Reduction of antibiotic use and multi-drug resistance bacteria infection in neonates after improvement of antibiotics use strategy in a level 4 neonatal intensive care unit in southern China.

The investigation on antibiotic stewardship in neonatal intensive care unit in China is scarce. This study aimed to analyze the effect of a comprehensive 2-year antibiotic stewardship in a level 4 NICU. During this baseline period from October 1st 2017 to October 1st 2019, continuation of empirical antibiotic therapy for ruled-out sepsis courses was beyond 72 h and for pneumonia was more than 7 days. Meropenem or vancomycin was used even if they were not the only bacterial sensitive antibiotics. The intervention period was from October 2nd 2019 to August 23rd 2021. Three areas for quality improvement were targeted in our center: discontinuation of antibiotic use in ruled-out sepsis within 72 h, treatment duration for culture-negative pneumonia less than 7 days, and vancomycin or meropenem was not used unless the cultured bacteria was only susceptible to them. The total antibiotic consumption decreased from 791.1 to 466.3 days of therapy per 1000 patient days from baseline to intervention period. Antibiotics were stopped within 72 h for 47.48% patients with rule-out sepsis and within 7 days for 75.70% patients with pneumonia compared with 11.56% and 37.69% during the baseline period respectively. The prevalence of multi-drug resistance bacteria decreased from 67.20 to 48.90%. The total use rate of meropenem or vancomycin decreased from 7.6 to 1.8%. Our quality improvement approach on antibiotic strategy significantly reduced antibiotic use and prevalence of multi-drug resistance bacteria in our NICU.

Cord blood stem cell­derived Angptl7 ameliorates the severity of bronchopulmonary dysplasia via anti­inflammatory and proangiogenic effects.

Perinatal exposure of the neonatal lung to inflammation leads to decreased lung angiogenesis and the development of bronchopulmonary dysplasia (BPD). Notably, autologous cord blood mononuclear cells (ACBMNCs) can substantially prevent severe BPD and decrease the inflammatory response in surviving very preterm neonates. Angiopoietin­like protein 7 (Angptl7) is one of the main paracrine cytokines in cord blood stem cells, and is capable of stimulating human hematopoietic stem and progenitor cell expansion. The present study compared Angptl7 levels between the ACBMNCs infusion and control groups (cohort 1). Subsequently, the association between cord blood Angptl7 levels and BPD incidence in a cohort of very preterm neonates was assessed (cohort 2). The hypothesis was further verified in a lipopolysaccharide (LPS)­induced lung injury mouse model. The mRNA expression levels and protein concentrations of inflammatory cytokines in the lung tissue and mouse serum were measured using reverse transcription­quantitative PCR and ELISA, respectively. The number and diameter of lung vessels and macrophage infiltration were assessed using immunofluorescence staining. Compared with in the control group, Angptl7 levels were significantly higher in the ACBMNCs infusion group in cohort 1. In cohort 2, the cord blood Angptl7 levels were significantly lower in infants who later developed BPD. Multiple linear regression analysis showed that higher Angptl7 level was an independent protective factor for BPD. The concentrations of interleukin­6 and monocyte chemoattractant protein­1 were negatively correlated with cord blood Angptl7 level; whereas, vascular endothelial growth factor­A levels were positively correlated with Angptl7 levels. In the LPS­induced lung injury mouse model, the LPS group presented with a significant loss of pulmonary vessels and smaller vessel diameters, which were ameliorated in the Angptl7 treatment group. Furthermore, LPS­induced lung inflammation and macrophage infiltration were alleviated by Angptl7 treatment (P<0.05). In conclusion, the anti­inflammatory and proangiogenic effects of Angptl7 derived from cord blood stem cells may ameliorate BPD severity. The trial for cohort 1 was registered at ClinicalTrials.gov (trial registration no. NCT02999373; date registered, December 21, 2016).

Dynamics of microbial community composition during degradation of silks in burial environment.

The silk residues in the soil formed the unique niche, termed "silksphere." Here, we proposed a hypothesis that silksphere microbiota have great potential as a biomarker for unraveling the degradation of the ancient silk textiles with great archaeological and conservation values. To test our hypothesis, in this study, we monitored the dynamics of microbial community composition during silk degradation via both indoor soil microcosmos model and outdoor environment with amplicon sequencing against 16S and ITS gene. Microbial community divergence was evaluated with Welch two sample t-test, PCoA, negative binomial generalized log-linear model and clustering, etc. Community assembly mechanisms differences between silksphere and bulk soil microbiota were compared with dissimilarity-overlap curve (DOC) model, Neutral model and Null model. A well-established machine learning algorithm, random forest, was also applied to the screening of potential biomarkers of silk degradation. The results illustrated the ecological and microbial variability during the microbial degradation of silk. Vast majority of microbes populating the silksphere microbiota strongly diverged from those in bulk soil. Certain microbial flora can serve as an indicator of silk degradation, which would lead to a novel perspective to perform identification of archaeological silk residues in the field. To sum up, this study provides a new perspective to perform the identification of archaeological silk residue through the dynamics of microbial communities.

Characteristics of the complete chloroplast genome of Saxifragaceae species Bergenia purpurascens (Hook. f. et Thoms.) Engl.

Bergenia purpurascens (Hook. f. et Thoms.) Engl. is one species of traditional Chinese medicinal plant. This is the first publication of its complete chloroplast (cp) genome. The whole cp genome has 157,246 base pairs in length with 132 annotated genes, of which were 87 protein-coding genes, 37 tRNAs, and 8 rRNAs. According to the phylogenetic study, B. purpurascens and Bergenia scopulosa T. P. Wang. 1974 had a sister relationship. This genomic data and conclusions from B. purpurascens phylogenetic research will provide useful information and throw light on more in-depth investigations of the systematics and evolutionary patterns of Saxifragaceae.

The Correlation of Antibacterial Peptides Concentration in Umbilical Cord Blood and Early Onset Sepsis in Preterm Infants.

Umbilical cord blood from singleton preterm infants was collected during delivery, and the concentration of LL37 was measured. C-reactive protein (CRP), white blood cell count (WBC), platelets (PLT), and mean platelet volume (MPV) were determined within 3 days after birth. The differences in LL37, CRP, WBC, PLT, and MPV levels between the two groups were compared. Pearson correlation method was used to analyze the correlation between these factors. The early individual value of each detected index for early onset sepsis was analyzed by ROC curve. The level of LL37 in umbilical cord blood of sepsis group was significantly higher than those in the control group (383.85 ± 46.71 vs. 252.37 ± 83.30 ng/ml). Meanwhile, the levels of CRP, WBC, and MPV in the sepsis group were significantly higher than those in the control group (CRP:5.73 ± 4.19 vs. 2.50 ± 2.77 mg/L; WBC: 13.47 ± 12.35 vs. 6.83 ± 3.55 × 109/L; MPV: 11.20 ± 1.11 vs. 8.90 ± 0.68 fL), the level of PLT was significantly lower than those in the control group (PLT: 161.00 ± 38.51 vs. 241.50 ± 49.85 × 109/L) (P < 0.05). Pearson correlation analysis showed that the expression of LL37 was negatively correlated with PLT level (r = -0.9347, P < 0.0001), and positively correlated with MPV level (r = 0.9463, P < 0.0001). ROC curve analysis showed that the area under curve of LL37 for diagnosis of early onset sepsis was 0.875, the prediction probability was 0.7, the sensitivity was 90.0% and the specificity was 80.0%.

Cord blood antimicrobial peptide LL37 levels in preterm neonates and association with preterm complications.

BACKGROUND: Cathelicidin/LL-37 plays a significant role in the human immune defense reaction. Preterm human immature organs being exposed to inflammation-induced injury was the critical denominator leading to the common preterm associated complications. Previous study showed LL37 concentration in preterm neonates was lower in tracheal aspirates and breast milk as compared to term infants. An adults study showed decreased LL-37 levels was a risk factor for patients in developing severe chronic obstructive pulmonary disease (COPD). However, little is known about the regulation of human cord blood LL37 in preterm neonates and the association with preterm complications. This study was designed to investigate the concentration of LL37 in cord blood of preterm infants and correlation with preterm complications. METHODS: Singleton infants born in June 2017 to August 2021 in the study hospital were enrolled. Maternal and neonatal clinical characteristics were collected. LL37 levels, pro-inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) in cord blood and LL37 levels in serum 48-72 hours after birth were measured by enzyme-linked immunosorbent assay. The serum level of LL37 in preterm and term neonates were compared, the perinatal factors possibly affecting the LL37 levels were investigated and the relationship between LL37 level and preterm outcomes were analyzed. RESULTS: Cord blood LL37 levels in preterm infants were lower than that in term neonates. Cord blood LL37 level was positively correlated with gestational age in preterm. Prenatal steroid administration in preterm neonates decreased cord blood LL37 level. LL37 level was obviously lower in patients with bronchopulmonary dysplasia (BPD). Multiple line regression analysis showed higher LL37 level in cord blood was an independent protective factor for BPD. The concentration of pro-inflammatory factor IL-6 was negatively correlated with LL37. CONCLUSION: Cord blood LL37 levels increased during gestation and decreased after perinatal steroid usage. Very preterm infants who displayed higher cord blood LL37 level had reduced risk of developing BPD. Regulation of pro-inflammatory cytokine IL-6 may be associated with the protective effect of LL37 on BPD.

Interfacially Locked Metal Aerogel Inside Porous Polymer Composite for Sensitive and Durable Flexible Piezoresistive Sensors.

Flexible pressure sensors play significant roles in wearable devices, electronic skins, and human-machine interface (HMI). However, it remains challenging to develop flexible piezoresistive sensors with outstanding comprehensive performances, especially with excellent long-term durability. Herein, a facile "interfacial locking strategy" has been developed to fabricate metal aerogel-based pressure sensors with excellent sensitivity and prominent stability. The strategy broke the bottleneck of the intrinsically poor mechanical properties of metal aerogels by grafting them on highly elastic melamine sponge with the help of a thin polydimethylsiloxane (PDMS) layer as the interface-reinforcing media. The hierarchically porous conductive structure of the ensemble offered the as-prepared flexible piezoresistive sensor with a sensitivity as high as 12 kPa-1 , a response time as fast as 85 ms, and a prominent durability over 23 000 compression cycles. The excellent comprehensive performance enables the successful application of the flexible piezoresistive sensor as two-dimensional (2D) array device as well as three-dimensional (3D) force-detecting device for real-time monitoring of HMI activities.

Production of chitosan scaffolds by lyophilization or electrospinning: which is better for peripheral nerve regeneration?

Both lyophilization and electrospinning are commonly used to make chitosan scaffolds. However, it remains unknown which method is better for cell growth. In this study, we established the following groups: (1) lyophilization group-chitosan scaffolds were prepared by lyophilization method and seeded with Schwann cells from Sprague-Dawley rats aged 3-5 days; (2) electrospinning group-chitosan scaffolds were prepared by electrospinning method and seeded with Schwann cells; (3) control group-Schwann cells were cultured on culture dishes. The growth of Schwann cells was evaluated by immunofluorescence and scanning electron microscopy. Western blot assay was performed to explore the mechanism of Schwann cell growth. Both materials were non-toxic and suitable for the growth of Schwann cells. The pores produced by electrospinning were much smaller than those produced by lyophilization. The proliferation rate and adhesion rate of Schwann cells in the electrospinning group were higher than those in the lyophilization group. Schwann cells cultured on electrospinning scaffolds formed a Bungner band-like structure, and a much greater amount of brain-derived neurotrophic factor was secreted, which can promote the growth of neurons. Our findings show that the chitosan scaffold prepared by the electrospinning method has a nanofiber structure that provides an extracellular matrix that is more favorable for cell-cell interactions. The electrospinning method is more suitable for nerve regeneration than the lyophilization method. This research was approved by the Medical Ethical Committee of Dalian Medical University (approval No. AEE1-2016-045) on March 3, 2016.

Mesenchymal Stem Cells: Potential Therapeutic Prospect of Paracrine Pathways in Neonatal Infection.

Infection is the leading cause of admission and mortality in neonatal intensive care units. Immature immune function and antibiotic resistance make the treatment more difficult. However, there is no effective prevention for it. Recently, more and more researches are focusing on stem cell therapy, especially mesenchymal stem cells (MSCs); their potential paracrine effect confer MSCs with a major advantage to treat the immune and inflammatory disorders associated with neonatal infection. In this review, we summarize the basal properties and preclinical evidence of MSCs and explore the potential mechanisms of paracrine factors of MSCs for neonatal infection.

Safety and feasibility of umbilical cord blood collection from preterm neonates after delayed cord clamping for the use of improving preterm complications.

BACKGROUND: Umbilical cord blood (UCB) is a new and convenient source of stem cells reported to be safe and effective in preventing and treating preterm complications. The initial processing step for this therapy involves cord blood collection and isolation of the mononuclear cell (MNC) layer. However, there is limited information regarding the feasibility and safety of cord blood collection in preterm infants, and whether cord blood cell quality and quantity are adequate for treating complications in preterm infants. UCB units from preterm infants are currently discarded due to safety concerns regarding collection and owing to the harvesting of inadequate volumes for banking. This study aimed to investigate the feasibility and safety of UCB collection following delayed cord clamping (DCC) for preventing and treating complications in preterm infants. METHODS AND MATERIALS: Singleton preterm infants below 35 weeks gestation were assigned to two cohorts: cord blood collection and non-cord blood collection groups. Mortality and preterm complications in the two groups were compared to evaluate the safety of cord blood collection in preterm infants. The characteristics of the cord blood cells in preterm infants were investigated by comparing the cord blood parameters before and after processing with those of term infants born during the same period. RESULTS: There were 90 preterm infants and 120 term neonates enrolled in this study. Compared to those of the term group, the preterm neonates had significantly less cord blood volume and fewer cell numbers. Nevertheless, the MNC number in the preterm group was 1.92±1.35×108 per kg, which fulfilled the previously reported targeted cell dose (5×107 cells/kg) suitable for application to improve preterm complications. There was no significant difference regarding complications in the preterm neonates with or without cord blood collection. CONCLUSIONS: The collection of UCB after DCC in preterm infants is feasible and safe. The cell numbers and quality fulfill the criteria for use in improving preterm complications. Cord blood MNCs from preterm neonates should be reconsidered as an ideal source for use in stem cell therapy for preterm complications.

The Correlation Between Bronchopulmonary Dysplasia and Platelet Metabolism in Preterm Infants.

Background: Platelets play an important role in the formation of pulmonary blood vessels, and thrombocytopenia is common in patients with pulmonary diseases. However, a few studies have reported on the role of platelets in bronchopulmonary dysplasia. Objective: The objective of the study was to explore the relationship between platelet metabolism and bronchopulmonary dysplasia in premature infants. Methods: A prospective case-control study was performed in a cohort of premature infants (born with a gestational age <32 weeks and a birth weight <1,500 g) from June 1, 2017 to June 1, 2018. Subjects were stratified into two groups according to the diagnostic of bronchopulmonary dysplasia: with bronchopulmonary dysplasia (BPD group) and without bronchopulmonary dysplasia (control group). Platelet count, circulating megakaryocyte count (MK), platelet-activating markers (CD62P and CD63), and thrombopoietin (TPO) were recorded and compared in two groups 28 days after birth; then serial thrombopoietin levels and concomitant platelet counts were measured in infants with BPD. Results: A total of 252 premature infants were included in this study. Forty-eight premature infants developed BPD, 48 premature infants without BPD in the control group who were matched against the study infants for gestational age, birth weight, and admission diagnosis at the age of postnatal day 28. Compared with the controls, infants with BPD had significantly lower peripheral platelet count [BPD vs. controls: 180.3 (24.2) × 109/L vs. 345.6 (28.5) × 109/L, p = 0.001]. Circulating MK count in the BPD group was significantly more abundant than that in the control group [BPD vs. controls: 30.7 (4.5)/ml vs. 13.3 (2.6)/ml, p = 0.025]. The level of CD62p, CD63, and TPO in BPD group was significantly higher than the control group [29.7 (3.1%) vs. 14.5 (2.5%), 15.4 (2.0%) vs. 5.8 (1.7%), 301.4 (25.9) pg/ml vs. 120.4 (14.2) pg/ml, all p < 0.05]. Furthermore, the concentration of TPO was negatively correlated with platelet count in BPD group with thrombocytopenia. Conclusions: Our findings suggest that platelet metabolism is involved in the development of BPD in preterm infants. The possible mechanism might be through increased platelet activation and promoted TPO production by feedback.

Pathological staging of chorioamnionitis contributes to complications in preterm infants.

OBJECTIVE: To investigate the effect of pathological staging of chorioamnionitis (CA) on complications in preterm infants; METHODS: A single-center, retrospective study was conducted to choose singleton preterm infants (gestational age < 37 weeks) from the Department of Obstetrics and Gynecology in our hospital from December 2016 to December 2017. The basic data and placental pathological results were retrospectively collected. According to the placental pathological results of whether inflammation infiltrating amnion, CA 0/I phase was classified into non-amnionitis group, CA II/III phase was classified into amnionitis group, the incidence of common complications in preterm infants was compared. Further, logistic regression was used to analyze the effects of amnionitis on complications after being adjusted to gestational age, birth weight and thrombocytopenia. RESULTS: A total of 221 preterm infants were enrolled, including 186 cases in non-amnionitis group and 35 cases in amnionitis group. The gestational age of amnionitis group (32.00 ± 2.71 weeks) was significantly lower than non-amnionitis group (34.14 ± 2.06 weeks), birth weight (1.93 ± 0.64 kg) was significantly lower than that of non-amnionitis group (2.26 ± 0.58 kg), and the hospital stay in amnionitis group was significantly longer (25.71 ± 19.23 days), all of the difference above was statistically significant(P < 0.05). The incidence of intraventricular hemorrhage (IVH) in amnionitis group (37.14%) was significantly higher than that in non-amnionitis group (13.98%) (P = 0.002), and the risk of IVH was significantly increased by amnionitis (OR = 3.636, 95%CI: 1.632-8.102); after correction of gestational age, birth weight and thrombocytopenia, the risk of IVH was still significantly increased (OR = 2.471, P = 0.046, 95% CI: 1.015-6.015). And the late-onset IVH was more common (P = 0.009). CONCLUSION: Amnionitis leads to a significant reduction in gestational age and birth weight in preterm infants, and it is an independent risk factor for IVH.

Cord Blood Levels of Angiopoietin-Like 7 (ANGPTL7) in Preterm Infants.

OBJECTIVE: ANGPTL7 is a member of the angiogenin-like protein family. Compared to other members, ANGPTL7 is the least known. Recent studies have explored the relationship between ANGPTL7 and multiple pathological processes and diseases. However, there is no research about ANGPTL7 in neonates. This study was designed to investigate the concentration of ANGPTL7 in cord blood of preterm infants. METHOD: Singleton infants born in November 2017 to June 2019 in the study hospital were enrolled in the study. Maternal and neonatal clinical data were collected. ANGPTL7 levels in cord blood and serum on the third day after birth were measured by an enzyme-linked immunosorbent assay. RESULT: A total of 182 infants were enrolled in this study. Patients were categorized into two groups by gestational age (102 preterm, 80 full-term). ANGPTL7 levels in preterm infants were significantly higher than that in full-term babies (t = 15.4, P < 0.001). In multiple line regression analysis, ANGPTL7 levels independently correlated with gestational age (ß = -0.556, P < 0.001). There is also no correlation between preterm outcomes and ANGPTL7 levels. Cord blood levels of ANGPTL7 were significantly higher than those in serum on the third day after birth (t = 13.88, P < 0.001). CONCLUSION: Cord blood ANGPTL7 levels are higher in preterm infants than full-term babies. The levels are independently influenced by gestational ages and attenuated significantly after birth. The underlying mechanism needs to be further studied.

Analysing the structure and glass transition behaviour of silks for archaeology and conservation.

Silk is an iconic material in many cultures. Silk archaeology and conservation is affected by silk production technology as well as subsequent environmental effects such as humidity, temperature, UV radiation and ageing. The complex interactions and various effects on silk materials affect the practical use of silk, for example, in the conservation of ancient manuscripts. This study examines the various influences of silk provenance and processing, adhesive coatings and chemical treatments as well as natural and artificial ageing of the silk material. We use infrared spectroscopy (FTIR) and dynamic mechanical thermal analysis to investigate the glass transition behaviours in a range of archaeological and control silk samples. This allows us to establish structural differences in century-old museum silks and predict the effects of silk ageing and degradation.

[Ultrasonic diagnosis of isolated noncompaction of the ventricular myocardium in adults].

OBJECTIVE: To apply echocardiography in diagnosis of isolated noncompaction of ventricular myocardium (INVM) in adults. METHODS: Six patients with INVM underwent echocardiographic examination using HP5500 ultrasound system with the frequency of 2 approximately equals 4 MHz, and the observation was focused on ventricularmyocardium and endocardium at one-third of the apex. RESULTS: All 6 patients showed typical echocardiographic images characterized by an altered structure of the ventricular myocardium with extremely thickened, hypokinetic segments consisting of two layers: a thin, compacted epicardium and an extremely thickened endocardium, resulting in an extremely thickened ventricular wall. CONCLUSION: Echocardiography should be the first choice to be applied in diagnosis of INVM, which is a distinct entity of specific cardiomyopathy in adults.