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.

Objective To investigate the effects of epithelial transformation sequence 2(ECT2)and p33ING1 on the metastatic activity of esophageal squamous cell carcinoma(ESCC)cells.Methods The expressions of ECT2 and p33ING1 in esophageal squamous cell carcinoma tissues and adjacent tissues were detected by immunohistochemistry and Western blotting.Human esophageal squamous carcinoma cell line KYSE140 cells were divided into 4 groups:blank group,negative control(pcDNA 3.1 NC)group,overexpression group(pcDNA 3.1 ECT2)and inhibited expression group(si ECT2).MTT assay and cell colony formation assay were used to study the proliferation and growth ability of cells,Transwell assay and scratch assay used to study the invasion and migration ability of cells,and flow cytometry used to detect apoptosis and cell cycle,Western blotting used to detect the effect of ECT2 on p33ING1 protein.Results ECT2 expression increased and p33ING1 expression decreased in esophageal squamous cell carcinoma tissues.Overexpression of ECT2 significantly increased the growth,colony formation,migration and invasion abilities of KYSE140 cells,and decreased the apoptosis rate and p33ING1 expression of KYSE140 cells.In addition,inhibition of ECT2 expression could reverse the above changes.Conclusion The high expression of ECT2 can promote the growth and metastasis of esophageal squamous cell carcinoma KYSE140 cells and inhibit their apoptosis.The mechanism may be related to the inhibition of p33ING1 expression by ECT2.

Objective To establish two golden hamster models infected with hypervirulent Klebsiella pneumoniae via aerosolized intratracheal(i.t.)and intranasal(i.n.)inoculation,and compare their properties.Methods Golden hamsters of 4 to 5 weeks old were exposed to K.pneumoniae NTUH-K2044 via i.t.route and i.n.route respectively.The survival of these golden hamsters was observed and recorded within 14 days of infection before the 50%lethal dose(LD50),survival rate,bacterial respiratory deposition rate,lung bacterial load and histopathology of the infected golden hamsters in the two groups were detected.Results The LD50 of the i.t.route(3×104 CFU)was lower than that of the i.n.route(7×105 CFU)in golden hamsters.After 4×106 CFU NTUH-K2044 infection,the golden hamsters in the i.t.group had 96.46%of the bacteria deposited and colonized in the lung,developed lobar pneumonia and died without exception within 4 days of infection,while those in the i.n.group had 95.62%of the bacteria deposited in the mouth and nose initially before the bacteria moved down to the trachea for colonization and were cleared out gradually.This group mainly acquired bronchopneumonia with relatively mild lung lesions,with a 14-day survival rate of 70%.Conclusion Inoculation routes can make a difference to the disease type of respiratory tract infections in animal models.The i.t.route mainly causes lobar pneumonia with severe lung lesions,while the i.n.route leads to bronchopneumonia with mild lung lesions.The two animal models established above may be utilized for pathogenesis investigation and treatment efficacy evaluation of Klebsiella pneumoniae.

Objective:To investigate the expression of soluble lectin-like oxidized low den-sity lipoprotein receptor-1(sLOX-1)and C1q/tumor necrosis factor related protein 3(CTRP3)in the serum of patients with lower extremity arteriosclerosis obliterans(ASO)and their relationship with restenosis(ISR)after stent intervention.Methods:From June 2019 to June 2022,106 ASO pa-tients who underwent stent intervention in our hospital were regarded as the study subjects.One year after surgery,they were separated into a non ISR group(n=64)and an ISR group(n=42)based on their onset of ISR.The serum levels of sLOX-1 and CTRP3 were compared between the two groups;multivariate Logistic regression was applied to analyze the influencing factors of ISR after stent intervention in ASO patients;ROC curve was applied to analyze the predictive value of se-rum sLOX-1 and CTRP3 levels for ISR after stent intervention in ASO patients.Results:The se-rum sLOX-1 level in the ISR group was obviously higher than that in the non ISR group(P＜0.05),and the CTRP31 level was obviously lower than that in the non ISR group(P＜0.05).The complete occlusion,and sLOX-1 were independent risk factors for ISR after stent intervention in ASO pa-tients,while CTRP3 was a protective factor for ISR after stent intervention in ASO patients(P＜0.05).The AUC of the combination of serum sLOX-1 and CTRP3 in predicting ISR after stent in-tervention in ASO patients was 0.944,with a sensitivity of 97.62％and a specificity of 79.69％,which was superior to the individual predictions of sLOX-1 and CTRP3(Zcombineddetaction-sLOX-1=2.732,Zcombineddetection-CTRP3=2.143,P=0.006,0.032).Conclusion:After ASO stent intervention,the serum level of sLOX-1 was obviously increased in ISR patients,while the level of CTRP3 was obviously reduced,and the combination of the two fatcors has high predictive value for the occurrence of ISR in ASO patients after stent intervention.

Objective To analyze the clinicopathological features, diagnosis and differential diagnosis of bronchiolar adenoma (BA) with primary lung cancer. Methods Data of 17 BA patients complicated with primary lung cancer in Dalian University Affiliated Xinhua Hospital from January 2020 to December 2022 were collected, and the clinical data, histopathological features and immunohistochemical features were summarized. Results 17 patients included 7 males and 10 females, with 49-82 years old. There were 2 squamous cell carcinoma and 15 adenocarcinoma. BA was mostly nodular, without capsule. It had a clear boundary with the surrounding lung tissue, with a major diameter of 0.3-1.5 cm. The section of BA was gray-white, gray-red, gray-brown, with medium-soft texture, and a few had obvious mucus. Microscopically, it was composed of luminal cell layer and basal cell layer, and luminal cells contain mucus cells, ciliated cells, cubic cells and columnar cells. According to the composition of luminal cells, BAs were divided into proximal type and distal type. There were 5 proximal type and 12 distal type, including 1 case of atypical distal BA. Immunohistochemistry results showed that in typical BAs, CK5/6, p63 and p40 were positive in basal cells, thyroid transcription factor-1 was positive in luminal cells and basal cells, and the proliferation index of Ki-67 was 1%. Conclusions BA is a benign tumor, and is a bilayer structure mainly composed of luminal cells and basal cells. However, when the absence or discontinuity of basal cells, BA is easily misdiagnosed as malignancy, which should be highly vigilant.

Persistent left superior vena cava(PLSVC)is a common congenital anomaly of systemic venous drainage,often draining into the right atrium without the need for special treatment.Sometimes,PLSVC drains into the left atrium,creating a right-to-left shunt,leading to reduced blood oxygen saturation and paradoxical embolism,requiring intervention.Traditional surgical ligation of PLSVC is the conventional approach for managing abnormal shunting,but it is associated with significant trauma and carries the risk of damaging the phrenic nerve.Here,we present a case of a patient with right heart dysfunction due to an untreated PLSVC-left atrium communication after corrective surgery for complex congenital heart disease,resulting in left-to-right shunting postoperatively.The patient was successfully treated by using a Plug vascular occluder via a transseptal approach to occlude the PLSVC.To our knowledge,this is the first report of successful closure of the left-to-right shunting through the heart chambers via a transseptal approach,indicating that interventional occlusion is an ideal management approach.

Low-level patent foramen ovale nonocclusion(PFO)is a rare type of PFO in which the PFO opening is low during transcatheter closure of PFO and the distance between the PFO left atrial opening and the root of the septal side of the mitral valve is less than 9 mm,and the smallest model of the current double-disk PFO occluder(18/18)commonly used in clinical practice for low-level PFOs can touch the mitral valve,resulting in increased risk of mitral regurgitation or leaflet abrasion.The risk of mitral regurgitation or leaflet abrasion is increased,and transcatheter closure of PFO procedure can only be abandoned when encountered intraoperatively.In this article,we present a case of successful transcatheter closure of a low-level PFO using the Amplatzer ADOⅡ occluder,which provides new ideas and strategies to deel wtih this rare type of PFO.

Stroke is a cerebrovascular disease characterized by high rates of disability,recurrence and mortal-ity.It results primarily from cerebrovascular rupture or transient/permanent occlusion.Due to the complex pathological mechanism of stroke and the lack of early-stage biomarkers,effective treatment options remain limited.Circular RNAs(circRNAs)are stable and conserved endogenous long noncoding RNA that regulate the pathological process of stroke,in-cluding oxidative stress,inflammation,apoptosis and autophagy.In addition,the regulatory roles of circRNAs in stroke include ceRNA,DNA methylation and histone modification.This review provides a comprehensive overview of circRNA biogenesis,major functions and characteristics.Furthermore,it presents the latest research findings on circRNAs in the context of stroke pathology,with the aim of providing new insights and potential approaches for unraveling the underlying mechanism,diagnosis and treatment of such diseases.

Objective To investigate the effects of simvastatin mediated adenylate activated protein kinase/peroxisome proliferator-activated receptor-γ-coactivator 1 α(AMPK/PGC-1α)pathway on neural function in rats with Parkinson's disease.Methods Parkinson's disease model was established in SD rats.After successful modeling,they were divided into model group,positive group(1.67 mg·kg-1 metoba),experimental-L group(10 mg·kg-1 simvastatin),experimental-H group(20 mg·kg-1 simvastatin),BML-275 group(20 mg·kg-1 simvastatin+0.25 mg·kg-1 AMPK inhibitor BML-275)and 10 normal rats were selected as control group.Enzyme-linked immunosorbent assay(ELISA)was used to detect dopamine(DA),3,4 dihydroxyphenylacetic acid(DOPAC),homovanillic acid(HVA),5-hydroxyindoleacetic acid(5-HIAA),5-hydroxytryptamine(5-HT);Western blot was used to detect the expression of tyrosine hydroxylase(TH)and AMPK/PGC-1α pathway-related proteins;TH expression was detected by immunohistochemistry,malondialdehyde(MDA),superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)were detected by kit.Results The DA of control group,model group,experimental-H group and BML-275 group were(495.63±34.30),(207.53±24.10),(429.39±44.89)and(285.55±20.79)pg·mL-1,respectively;DOPAC were(33.38±2.48),(17.70±1.31),(29.12±1.72)and(20.67±1.45)ng·mL-1,respectively;HVA were(58.75±6.25),(25.27±2.00),(46.16±2.83)and(30.58±1.91)ng·mL-1,respectively;5-HT were(5.62±0.45),(2.37±0.13),(4.42±0.26)and(3.23±0.29)ng·mL-1,respectively;5-HIAA were(11.11±1.08),(3.88±0.30),(7.99±0.63)and(6.04±0.51)ng·mL-1,respectively;p-AMPK protein expression were 0.98±0.06,0.35±0.04,0.80±0.05 and 0.21±0.02,respectively;PGC-1α protein expression were 1.12±0.11,0.40±0.04,0.90±0.08 and 0.58±0.05,respectively.There were statistically significant differences in the above indexes between control group and model group,and between model group and experimental-H group and inhibitor group(all P＜0.05).Conclusion Simvastatin can improve the neural function of Parkinson's disease rats by regulating AMPK/PGC-1α pathway.

Objective To investigate the inhibitory effect of quercetin on Gastro entero pancreatic NEN(GEP-NEN).Methods Human pancreatic neuroendocrine tumor BON-1 cells were randomly divided into control group,quercetin group(80 μmol·L-1 quercetin),quercetin+si-NC group(transfected with si-NC+80 μmol·L-1 quercetin),quercetin+si-growth arrest-specific+ranscript 5(GAS5)group(transfected with si-GAS5+80 μmol·L-1 quercetin).Dual luciferase reporter gene assay was used to verify the targeted binding of GASS5 to miR-18b-5p;real-time quantitative fluorescent PCR(qRT-PCR)was used to detect the mRNA expression levels of B-cell lymphoma-2(Bcl-2)and Bel-2 associated X protein(Bax);positive expression of GAS5 and miR-18b-5p in cells was detected by fluorescence in situ hybridization(FISH)assay.Results Dual luciferase reporter gene results showed that GAS5 was targeted to miR-18b-5p.The GAS5 expression levels of control group,quercetin group,quercetin+si-NC group and quercetin+si-GAS5 group were 1.00±0.13,1.72±0.19,1.78±0.14 and 1.16±0.11,respectively;the expression levels of miR-18b-5p were 1.00±0.15,0.67±0.08,0.72±0.06 and 0.95±0.11 respectively;Bax mRNA expression levels were 1.00±0.12,2.17±0.25,2.32±0.28 and 1.37±0.15,respectively;Bcl-2 mRNA expression levels were 1.00±0.15,0.41±0.05,0.37±0.06 and 1.21±0.13,respectively.The above indexes were significantly different between quercetin group and control group(all P＜0.05);the above indexes were significantly different between quercetin+si-NC group and quercetin+si-GAS5 group(all P＜0.05).Conclusion Quercetin may slow down the development of GEP-NEN by targeting GAS5/miR-18b-5p molecular axis to inhibit cell growth.