Neonatal respiratory distress syndrome(NRDS)is one of the most common causes of neo-natal respiratory failure and death.Early and timely diagnosis and treatment,and monitoring the disease condi-tion are of great significance to improve the survival rate.In recent years,cardiopulmonary ultrasound(CPUS)has been gradually popularized for use in NRDS.This article systematically and comprehensively discusses the value and application current status of CPUS in diagnosis and monitoring of NRDS.

Objective:To explore the feasibility of using left ventricular pressure-strain loop (PSL) to evaluate left ventricular myocardial work in patients with severe arterial pulmonary hypertension (sPAH) and to elucidate the interaction between left and right ventricles.Methods:A total of 30 sPAH patients (case group) and 30 healthy individuals (control group) who received medical examination at Inner Mongolia Autonomous Region People′s Hospital from November 2020 to April 2022 were selected. Routine echocardiography data were collected and left ventricular myocardial work analysis was performed. The parameters obtained included overall work index (GWI), overall useful work (GCW), overall useless work (GWW), and overall work efficiency (GWE). The differences in myocardial work parameters between the two groups were compared, and the correlation analysis between ventricular strain parameters and other conventional echocardiography parameters was performed.Results:(1) Compared with the control group, there was no statistically significant difference in general clinical data between the sPAH group except for pulmonary artery systolic pressure (PASP) (all P>0.05). (2) The parameters of right ventricular diameter (Rv-d)/left ventricular diameter (Lv-d), right ventricular wall thickness, right ventricular area change fraction (RVFAC), tricuspid annular displacement (TAPSE) in the sPAH group showed statistically significant differences compared to the control group ( t=21.305, 12.485, 12.359, 8.095, all P<0.05). The parameters of left ventricular conventional echocardiography, left ventricular end diastolic volume (LVEDV) The cardiac output (CO) was smaller than that of the control group ( t=4.443, 2.458, all P<0.05). (3) The overall left ventricular longitudinal strain (LVGLS) and right ventricular longitudinal strain (RVGLS) in the sPAH group were lower than those in the control group ( t=2.927, 22.350, all P<0.05). (4) The GWI, GCW, and GWE of the sPAH group were lower than those of the control group, while GWW was higher than that of the control group, with statistical significance ( t=8.297, 5.520, 15.251, 11.389, all P<0.05). (5) The left ventricular GWI, GCW, and GWE in the sPAH group were negatively correlated with LVGLS, RVGLS, and PASP (all P<0.01), and positively correlated with TASPE and RVFAC (all P<0.01); GWW was positively correlated with PASP, RVGLS, and LVGLS (all P<0.01), and negatively correlated with RVFAC and TAPSE (all P<0.01). Conclusions:PSL can accurately and sensitively reflect the relationship between early left ventricular function changes and left and right ventricular function in sPAH patients, providing a new reference for clinical evaluation of cardiac function.

Objective: To investigate the role of the glycogen synthase kinase 3β (GSK3β) and the peroxisome proliferator-activated receptor alpha (PPARα) signaling pathway in acute liver failure and related mechanisms in a mouse model of acute liver failure induced by D-galactosamine/lipopolysaccharide (D-GalN/LPS). Methods: C57BL/6 mice were given intraperitoneal injection of D-GalN/LPS to establish a mouse model of acute liver failure. SB216763 was used to inhibit the activity of GSK3β and PPARα siRNA was used to inhibit the expression of PPARα. Western blotting was used to measure the expression of PPARα protein. The changes in liver pathology were observed to evaluate liver injury, and the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess liver function. Quantitative real-time PCR was used to measure the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-12p40 (IL-12p40), and PPARα. A one-way analysis of variance was used for comparison of means between multiple groups; the least significant difference test was used for data with homogeneity of variance, and the Games-Howell method was used for data with heterogeneity of variance. Results: In the mice with liver failure induced by D-GalN/LPS, GSK3β inhibition promoted the mRNA and protein expression of PPARα (F = 13.18 and 301.36, P = 0.00 and 0.00). In the mice with acute liver failure induced by D-GalN/LPS, GSK3β inhibition alleviated liver bleeding, inflammation, and necrosis and reduced the serum levels of ALT (F = 25.16, P = 0.000) and AST (F = 12.96, P = 0.001), as well as the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.005), and IL-12p40 (F = 14.17, P = 0.015) in liver tissue. The inhibition of PPARα expression reversed the liver-protecting effect of GSK3β inhibition, which manifested as aggravation in liver bleeding, inflammation, and necrosis, increases in the serum levels of ALT (F = 25.16, P = 0.001) and AST (F = 12.96, P = 0.000), and an increase in the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.024), and IL-12p40 (F = 14.17, P = 0.001) in liver tissue. Conclusion In mice with acute liver failure induced by D-GalN/LPS, the GSK3β-PPARα-inflammatory factor signaling pathway may play an important role. GSK3β inhibition has a protective effect in mice with acute liver failure possibly by activating the inhibitory inflammatory factor of PPARα.

Objective To analyze the role of cysteinyl aspartate specific proteinase-1 (caspase-1) in a mouse model of D-galactosamine (D-GalN) and lipopolysaccharide (LPS) induced acute liver failure (ALF) and to study the possible mechanism. Methods C57BL/ 6 mice were randomly divided into four groups including control group, Z-WEHD-FMK (caspase-1 inhibitor) treatment group, ALF model group and Z-WEHD-FMK-treated ALF group. The mouse model of ALF was established by intraperitoneally injec-ting the mice with D-GalN (450 mg/ kg) and LPS (10 μg/ kg). The damages in liver tissues were evaluated based on the histopathological examination and the levels of alanine transaminase (ALT) and aspartate trans-aminase (AST) in serum samples. Western blot assay was performed to analyze the expression of caspase-1 and the phosphorylation of glycogen synthase kinase 3β (GSK-3β). The qRT-PCR was used to measure the expression of inflammatory cytokines at transcriptional level. Results The expression of caspase-1 at both mRNA and protein levels were gradually increased during the development of ALF. Compared with the mice with ALF, those in the Z-WEHD-FMK-treated ALF group showed less severe liver damages on histopatholog-ical examination and decreased levels of ALT and AST in serum samples [ALT: (479. 2±39. 5) U/ L vs (998. 5±60. 4 ) U/ L, P<0. 05; AST: ( 478. 5±28. 6) U/ L vs ( 1 180. 7±91. 4) U/ L, P<0. 05]. The expression of TNF-α, IL-1β, IL-18 and IL-33 at transcriptional level were significantly suppressed in mice with ALF upon the Z-WEHD-FMK intervention. Results of the Western blot assay indicated that Z-WEHD-FMK suppressed the activities of GSK-3β by enhancing its phosphorylation. Conclusion This study demon-strated that caspase-1 could promote the activation of GSK-3β resulting in the development of inflammation responses and liver damages during the development of ALF in mice.

OBJECTIVETo investigate the protective mechanism of endoplasmic reticulum stress (ERS) inhibition against inflammation-induced acute liver injury using a mouse model.

METHODSMarrow-derived stem cells were isolated from mouse femur and used to derive macrophages for analysis in experimental inflammation conditions, established by exposure to LPS and consequent activation of TLR4. Tunicamycin, an ERS chemical inducer, was applied to interfere the inflammation model condition.Affect on the inflammation-related factor MAPK was detected by western blot, and affects on gene expression of inflammatory factors were measured by real-time quantitative PCR. Affect on TNFa was also measured by ELISA.

RESULTSExpression of TNFa, IL-6 and IL-1b was induced upon exposure to LPS, with the peak levels being reached at 4 hours of exposure (TNFa, 0.82+/-0.24; IL-1 b, 2.20+/-0.69; IL-6, 0.330+/-0.150). Tunicamycin significantly enhanced the LPS-induced up-regulation of TNFa, IL-6 and IL-1b expression (TNFa, 1.44+/-0.38, t=2.8, P<0.05; IL-1b, 16.063.40, t =7.93, P<0.05; IL-6, 31.1610.60, t=5.08, P<0.05). The tuniamycin treatment also enhanced the LPS-induced up-regulation of the protein expression of phospo-p38, phospho-JNK and phoshpo-ERK.

CONCLUSIONERS collaborates with LPS to promote the TLR4-mediated inflammatory response of macrophages, and this collaboration may be a pathogenic mechanism underlying progressive development of acute liver injury.

Animals ; Disease Models, Animal ; Endoplasmic Reticulum Stress ; Inflammation ; Interleukin-6 ; Lipopolysaccharides ; Liver ; Macrophages ; Mice ; Toll-Like Receptor 4 ; Up-Regulation

Objective To investigate the effects of peroxisome proliferator-activated receptor α( PPARα) on macrophage-mediated inflammatory responses with the interference of lipopolysaccharide and the possible mechanism.Methods The bone marrow stem cells were isolated from the femora of mice.The granulocyte-macrophage colony stimulating factor ( GM-CSF) was used to stimulate the in vitro differentiation from bone marrow stem cells into primary macrophages.An in vitro model with cultured cells expressing in-flammatory cytokines was established by treating the primary macrophages with lipopolysaccharide ( LPS) .A specific chemical agonist, Wy-14643, was used to activate PPARα. Autophagy inhibitors including 3-methyladenine (3-MA) and small interfering RNA against Atg7 ( Atg7 siRNA) were used to inhibit the autophagy.Western blot assay was performed to detect the expression of autophagy-related proteins ( Atg5, Atg7, Beclin-1 and LC3).The transcriptional levels of TNF-α, IL-1β, IL-6, Atg5, Atg7 and Beclin-1 were analyzed by qRT-PCR.Results Compared with the macrophages treated with LPS alone, those pretreated with various concentrations of Wy-14643 (10 μmol/L, 25 μmol/L and 50 μmol/L) showed inhibited ex-pression of proinflammatory cytokines ( TNF-α,IL-1βand IL-6) and enhanced expression of autophagy-relat-ed proteins (Atg5, Atg7 and Beclin-1) at mRNA level in a dose-dependent manner.The expression of auto-phagy-related proteins (Atg5, Atg7, Beclin-1 and LC3) by macrophages was promoted with the pretreatment of Wy-14643 as indicated by Western blot assay.The transcriptional levels of TNF-α, IL-1βand IL-6 were increased in Wy-14643 pretreated-macrophages after stimulation with 3-MA or Atg7 siRNA .Conclusion PPARαsuppressed the macrophage-mediated inflammatory responses by promoting autophagy, suggesting that the PPARα-autophagy pathway might be one of the signaling pathways regulating LPS induced-inflamma-tory responses.

OBJECTIVETo study the role of endoplasmic reticulum stress (ERS) in acute liver failure (ALF) using a mouse model of D-Galactosamine/lipopolysaccharide (D-GalN/LPS)-induced ALF.

METHODSThe ALF model was established by administering intraperitoneal (i.p.) injections of D-Ga1N (700 mg/kg) and LPS (10 mug/kg) to six C57BL/6 mice. Three of the modeled mice were also administered 4-phenylbutyrate (4-PBA; 100 mg/kg i.p.) at 6 hours before the onset of ALF and served as the intervention group. Non-modeled mice served as controls. All mice were analyzed by western blotting and qRT-PCR to determine the expression levels of ERS-related proteins in liver tissue. Liver function was assessed by measuring levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum. Extent of injury to the liver tissue was assessed by hematoxylin-eosin staining and histological analysis. qRT-PCR was also used to detect differences in expression of inflammation-related genes, and western blotting was also used to detect differences in expression of the apoptosis related protein Caspase-3.The extent of apoptosis in liver tissue was assessed by TUNEL assay.

RESULTSThe ERS markers GRP78 and GRP94 showed increased expression at both the gene and protein levels which followed progression of ALF. The ERS effector proteins XBP-1, ATF-6 and IRE 1 a involved in the unfolded protein response were activated in the early stages of ALF, and the ERS-induced apoptosis regulators Caspase-12 and CHOP were activated in the late stage of ALF. Inhibition of ERS by 4-PBA intervention protected against injury to liver tissue and function, as evidenced by significantly lower levels of serum ALT and AST and a remarkably decreased extent of histological alterations. Furthermore, the inhibition of ERS suppressed expression of the proinflammatory cytokines TNFa, IL-6 and IL-1 β, and reduced the extent of hepatocyte apoptosis.

CONCLUSIONERS is activated in the mouse model of D-GalN/LPS-induced ALF. Inhibition of ERS may be protective against liver injury and the mechanism of action may involve reductions in inflammatory and apoptotic factors and/or signaling. Therefore, inhibiting ERS may represent a novel therapeutic approach for treating ALF.

Animals ; Apoptosis ; Disease Models, Animal ; Endoplasmic Reticulum Stress ; Galactosamine ; adverse effects ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL

Objective To investigate the changes of extracellular histones during the course of acute liver failure in mice as well as its therapeutic potential.Methods WT mice (C57BL/6) were randomly (random number) allocated to inducing acute liver failure by lethal doses of GalN/LPS injected i.p.Hepatic function,apoptosis of hepatocytes and histological indexes were measured at different intervals following GalN/LPS challenge.The levels of extracellular histones were determined by using ELISA and Western blot methods.Meanwhile,GalN/LPS-treated mice were administered with anti-histone H3 and antihistone H4 neutralized antibodies,respectively.Results Administration of GalN/LPS to mice caused acute liver failure,characterized by significant elevation of plasma ALT levels and massive hepatocyte apoptosis or necrosis.All mice died within 9-12 hours.The levels of nucleosomes and extracellular histones H3 and H4 were increased considerably in a time-dependent manner.The survival rates in GalN/LPS-treated mice were improved remarkably following administration of anti-histone H3 and H4 neutralized antibodies (P =0.037,P =0.025),likely due to the significant inhibition of TNF-production.Conclusions Extracellular histones are an important mediator implicated in the pathogenesis of acute liver failure.Anti-histones show promising potential in the treatment of acute liver failure,which deserves further investigation in the future.

Objective To analyze the role of a key intracellular signaling molecule GSK3β in hepatocyte apoptosis induced by endoplasmic reticulum stress (ERS).Methods Using mouse hepatoma cell lines(Hepa 1) as cell apoptosis model triggered by tunicamycin,an endoplasmic reticulum stress inducer.One hour before Hepa 1 apoptosis induced by tunicamycin,SB216763 specifically inhibited the activity of GSK3β.Living cells/apoptotic cells were detected using acetoxymethyl (AM)/propidium iodide (PI) staining; Furthermore,the measurement of lactate dehydrogenase(LDH) of cell culture supernatant to evaluate the apoptosis.We detect p-GSK3β,GSK3β,the ERS-related protein(GRP78,CHOP and caspase-12) and caspase-3,cleaved caspase-3 protein expression using Western blot.Results Endoplasmic reticulum stress induced by tunicamycin promotes GSK3β activity; Inhibition of GSK3β activity alleviates endoplasmic reticulum stress:the expression of GRP78,CHOP and caspase-12 expression are inhibited.At the same time,GSK3β activity inhibition significantly reduced the endoplasmic reticulum stress-induced apoptosis:compared to cell apoptosis model group,the intervention group of SB216763 showed that the level of LDH decreased significantly,and PI staining of apoptotic cells was also significant reduction.Western blot results showed that the inhibition of GSK 3 β activity reduced reactive cleaved caspase-3 protein.Conclusion GSK3β is an important signaling molecule in the apoptosis pathway induced by endoplasmic reticulum stress ;Endoplasmic reticulum stress promotes hepatocyte apoptosis by mediating GSK3β.