study was to evaluate the association between admission hypothermia and neonatal outcomes in very low-birth weight (VLBW) infants in multiple neonatal intensive care units (NICUs) in China. METHODS: Since January 1, 2018, a neonatal homogeneous cooperative research platform-Shandong Neonatal Network (SNN) has been established. The platform collects clinical data in a prospective manner on preterm infants with birth weights (BWs) < 1500 g and gestational ages (GAs) < 34 weeks born in 28 NICUs in Shandong Province. These infants were divided into normothermia, mild or moderate/severe hypothermia groups according to the World Health Organization (WHO) classifications of hypothermia. Associations between outcomes and hypothermia were tested in a bivariate analysis, followed by a logistic regression analysis. RESULTS: A total of 1247 VLBW infants were included in this analysis, of which 1100 infants (88.2%) were included in the hypothermia group, 554 infants (44.4%) in the mild hypothermia group and 546 infants (43.8%) in the moderate/severe hypothermia group. Small for gestational age (SGA), caesarean section, a low Apgar score at 5 min and intubation in the delivery room (DR) were related to admission hypothermia (AH). Mortality was the lowest when their admission temperature was 36.5 ~ 37.5 °C, and after adjustment for maternal and infant characteristics, mortality was significantly associated with AH. Compared with infants with normothermia (36.5 ~ 37.5 °C), the adjusted ORs of all deaths increased to 4.148 (95% CI 1.505-11.437) and 1.806 (95% CI 0.651-5.009) for infants with moderate/severe hypothermia and mild hypothermia, respectively. AH was also associated with a high likelihood of respiratory distress syndrome (RDS), intraventricular haemorrhage (IVH), and late-onset neonatal sepsis (LOS). CONCLUSIONS: AH is still very high in VLBW infants in NICUs in China. SGA, caesarean section, a low Apgar score at 5 min and intubation in the DR were associated with increased odds of hypothermia. Moderate/severe hypothermia was associated with mortality and poor outcomes, such as RDS, IVH, LOS.

Endothelial S1pr1 regulates pressure overload-induced cardiac remodelling through AKT-eNOS pathway.

Cardiac vascular microenvironment is crucial for cardiac remodelling during the process of heart failure. Sphingosine 1-phosphate (S1P) tightly regulates vascular homeostasis via its receptor, S1pr1. We therefore hypothesize that endothelial S1pr1 might be involved in pathological cardiac remodelling. In this study, heart failure was induced by transverse aortic constriction (TAC) operation. S1pr1 expression is significantly increased in microvascular endothelial cells (ECs) of post-TAC hearts. Endothelial-specific deletion of S1pr1 significantly aggravated cardiac dysfunction and deteriorated cardiac hypertrophy and fibrosis in myocardium. In vitro experiments demonstrated that S1P/S1pr1 praxis activated AKT/eNOS signalling pathway, leading to more production of nitric oxide (NO), which is an essential cardiac protective factor. Inhibition of AKT/eNOS pathway reversed the inhibitory effect of EC-S1pr1-overexpression on angiotensin II (AngII)-induced cardiomyocyte (CM) hypertrophy, as well as on TGF-ß-mediated cardiac fibroblast proliferation and transformation towards myofibroblasts. Finally, pharmacological activation of S1pr1 ameliorated TAC-induced cardiac hypertrophy and fibrosis, leading to an improvement in cardiac function. Together, our results suggest that EC-S1pr1 might prevent the development of pressure overload-induced heart failure via AKT/eNOS pathway, and thus pharmacological activation of S1pr1 or EC-targeting S1pr1-AKT-eNOS pathway could provide a future novel therapy to improve cardiac function during heart failure development.

Modelling epidemics with fractional-dose vaccination in response to limited vaccine supply.

The control strategies of emergency infectious diseases are constrained by limited medical resources. The fractional dose vaccination strategy as one of feasible strategies was proposed in response to global shortages of vaccine stockpiles. Although a variety of epidemic models have been developed under the circumstances of limited resources in treatment, few models particularly investigated vaccination strategies in resource-limited settings. In this paper, we develop a two-group SIR model with incorporation of proportionate mixing patterns and n-fold fractional dose vaccination related parameters to evaluate the efficiency of fractional dose vaccination on disease control at the population level. The existence and uniqueness of the final size of the two-group SIR epidemic model, the formulation of the basic reproduction number and the relationship between them are established. Moreover, numerical simulations are performed based on this two-group vector-free model to investigate the effectiveness of n-fold fractional dose vaccination by using the emergency outbreaks of yellow fever in Angola in 2016. By employing linear and nonlinear dose-response relationships, we compare the resulting fluctuations of four characteristics of the epidemics, which are the outbreak size, the peak time of the outbreak, the basic reproduction number and the infection attack rate (IAR). For both types of dose-response relationships, dose-fractionation takes positive effects in lowering the outbreak size, delay the peak time of the outbreak, reducing the basic reproduction number and the IAR of yellow fever only when the vaccine efficacy is high enough. Moreover, five-fold fractional dose vaccination strategy may not be the optimal vaccination strategy as proposed by the World Health Organization if the dose-response relationship is nonlinear.

[Protective effect of interleukin 22 against hyperoxia-induced lung injury in neonatal rats].

Objective To study the protective effect of interleukin-22 (IL-22) against the hyperoxia-induced lung injury in neonatal SD rats. Methods The neonatal SD rats were randomized into control group, hyperoxia group and IL-22 (10 ng/g) treatment group. Each group was randomly divided into three subgroups of 1, 3, 7 days (n=9). Body mass in every group was detected; lung pathological changes were observed by HE staining; tumor necrosis factor α (TNF-α) in lung tissues was tested by quantitative real-time PCR; and IL-1ß in plasma was measured by ELISA. Results After exposure to hyperoxia for 1 day, the body mass in the three groups showed no significant difference, and the structure of lung tissues were normal. After exposure to hyperoxia for 3 or 7 days, the body mass in the hyperoxia group was significantly lower, IL-1ß in plasma was significantly enhanced, and the structure of lung tissues were destroyed, which aggravated with the time of hyperoxia exposure. TNF-α mRNA level increased obviously in the hyperoxia group. However, when treated with IL-22, TNF-α mRNA was significantly down-regulated in the treatment group. Conclusion IL-22 may play an protective role in hyperoxia-induced lung injury.

Breastfeeding Evaluation Indicators System is a Promising Evaluation Tool for Preterm Infants in Neonatal Intensive Care Units (NICU).

BACKGROUND Breast feeding can enhance preterm infants' neurodevelopmental outcome, regulate immune function development. This study aims to develop breastfeeding evaluation indicators system in neonatal intensive care units (NICU) and to provide theoretical basis for all-round evaluation of breast feeding quality for hospitalized preterm infants. MATERIAL AND METHODS This study was performed based on Avedis Donabedian's theory of medical care quality. Preterm infant breast feeding evaluation indicators system frame was initially formed by using literature review, clinical on-spot observation and expert consultation methods. By using specialists meeting method and Delphi method, evaluation indicators system for preterm infants breastfeeding was verified and established. Breastfeeding evaluation indicators system were performed in NICU of hospitals in Binzhou and Shanghai. Feasibility and usability of indicators system were examined. RESULTS Breastfeeding evaluation indicators system for preterm infants comprise 3 levels, including level 1 (3 indicators), level 2 (7 indicators), and level 3 (18 indicators). Recognition rates of importance for level 2 and 3 range from 94.4% to 100.0% and 80.6% to 100.0%, respectively. Mean of Likert rating for level 2 and 3 range from 3.31 to 3.89 and 3.03 to 3.97, which are all higher than the average value of 2.50. Kendall's coefficient and its significance test showed that consistency of experts' opinion for indicators' importance is high (P<0.001). This strategy of combining qualitative and quantitative methods could be used in overall evaluation of the breastfeeding quality in NICUs. CONCLUSIONS Indicators system is feasible and is a promising evaluation tool for continuously improving breastfeeding quality for preterm infants in NICUs.