Octapeptin has strong antibacterial activity against Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii, while it also has activity against some Gram-positive bacteria. This study used natural octapeptin A3 and B3 as lead compounds for structural modification. Twenty-one peptide derivatives (including A3 and B3) containing eight amino acid residues were prepared by solid-phase synthesis, and evaluated for antibacterial activity and renal cytotoxicity. Among them, three compounds 6, 7 and 17 exhibited broad-spectrum antibacterial activity and significantly enhanced the activity for Gram-positive bacteria while maintaining the activity of Gram-negative bacteria. Several compounds improved the activity for Pseudomonas aeruginosa. Compound 7 was active against all test strains and had relatively low renal cytotoxicity. The results provide a basis for the further development of novel polypeptide antibiotics.

This study investigates whether compounds in Salvia miltiorrhiza Bunge can bind to the Toll like receptor 4/myeloid differentiation protein 2 (TLR4/MD2) protein complex and exhibit anti-inflammatory activity. Virtual screening of reported chemical components of Salvia miltiorrhiza Bunge against TLR4/MD2 was conducted in this study. The selected compound, neoprzewaquinone A (Neo A), was tested for its impact on the binding of lipopolysaccharide (LPS) to receptors on the cell membrane, its affinity for the protein, its influence on the dimerization of TLR4 and MD2 in LPS-induced cells, and its effects on the phosphorylation of nuclear factor-κB (NF-κB) p65 protein and the secretion of inflammatory cytokines in cells. Results indicate that Neo A in Salvia miltiorrhiza Bunge exhibited the highest virtual binding affinity with TLR4/MD2, with a value of -12.8 kcal·mol^-1. Neo A significantly inhibited the binding of LPS to receptors on the cell membrane (P < 0.01). Moreover, Neo A demonstrated affinity for rhTLR4/MD2, rhTLR4, and rhMD2, with K_D values of 267, 534, and 228 nmol·L^-1, respectively. Amino acid residues like TYR131 and PHE121 in TLR4/MD2 might play a role in the alkyl and π-alkyl hydrophobic interactions with Neo A. Neo A also significantly inhibited the dimerization of TLR4 and MD2 in LPS-mediated cells (P < 0.01) and markedly suppressed the phosphorylation of NF-κBp65 protein (P < 0.05). Furthermore, Neo A significantly or markedly inhibited the secretion of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in LPS-induced cells (P < 0.05, P < 0.01). In conclusion, Neo A exerts its anti-inflammatory effects by binding TLR4/MD2 then disrupting the binding of LPS to TLR4/MD2. It may serve as a TLR4/MD2 inhibitor with the potential to treat inflammation-related diseases targeting TLR4/MD2.

Objective To explore the value of serum D-dimer(D-D),fibrinogen(FIB),platelet(PLT),C-reactive pro-tein(CRP)and tissue plasminogen activator inhibitor(PAI)-1 levels in predicting lower extremity deep vein thrombosis(DVT)after hip joint surgery in the elderly.Methods A retrospective analysis was performed on 165 elderly patients with hip joint surgery admitted from February 2020 to May 2022,including 89 males and 76 females,aged from 60 to 75 years old with an average of(66.43±5.48)years,and there were 102 cases of femoral neck fracture and 63 cases of femoral head necrosis.Serum levels of D-D,FIB,PLT,CRP and PAI-1 tests were performed in all patients within 24 hours after admission,and the patients were divided into DVT group and non-DVT group according to whether they developed DVT.Results The levels of D-D,FIB,PLT,CRP,and PAI-1 in the DVT group were higher than those in the non-DVT group(P＜0.001).Spearman analysis showed that DVT was positively correlated with PLT,CRP,D-D,FIB,and PAI-1 levels(r=0.382,0.213,0.410,0.310,0.353,all P＜0.001).The results of binary Logistic regression analysis showed that D-D and PLT were independent factors affecting the occurrence of DVT(OR=0.038,0.960,P=0.032,0.011).The area under curve(AUC)of D-D,FIB,PLT,CRP,PAI-1,and the five combined predictions for DVT were 0.843,0.692,0.871,0.780,0.819,and 0.960,respectively.The AUC of the five combined predictions was higher than that of the single prediction(P＜0.05).Conclusion D-D,FIB,PLT,CRP and PAI-1 are effective in predicting DVT after hip surgery in the elderly,and the combined prediction of the five factors has higher effi-cacy.

Aim To dynamically characterize neuronal damage in the cortex and hippocampus of mice follow-ing acute cerebral ischemia/reperfusion(I/R).Meth-ods Male C57BL/6J mice weighing 25-28 g under-went middle cerebral artery occlusion using the fila-ment method,followed by 1 hour of reperfusion to es-tablish the acute cerebral I/R injury mouse model.The experiment comprised a sham surgery group,I/R-6 h group,I/R-24 h group,and I/R-72 h group.Longa neurological function score was used to assess the neu-rological function.Triphenyltetrazolium chloride(TTC)staining was conducted to detect cerebral in-farct volume.Hematoxylin and eosin(HE)staining was utilized to observe brain tissue pathological dam-age.Nissl staining was performed to evaluate neuronal damage.Immunofluorescence histochemistry staining was employed to assess the activation of astrocytes and microglia,as well as neuronal loss.Transmission elec-tron microscopy was used to examine mitochondrial damage in hippocampal neurons.Western blot analysis was conducted to detect the expression levels of mito-chondrial fission-fusion-related proteins p-Drp1/Drp1,Mff,Fis1,and OPA1.Results With prolonged cere-bral I/R time,neurological functional impairment,cerebral infarct volume,neuronal damage in the cortex and hippocampus,glial cell activation,neuronal loss,and mitochondrial damage gradually worsened in mice.The expression of mitochondrial fission-related proteins increased gradually,while the expression of mitochon-drial fusion-related proteins decreased gradually.Con-clusions Neuronal pathological damage,such as glial cell activation,neuronal loss,and mitochondrial dam-age,is gradually aggravated with prolonged cerebral I/R time,which may be associated with mitochondrial dynamics imbalance.

Aim To examine the neuroprotective im-pacts of total saponins from Trillium tschonoskii maxim(TST)on cerebral ischemia-reperfusion injury(CIRI)in rats and delve into the mechanisms of ferroptosis.Methods The CIRI model was prepared by dividing male SD rats into the model group,TST(0.1 g·kg-1)group,Donepezil hydrochloride(0.45 mg·kg-1)group,and sham group.The cognitive functions of rats in each group were assessed through the Morris water maze test,the changes in neurological function were evaluated using the Zea-Longa method,the infarct area was observed via TTC staining,and the pathologi-cal alterations in brain tissue were analysed using HE and Nissl staining.To further investigate the underly-ing mechanism,the mitochondrial structural changes were examined using transmission electron microscopy,and the levels of GSH-PX,MDA,and SOD were ana-lyzed.Additionally,the expressions of GPX4 and Nrf2 proteins were evaluated through immunohistochemistry and immunofluorescence.Furthermore,the protein lev-els of Keap1/Nrf2/HO-1 and Nrf2/SLC7A11/GPX4 pathways in rats were examined using Western blot-ting.Results The rats in the model group displayed diminished learning and memory capabilities in com-parison to those in the sham group,as well as a signifi-cantly increased cerebral infarction area and higher neurological function scores(P＜0.01),significantly increased cerebral infarct area,disordered and loosely arranged neurons,and reduced Nissl bodies.Addition-ally,mitochondria showed typical signs of ferroptosis.Changes related to ferroptosis included decreased activ-ities of SOD and GSH-PX(P＜0.01)and increased MDA levels(P＜0.01).The expression of GPX4 and Nrf2-positive cells was significantly reduced,along with decreased fluorescence intensity of GPX4.Further-more,the protein expression of Keap1,Nrf2,HO-1,GPX4,SLC7A11 in the hippocampus decreased(P＜0.05,P＜0.01).Following the administration of TST,these effects showed improvement.Conclusions TST has neuroprotective effects,enhancing learning and memory abilities while reducing oxidative stress levels.The mechanism may involve the inhibition of ferroptosis through the Keap-1/Nrf2/HO-1 and Nrf2/SLC7 A11/GPX4 pathways.

Objective To investigate the expression and prognostic value of spindle and kinetochore-associated complex subunit 2(SKA2)in cervical cancer tissues,as well as its impact on the proliferation,migration and invasion of cervical cancer cells.Methods The expression of SKA2 in cervical cancer tissues was analyzed by bioinformatics database and immunohistochemical SP method,and the relationship between SKA2 expression level and clinicopathological features of cervical cancer patients and its prognostic value was analyzed.The mRNA expression of SKA2 in human normal cervical cells(HcerEpic)and cervical cancer cells(HeLa,SiHa,CaSki,C-33A)was detected by RT-qPCR.Cervical cancer cells SiHa with higher SKA2 expression level was selected for further study.SiHa cell model with down-regulated SKA2 expression was constructed,and its knockdown effect was verified.Cell proliferation capacity was detected by CCK-8 method,cell migration capacity was detected by cell scratch wound healing assay,and cell migration and invasion capacity was detected by Transwell assay.Results Compared with normal cervical tissues and cells,the expression levels of SKA2 mRNA and protein were higher in cervical cancer tissues and cells,and the differences were statistically significant(P<0.05).High SKA2 expression was associated with FIGO staging in patients with cervical cancer.Furthermore,SKA2 knockdown could inhibit the proliferation,migration and invasion of SiHa cells in cervical cancer(P<0.05).Conclusion SKA2 is up-regulated in cervical cancer tissues and cells,and can promote the proliferation,migration and invasion of cervical cancer cells.The expression level of SKA2 is associated with the progression of cervical cancer,and the prognosis of cervical cancer patients with high SKA2 expression is worse.

Objective:To investigate the molecular mechanism of proteolytic cleavage of unusually large von Willebrand Factor(ULVWF)on endothelial cells by ADAMTS13(a disintegrin and metalloprotease with thrombospondin type 1 repeats-13)in the absence of fluid shear stress,so as to provide a theoretical basis for the pathogenesis of thrombotic thrombocytopenic purpura(TTP)and other thrombotic disorders.Methods:The ADAMTS13-mediated proteolysis of ULVWF on the surface of endothelial cells in the absence of fluid shear stress was observed through immunofluorescence microscopy.The variation in VWF antigen levels in the conditioned media were determined by ELISA assay.The levels of VWF and the proteolytic fragments released into the conditioned media were determined by ELISA assay and Western blot in the absence and presence of fluid shear stress or FⅧ.The effect of ADAMTS13-mediated ULVWF cleavage on the normal distribution of plasma VWF multimers was evaluated by multimer analysis.Histamine stimulated human umbilical vein endothelial cells(HUVECs)were incubated with ADAMTS13 and various N-and C-terminally truncated mutants.Then the ULVWF that maintained binding to the cells were observed through immunofluorescence microscopy and the soluble ULVWF released from endothelial cells was determined by ELISA,so as to demonstrate the domains of ADAMTS13 required for proteolysis of ULVWF on endothelial cells.Results:The ULVWF strings on the endothelial cell surface were rapidly proteolyzed by recombinant and plasma ADAMTS13 in the absence of fluid shear stress.This proteolytic processing of ULVWF depended on incubation time and AD AMTS 13 concentration,but not shear stress and FⅧ.The distribution of VWF releaseded by ADAMTS13-mediated proteolysis was quite similar to that secreted by endothelial cells under histamine stimulation,suggesting the ULVWF cleavage occured at the cell surface.The proteolysis of the ULVWF on endothelial cells required the Cys-rich(CysR)and spacer domains,but not the TSP1 2-8 and CUB domains of ADAMTS13.Conclusion:The ULVWF polymers on endothelial cells are sensitive to ADAMTS13-mediated cleavage even in the absence of fluid shear stress.The findings provide novel insight into the molecular mechanism of ADAMTS13-mediated ULVWF cleavage at the cellular level and may contribute to understanding of the pathogenesis of TTP and other thrombotic disorders.

Objective:To observe the genetic variation of SH2B3 in patients with myeloid neoplasms.Methods:The results of targeted DNA sequencing associated with myeloid neoplasms in the Department of Hematology,Xuanwu Hospital,Capital Medical University from November 2017 to November 2022 were retrospectively analyzed,and the patients with SH2B3 gene mutations were identified.The demographic and clinical data of these patients were collected,and characteristics of SH2B3 gene mutation,co-mutated genes and their correlations with diseases were analyzed.Results:The sequencing results were obtained from 1 005 patients,in which 19 patients were detected with SH2B3 gene mutation,including 18 missense mutations(94.74％),1 nonsense mutation(5.26％),and 10 patients with co-mutated genes(52.63％).Variant allele frequency(VAF)ranged from 0.03 to 0.66.The highest frequency mutation was p.Ile568Thr(5/19,26.32％),with an average VAF of 0.49,involving 1 case of MDS/MPN-RS(with SF3B1 mutation),1 case of MDS-U(with SF3B1 mutation),1 case of aplastic anemia with PNH clone(with PIGA and KMT2A mutations),2 cases of MDS-MLD(1 case with SETBP1 mutation).The other mutations included p.Ala567Thr in 2 cases(10.53％),p.Arg566Trp,p.Glu533Lys,p.Met437Arg,p.Arg425Cys,p.Glu314Lys,p.Arg308*,p.Gln294Glu,p.Arg282Gln,p.Arg175Gln,p.Gly86Cys,p.His55Asn and p.Gln54Pro in 1 case each.Conclusion:A wide distribution of genetic mutation sites and low recurrence of SH2B3 is observed in myeloid neoplasms,among of them,p.Ile568Thr mutation is detected with a higher incidence and often coexists with characteristic mutations of other diseases.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective To evaluate the effect of delayed cleaning on the cleaning and disinfection quality of gastro-scopes after pre-treatment with different solutions.Methods According to the factorial design table,combination of the pre-treatment cleaning solutions(factor A)(including multi-enzyme cleaning solution[A1],clean water[A2])and delayed cleaning durations(factor B)(including 0 minutes after pre-treatment[B1],30 minutes after pre-treat-ment[B2],1 hour after pre-treatment[B3],and 3 hours after pre-treatment[B4])yielded eight groups(A1B1,A1B2,A1B3,A1B4,A2B1,A2B2,A2B3,A2B4).According to the usage order of gastroscopes,96 gastroscopes used in the digestive endoscopy center of a tertiary first-class hospital from May to September,2023 were randomly assigned to each group by random number table method,with 12 gastroscopes in each group.Specimens were taken at four time points:after pre-treatment,before cleaning,after cleaning,and after disinfection.Due to instant clea-ning,no specimen before cleaning were taken from A1B1 and A2B1 groups,thus only 3 specimens were taken from these two groups each.Four specimens were taken from gastroscopes in the rest groups,resulting in 360 specimens in total.The internal condition of the biopsy cavity was observed through a cavity detector during each delayed cleaning period after pre-treatment,and specimens were taken at the subsequent reprocessing processes of the gas-troscopes.The microbial conditions of the gastroscopes after pre-treatment,before cleaning,after cleaning,and af-ter disinfection were compared.Results After pre-treatment with multi-enzyme cleaning solution and clean water,there was no statistically significant difference in microbiological detection result(P＞0.05).The biopsy cavity re-mained moist during the delayed cleaning period.There was no statistically significant difference in the microbial de-tection results of factors A and B before and after delayed cleaning as well as after disinfection(all P＞0.05).There was no interaction effect between factor A and B.The distribution of bacterial colonies and disinfection qualified rate of gastroscopes after pre-treatment with two cleaning solutions were also not statistically different(both P＞0.05).Conclusion Delayed cleaning for 30 minutes,1 hour,and 3 hours after pre-treatment does not affect the cleaning and disinfection quality of gastroscopes.When clinical demand is urgent,immediate cleaning should be carried out.However,a certain buffering time(no longer than 3 hours)before cleaning is acceptable,when cleaning and disin-fection workload is heavy and timely cleaning cannot be carried out.