This study aims to investigate the effects of the skin tissue derived peptides on proliferation, apoptosis, migration and collagen expressions in keloid fibroblasts. From January 2015 to January 2017, patients with hypertrophic scar who underwent surgical excision in department of plastic surgery of Nanjing maternal and child health hospital were included in this retrospective study. Four peptides were selected from the differential peptides between human hypertrophic scar and normal skin tissue. They were named as peptide deregulated in hypertrophic scar 2-5 (PDHPS2-5). Bioinformatics and functional analysis were performed. A low dose of 10 μmol/L of four peptides were respectively added to the culture medium of human primary keloid fibroblasts for 24 h. Cell counting kit-8 (CCK-8) were used to detect the changes in cell viability. Cell apoptosis was detected by flow cytometry. Cell migration ability was checked by Transwell chamber. The protein expressions of collagen COL1A2 (Collagen type I alpha 2) and the myofibroblast marker gene ACTA2 (Actin alpha 2) were analyzed by Western blot. The results showed that bioinformatics prediction analysis revealed that peptide PDHPS4 has the longest half-life and the highest thermal stability. Compared with the control group, low dose of four peptides had no significant effect on the survival rate and apoptosis of keloid fibroblasts tested by CCK-8 assay and flowcytometry. Transwell analysis showed that one peptides (PDHPS5) can significantly inhibit the cell migration ability (The optical density value in Control is 0.81±0.11, in PDHPS5 is 0.27±0.03, t=8.61, P=0.001). Western blot analysis showed that four peptides (PDHPS2, PDHPS3, PDHPS4, PDHPS5) can significantly inhibit the protein expressions of COL1A2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.21±0.04, in PDHPS3 is 0.26±0.03, in PDHPS4 is 0.53±0.04, in PDHPS5 is 0.73±0.04, t=31.38, 38.54, 18.88, 11.07 respectively, all P value are less than 0.01). Three peptides (PDHPS2, PDHPS3, PDHPS5) can significantly inhibit the protein expressions of ACTA2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.64±0.05, in PDHPS3 is 0.77±0.06, in PDHPS5 is 0.47±0.07, t=12.08, 6.38, 14.06 respectively, all P value are less than 0.01). In conclusion, the differentially expressed peptides in human hypertrophic scar tissue can affect the function of keloid fibroblasts and collagen expressions to varying degrees. Among them, two peptides (PDHPS2,PDHPS3) significantly inhibit the protein expressions of COL1A2 and ACTA2. The peptide PDHPS5 has high stability, significantly suppresses cell migration, and reduces the protein expressions of COL1A2 and ACTA2, which may provide a new strategy for scar prevention and treatment.

This study aims to investigate the effects of the skin tissue derived peptides on proliferation, apoptosis, migration and collagen expressions in keloid fibroblasts. From January 2015 to January 2017, patients with hypertrophic scar who underwent surgical excision in department of plastic surgery of Nanjing maternal and child health hospital were included in this retrospective study. Four peptides were selected from the differential peptides between human hypertrophic scar and normal skin tissue. They were named as peptide deregulated in hypertrophic scar 2-5 (PDHPS2-5). Bioinformatics and functional analysis were performed. A low dose of 10 μmol/L of four peptides were respectively added to the culture medium of human primary keloid fibroblasts for 24 h. Cell counting kit-8 (CCK-8) were used to detect the changes in cell viability. Cell apoptosis was detected by flow cytometry. Cell migration ability was checked by Transwell chamber. The protein expressions of collagen COL1A2 (Collagen type I alpha 2) and the myofibroblast marker gene ACTA2 (Actin alpha 2) were analyzed by Western blot. The results showed that bioinformatics prediction analysis revealed that peptide PDHPS4 has the longest half-life and the highest thermal stability. Compared with the control group, low dose of four peptides had no significant effect on the survival rate and apoptosis of keloid fibroblasts tested by CCK-8 assay and flowcytometry. Transwell analysis showed that one peptides (PDHPS5) can significantly inhibit the cell migration ability (The optical density value in Control is 0.81±0.11, in PDHPS5 is 0.27±0.03, t=8.61, P=0.001). Western blot analysis showed that four peptides (PDHPS2, PDHPS3, PDHPS4, PDHPS5) can significantly inhibit the protein expressions of COL1A2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.21±0.04, in PDHPS3 is 0.26±0.03, in PDHPS4 is 0.53±0.04, in PDHPS5 is 0.73±0.04, t=31.38, 38.54, 18.88, 11.07 respectively, all P value are less than 0.01). Three peptides (PDHPS2, PDHPS3, PDHPS5) can significantly inhibit the protein expressions of ACTA2 (The relative protein band intensity in Control is 1.02±0.02, in PDHPS2 is 0.64±0.05, in PDHPS3 is 0.77±0.06, in PDHPS5 is 0.47±0.07, t=12.08, 6.38, 14.06 respectively, all P value are less than 0.01). In conclusion, the differentially expressed peptides in human hypertrophic scar tissue can affect the function of keloid fibroblasts and collagen expressions to varying degrees. Among them, two peptides (PDHPS2,PDHPS3) significantly inhibit the protein expressions of COL1A2 and ACTA2. The peptide PDHPS5 has high stability, significantly suppresses cell migration, and reduces the protein expressions of COL1A2 and ACTA2, which may provide a new strategy for scar prevention and treatment.

In order to facilitate technical personnel related to occupational health and safety production to search, obtain, and master information on the hazard classification and health effects of chemical hazards, this article surveyed 14 commonly used foreign databases and 9 commonly used domestic databases, analyzed the characteristics, main content, scope of application, and network resources of each database, and considered the development of database for occupational health hazard of chemical hazards.

In order to facilitate technical personnel related to occupational health and safety production to search, obtain, and master information on the hazard classification and health effects of chemical hazards, this article surveyed 14 commonly used foreign databases and 9 commonly used domestic databases, analyzed the characteristics, main content, scope of application, and network resources of each database, and considered the development of database for occupational health hazard of chemical hazards.

ObjectiveTo establish a method using ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS） for the detection of six common trichothecene toxins in oats. MethodsOats were selected as the research subject in this study. Response surface design was used to optimize the QuEChERS extraction method. Additionally， a rapid and efficient strategy for sample extraction and purification was developed. Combined with UHPLC-MS/MS， six commonly co-occurring trichothecene toxins in oats were quantitatively analyzed simultaneously. ResultsThis method demonstrated good analytical performance for each analyte across the corresponding concentration ranges （r>0.99）， with accuracy ranging from 87.26% to 99.64%. The inter-day and intra-day relative standard deviations were less than 6.8% and 5.5%， respectively， indicating its potential for practical application. This method was used to detect mycotoxins in 12 oat samples from China， and it was found that one sample exceeded the standard limits for deoxynivalenol （DON）， and the co-contamination of trichothecene toxin was prevalent. ConclusionThe risk posed by these toxins has been underestimated. Ongoing， extensive monitoring is necessary to provide contamination data to assess the consumer risk.

BACKGROUND:Osteonecrosis of the femoral head is a common orthopedic disease,and hip preservation surgery with bone grafting is commonly used in the early stage,in which autologous bone and allograft bone are commonly used as bone grafting materials.However,autologous bone transplantation is highly traumatic and bone supply is limited,and allograft bone is rich in sources,but there are serious risks of immune rejection and absorption.In recent years,the tissue engineering technique based on mesenchymal stem cells is a new method for the treatment of femoral head necrosis,which is gradually widely used after basic experiments and clinical application. OBJECTIVE:To review the application and prospect of tissue engineering in the treatment of osteonecrosis of the femoral head to provide a new choice for the clinical treatment of osteonecrosis of the femoral head. METHODS:The PubMed database and CNKI database from 2013 to 2023 were searched by the first author with Chinese and English search terms"tissue engineering,mesenchymal stem cells,biological scaffolds,cytokines,osteonecrosis of the femoral head,bone graft,hip preservation".The articles on the treatment of osteonecrosis of the femoral head with tissue engineering technology were selected,and 55 representative articles were included for review after the initial screening of all articles according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)With the continuous development of biotechnology and materials science,great progress has been made in the treatment of osteonecrosis of the femoral head by bone tissue engineering,such as the application of gene-modified mesenchymal stem cells to repair osteonecrosis,the combination of gene recombination technology and surface modification technology with bone tissue engineering in the treatment of osteonecrosis of the femoral head.(2)When applied to the necrotic femoral head,tissue engineering technology can promote the regeneration of necrotic bone tissue and the repair of the vascular system,provide biomechanical stability for the necrotic area,and use bioactive factors to accelerate the repair of seed cells to complete the regeneration of new bone in necrotic area.(3)However,most of these studies are still in the animal experiment stage,and there are still many unsolved problems and challenges in bone tissue engineering research.With the rapid development of nanotechnology,tissue engineering and clinical medicine,biomimetic replacement bone grafting materials with perfect performance are expected to come into being.(4)In the future,bone tissue engineering for osteonecrosis of the femoral head is expected to be a satisfactory treatment for patients with hip preservation.

Objective:To describe the current status and trends in the outcomes and care practices of extremely preterm infants at 22-25 weeks′ gestation age from the Chinese Neonatal Network (CHNN) from 2019 to 2021.Methods:This cross-sectional study used data from the CHNN cohort of very preterm infants. All 963 extremely preterm infants with gestational age between 22-25 weeks who were admitted to neonatal intensive care units (NICU) of the CHNN from 2019 to 2021 were included. Infants admitted after 24 hours of life or transferred to non-CHNN hospitals were excluded. Perinatal care practices, survival rates, incidences of major morbidities, and NICU treatments were described according to different gestational age groups and admission years. Comparison among gestational age groups was conducted using χ2 and Kruskal-Wallis tests. Trends by year were evaluated by Cochran-Armitage and Jonckheere-Terpstra tests for trend. Results:Of the 963 extremely preterm infants enrolled, 588 extremely preterm infants (61.1%) were male. The gestational age was 25.0 (24.4, 25.6) weeks, with 29 extremely preterm infants (3.0%), 88 extremely preterm infants (9.1%), 264 extremely preterm infants (27.4%), and 582 extremely preterm infants (60.4%) at 22, 23, 24, and 25 weeks of gestation age, respectively. The birth weight was 770 (680, 840) g. From 2019 to 2021, the number of extremely preterm infants increased each year (285, 312, and 366 extremely preterm infants, respectively). Antenatal steroids and magnesium sulfate were administered to 67.7% (615/908) and 51.1% (453/886) mothers of extremely preterm infants. In the delivery room, 20.8% (200/963) and 69.5% (669/963) extremely preterm infants received noninvasive positive end-expiratory pressure support and endotracheal intubation. Delayed cord clamping and cord milking were performed in 19.0% (149/784) and 30.4% (241/794) extremely preterm infants. From 2019 to 2021, there were significant increases in the usage of antenatal steroids, antenatal magnesium sulfate, and delivery room noninvasive positive-end expiratory pressure support (all P<0.05). Overall, 349 extremely preterm infants (36.2%) did not receive complete care, 392 extremely preterm infants (40.7%) received complete care and survived to discharge, and 222 extremely preterm infants (23.1%) received complete care but died in hospital. The survival rates for extremely preterm infants at 22, 23, 24 and 25 weeks of gestation age were 10.3% (3/29), 23.9% (21/88), 33.0% (87/264) and 48.3% (281/582), respectively. From 2019 to 2021, there were no statistically significant trends in complete care, survival, and mortality rates (all P>0.05). Only 11.5% (45/392) extremely preterm infants survived without major morbidities. Moderate to severe bronchopulmonary dysplasia (67.3% (264/392)) and severe retinopathy of prematurity (61.5% (241/392)) were the most common morbidities among survivors. The incidences of severe intraventricular hemorrhage or periventricular leukomalacia, necrotizing enterocolitis, and sepsis were 15.3% (60/392), 5.9% (23/392) and 19.1% (75/392), respectively. Overall, 83.7% (328/392) survivors received invasive ventilation during hospitalization, with a duration of 22 (10, 42) days. The hospital stay for survivors was 97 (86, 116) days. Conclusions:With the increasing number of extremely preterm infants at 22-25 weeks′ gestation admitted to CHNN NICU, the survival rate remained low, especially the rate of survival without major morbidities. Further quality improvement initiatives are needed to facilitate the implementation of evidence-based care practices.

Objective:To investigate the role and related mechanisms of the LiaSR two-component system in acid tolerance and biofilm formation abilities of Streptococcus mutans (Sm) 593. Methods:The growth curves of various Sm strains in pH=5.5 brian heart infusion (BHI) medium were analyzed. And colony forming unit (CFU) was also performed to evaluate the acid tolerance of Sm. Laurdan probe, H +-K +adenosine triphosphate (ATP)ase activity analysis kit, proton permeability assay and real-time fluorescence quantitative PCR (RT-qPCR) were conducted to detect the acid tolerant mechanisms of LiaSR two-component system in Sm. Crystal violet staining, CFU, SYTOX probe and anthrone-sulfuric method were used to analyze the properties and structures of the Sm biofilms. RT-qPCR was conducted to detect the expression levels of underlying regulated genes. Results:The growth of mutants in acidic BHI were inhibited ( P<0.05). The acid tolerance of mutants significantly decreased compared to the wild-type strain ( P<0.05). In mutants, the activity of H +-ATPase (917.06±59.53 and 469.53±47.65) were elevated by 7.22-folds and 3.70-folds compared to the wild-type strain (127.00±50.71) ( P<0.001, P<0.001) and the encoded gene atpD (3.39±0.21 and 1.94±0.17) were also elevated by 3.39-folds and 1.94-folds compared to the wild-type strain (1.00±0.15) ( P<0.001, P=0.001). The Laurdan generalized polarization of mutants (0.18±0.04 and 0.18±0.05) increased significantly compared to the wild-type strain (0.08±0.05) ( P=0.006, P=0.003) and the expression levels of fabM gene were decreased in mutants (0.52±0.11 and 0.57±0.05) by 1/2 ( P=0.014, P=0.022). In liaR deletion mutant, the reduced terminal pH (4.76±0.01) can also be observed ( P<0.001). The total amount of the biofilms of three Sm didn't show significant differences ( P>0.05). But the number of viable bacteria of mutants′ biofilms were decreased [Sm 593: (12.00±2.80)×10 7 CFU/ml; Sm ΔliaS: (2.95±1.13)×10 7 CFU/ml; Sm ΔliaR: (7.25±1.60)×10 7 CFU/ml] ( P=0.001, P=0.024). The extracellular DNA were increased by 18.00-folds and 6.50-folds in mutants′ biofilms (128.73±15.65 and 46.38±5.52) compared to the wild-type strain (7.16±3.62) ( P<0.001, P=0.003). Water-soluble exopolysaccharides could be found up-regulated in liaS deletion mutant [(138.73±10.12) μg/ml] ( P=0.003) along with the expression level of gtfC gene (1.65±0.39) ( P=0.014). The expression level of gtfD were elevated by 47.43-folds and 16.90-folds in mutants ( P<0.001, P=0.010). Conclusions:The LiaSR two-component system can promote the expression of fabM gene and increase the fluidity of Sm which contributes to acid tolerance. The LiaR can also decrease the proton permeability and restrict the entrance of H +. The LiaSR two-component system can negatively regulate the production of the extracellular matrix in Sm biofilm.

OBJECTIVES: To investigate the protective effect of the probiotic bacterium Streptococcus salivarius K12 (K12) against Mycoplasma pneumoniae (Mp) infection in mice. METHODS: Forty male BALB/c mice were randomized into normal control group, K12 treatment group, Mp infection group, and K12 pretreatment prior to Mp infection group. The probiotic K12 was administered daily by gavage for 14 days before Mp infection induced by intranasal instillation of Mp. Three days after Mp infection, the mice were euthanized for analysis of bronchoalveolar lavage fluid (BALF) cell counts and serum levels of secretory immunoglobulin A (sIgA), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). RT-qPCR was performed to detect the P1 and community-acquired respiratory distress syndrome ( CARDS ) toxin of Mp in the lung tissues and the mRNA expressions of TNF-α, IL-6, chemokine 1 (CXCL1), matrix metalloproteinase 9 (MMP9), mucin 5ac (MUC5ac), collagen 3a1 (Col3a1), Toll-like receptor 2 (TLR2) and TLR4; the protein expressions of TLR2 and TLR4 in the lung tissue were detected using Western blotting. Pathological changes in the lung tissue and airway remodeling were examined with HE staining and AB/PAS staining. RESULTS: Compared with the Mp-infected mice with PBS treatment, the infected mice with K12 treatment showed significantly lowered mRNA levels of P1 and CARDS in the lung tissue and reduced white blood cell counts in the BALF (P<0.05). In spite of the absence of significant differences in serum levels of inflammatory factors between the two groups, the mRNA expressions of TNF‑α, IL-6, CXCL1, MMP9, MUC5ac and COL3A1 and the mRNA and protein levels of TLR2 and TLR4 in the lung tissues were significantly lower in K12-treated mice, in which AB/PAS staining showed obviously decreased mucus secretion. CONCLUSIONS K12 pretreatment can effectively reduce pulmonary inflammatory responses, improve airway remodeling and alleviate lung injury in Mp-infected mice.
Animals ; Mice ; Pneumonia, Mycoplasma/metabolism* ; Mice, Inbred BALB C ; Toll-Like Receptor 2/metabolism* ; Mycoplasma pneumoniae ; Male ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Lung/microbiology* ; Toll-Like Receptor 4/metabolism* ; Streptococcus salivarius ; Probiotics/administration & dosage* ; Bronchoalveolar Lavage Fluid ; Matrix Metalloproteinase 9/metabolism* ; Mucin 5AC/metabolism* ; Chemokine CXCL1/metabolism* ; Immunoglobulin A, Secretory/metabolism* ; Bacterial Toxins ; Bacterial Proteins