Obiective Alzheimer’s disease (AD) is a degenerative disease of the central nervous system (CNS) caused by a variety of risk factors. There are various pathological changes, but apoptosis of the neurological meridian cells is one of the most important pathological bases. Hyperlipidemia is a high-risk factor for the development of AD, which can lead to increased levels of oxidized low-density lipoprotein (ox-LDL) in brain tissues. PCSK9 is a protease closely related to lipid metabolism, but studies have shown that it may be related to the development of AD. LRP1 is abundantly expressed in neuronal cells, and it is an important transporter for the clearance of Aβ. There is now a large amount of literature confirming that PCSK9 can induce the degradation of LRP1. PI3K/AKT is an important signaling pathway in vivo, which plays an important role in apoptosis, and there is now a large amount of literature confirming that LRP1 activates the PI3K/AKT pathway, which has an anti-apoptotic effect. So can PCSK9 affect the PI3K/AKT pathway through LRP1 and thus regulate neuronal apoptosis? This deserves further investigation.The aim of this study was to explore the role of PCSK9 in mediating ox-LDL pro-apoptotic neuronal cell death and its mechanism, and then further elaborate the mechanism of hyperlipidemia leading to neurodegenerative diseases such as AD. MethodsFirstly, PC12 cells were treated with different concentrations of ox-LDL (0, 25, 50, 75 and 100 mg/L) for 24 h. Oil red O staining was used to detect lipid accumulation in PC12 cells, Hoechst33258 staining and flow cytometry to detect apoptosis in PC12 cells, ELISA to detect the content of Aβ secreted by PC12, Western blot to detect expression of SREBP2, PCSK9 and LRP1. Then PC12 cells were treated with 75 mg/L ox-LDL for different times (0, 6, 12, 24, 48 h), and Western blot were performed to detect the expression of SREBP2, PCSK9 and LRP1. Finally, after transfecting 100 nmol/L PCSK9 siRNA into PC12 cells for 48 h, PC12 cells were treated with 75 mg/L ox-LDL for 24 h, Hoechst33258 staining and flow cytometry to detect apoptosis rate of PC12 cells, and Western blot to detect PCSK9, LRP1, PI3K, AKT, P-PI3K , P-AKT, NF-κB, Bcl-2, Bax, Caspase-9 and Caspase-3 expression, and ELISA detected Aβ content secreted by PC12 cells. Resultsox-LDL increased lipid accumulation and promoted apoptosis and Aβ secretion in PC12 cells, as well as increasing the expression of SREBP2 and PCSK9 and decreasing the expression of LRP1 in PC12 cells. pCsk9 siRNA could be inhibited through the PI3K/AKT pathway and the NF-κB-Bcl-2/Bax-Caspase-9/3 pathway to inhibit ox-LDL-induced apoptosis in PC12 cells while increasing Aβ secretion in PC12 cells. Conclusionox-LDL plays a bidirectional regulatory role in ox-LDL-induced apoptosis of PC12 cells by inducing an increase in PCSK9 expression and a decrease in LRP1 expression in PC12 cells, which in turn affects different signaling pathways downstream.

Objective To investigate the influences of Lycium barbarum polysaccharide on apoptosis of corneal epithelial cells induced by hypertonicity through regulating adenosine monophosphate activated protein kinase(AMPK)/uncoordinated 51-like kinase 1(ULK1)autophagy pathway.Methods The ophthalmoxerosis cell model was established by osmotic pressure of 500 mOsm·L-1 on corneal epithelial cells.They were divided into model group,positive control group(0.3％sodium hyaluronate eye drops),inhibitor group(1 mg·mL-1 Lycium barbarum polysaccharide+10 μmol·L-1compound C),experimental-L,-H groups(0.5,1.0 mg·mL 1 Lycium barbarum polysaccharide),and normal cultured CRL-11135 cells were taken as blank group(no treatment was performed).Cell apoptosis was detected by flow cytometry.Autophagy was detected by MDC staining.Western blot was used to detect the expressions of p-AMPK/AMPK and p-ULK1/ULK1.Results The apoptosis rates of experimental-L,experimental-H,positive control,inhibitor,model and blank groups were(26.47±2.13)％,(13.68±2.21)％,(12.54±2.16)％,(18.73±2.12)％,(37.56±3.25)％and(6.35±2.14)％;the relative contents of autophagosomes were(59.63±8.14)％,(89.89±9.04)％,(90.31±9.13)％,(62.75±7.26)％,(43.11±6.45)％and(100.00±0.00)％;p-AMPK/AMPK were 0.45±0.07,0.64±0.08,0.66±0.06,0.53±0.04,0.34±0.05 and 0.87±0.06;p-ULKl/ULKl were 0.54±0.06,0.75±0.05,0.77±0.03,0.65±0.04,0.46±0.04 and 0.92±0.08,respectively.The above indexes in experimental-L,-H groups and positive control group were significantly different from those in model group(all P＜0.05);the above indexes in inhibitor group were significantly different from those in experimental-H group(all P＜0.05).Conclusion Lycium barbarum polysaccharide can inhibit the apoptosis of corneal epithelial cells induced by hypertonicity by activating the AMPK/ULK1 autophagy pathway.

Objective To compare the effects of 20 mg qd and 10 mg bidadministration of iprrazole enteric-coated tablets on the control of gastric acid in healthy subjects.Methods A randomized,single-center,parallel controlled trial was designed to include 8 healthy subjects.Randomly divided into 2 groups,20 mg qd administration group:20 mg enteric-coated tablets of iprrazole in the morning;10 mg bid administration group:10 mg enteric-coated tablets of iprrazole in the morning and 10 mg in the evening.The pH values in the stomach of the subjects before and 24 h after administration were monitored by pH meter.The plasma concentration of iprazole after administration was determined by HPLC-MS/MS.The main pharmacokinetic parameters were calculated by Phoenix WinNonlin(V8.0)software.Results The PK parameters of iprrazole enteric-coated tablets and reference preparations in fasting group were as follows:The Cmax of 20 mg qd group and 10 mg bid group were(595.75±131.15)and(283.50±96.98)ng·mL-1;AUC0-t were(5 531.94±784.35)and(4 686.67±898.23)h·ng·mL-1;AUC0-∞ were(6 003.19±538.59)and(7 361.48±1 816.77)h·ng·mL-1,respectively.The mean time percentage of gastric pH＞3 after 20 mg qd and 10 mg bid were 82.64％and 61.92％,and the median gastric pH within 24 h were 6.25±1.49 and 3.53±2.05,respectively.The mean gastric pH values within 24 h were 5.71±1.36 and 4.23±1.45,respectively.The correlation analysis of pharmacokinetic/pharmacodynamics showed that there was no significant correlation between the peak concentration of drug in plasma and the inhibitory effect of acid.Conclusion Compared with the 20 mg qd group and the 10 mg bid group,the acid inhibition effect is better,the administration times are less,and the safety of the two administration regimes is good.

Objective To explore the effect of propranolol on femoral fracture healing in mice through regulation of microRNA-92a-3p(miR-92a-3p)and its mechanism.Methods C57BL/6J male mice were randomly divided into sham group(equal amount of 0.9％NaCl),model group(equal amount of 0.9％NaCl),experimental group(50 mg·kg-1 propranolol administration),inhibitor group(mice were injected with 100 mg·kg-1 miR-92a-3p inhibitor via tail vein on the basis of the experimental group).Femur was severed and molded in all mice except sham operation group.X-ray was used to observe bone healing.Quantitative real time polymerase chain reaction was used to detect the expression of miR-92a-3p in femur tissues.The expression level of bone formation and bone metabolism markers was detected by enzyme linked immunosorbent assay.Western blot was used to detect the expression of pathway-related proteins.Results The X-ray scores of femur in sham group,model group and experimental group were 11.20±2.60,4.70±1.50 and 9.60±2.40,respectively;the relative expression levels of miR-92a-3p in sham operation group,model group,experimental group and inhibitor group were 1.00±0.09,0.73±0.06,0.90±0.07 and 0.78±0.06;alkaline phosphatase levels were(35.21±2.63),(43.16±3.29),(67.58±5.37)and(49.62±4.05)U·L-1,respectively;crosslaps levels were(4.57±0.52),(8.41±0.91),(4.26±0.67)and(5.73±0.84)ng·mL-1,respectively;the relative expression levels of brain derived neurotrophic factor were 1.00±0.14,0.58±0.05,0.83±0.09 and 0.71±0.06,respectively;the relative expression levels of phospho-tyrosine kinase receptor B were 1.00±0.12,0.62±0.05,0.89±0.08 and 0.76±0.07,respectively;the relative expression levels of phospho-extracellular regulated protein kinases were 1.00±0.11,0.54±0.04,0.78±0.07 and 0.65±0.05,respectively.The above indexes in the model group were compared with those in the sham group,those in the experimental group were compared with those in the model group,and those in the inhibitor group were compared with those in the experimental group,and the differences were statistically significant(P＜0.05,P＜0.001).Conclusion Propranolol can promote femoral fracture healing in mice,which may be achieved by up-regulating miR-92a-3p activation of brain derived neurotrophic factor/tyrosine kinase receptor B/extracellular regulated protein kinases signaling pathway.

GNPS-based mass spectrum-molecular networks is an effective strategy for rapidly identifying known natural products and discovering novel structures. The chemical diversity of azaphilones from the fermentation extracts of Talaromyces sp. HK1-18 was studied by molecular network technique. Three linear tricyclic azaphilones, sequoiamonacins A-C (2a, 2b, 1), were isolated by silica gel column chromatography and high performance liquid chromatography from the extracts of the fungal strain of HK1-18, and their structures were identified by nuclear magnetic resonance and high-resolution mass spectrometry. Guided by the mass spectra of sequoiamonacins A-C (2a, 2b, 1), the cluster of sequoiamonacinoid analogues was discovered from the full molecular networking of HK1-18. By analyzing the MS/MS fragments of each parent ion in this cluster, 7 azaphilones (3-9) included 6 new ones (4-9) were predicted successfully. Then the MS/MS cracking regularity of this type of azaphilones was revealed. Compound 1 showed anti-inflammatory activity, which can inhibit the production of interleukin-1α (IL-1α) in lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7, with an inhibitory rate of 29% at the concentration of 12.5 μg·mL^-1.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the clinical characteristics of Ureaplasma urealyticum(UU)infection and colonization in extremely preterm infants and its impact on the incidence of bronchopulmonary dysplasia(BPD).Methods A retrospective analysis was conducted on 258 extremely preterm infants who were admitted to the Department of Neonatology,Shenzhen Maternity and Child Healthcare Hospital,from September 2018 to September 2022.According to the results of UU nucleic acid testing and the evaluation criteria for UU infection and colonization,the subjects were divided into three groups:UU-negative group(155 infants),UU infection group(70 infants),and UU colonization group(33 infants).The three groups were compared in terms of general information and primary and secondary clinical outcomes.Results Compared with the UU-negative group,the UU infection group had significant increases in the incidence rate of BPD,total oxygen supply time,and the length of hospital stay(P<0.05),while there were no significant differences in the incidence rates of BPD and moderate/severe BPD between the UU colonization group and the UU-negative group(P>0.05).Conclusions The impact of UU on the incidence of BPD in extremely preterm infants is associated with the pathogenic state of UU(i.e.,infection or colonization),and there are significant increases in the incidence rate of BPD,total oxygen supply time,and the length of hospital stay in extremely preterm infants with UU infection.UU colonization is not associated with the incidence of BPD and moderate/severe BPD in extremely preterm infants.

Exosomes can ameliorate neuronal cell injury induced by hypoxia-ischemia,but the relation-ship between astrocyte-derived exosomes(As-exo)and mitochondrial function,mitochondrial associated ER membrane(MAM)function and whether mitochondrial autophagy is relevant is currently unclear.The aim of this study was to investigate the role of astrocyte-derived exosomes in the regulation of mito-chondrial function,MAM and mitochondrial autophagy in PC 12 cells after oxygen and glucose depriva-tion/reoxygenation(OGD/R).Exosomes were extracted from the supernatant of the astrocyte culture me-dium by ultracentrifugation.Using the live cell imaging system,we observed that fluorescently labeled exosomes could show obvious enrichment in PC 12 cells at 24 h.Meanwhile,co-localization of exosomes with mitochondria could be observed under the laser confocal scanning microscope;mitochondrial pres-sure changes were detected using the Seahorse cellular energy metabolism fractionation instrument.The result showed that basal respiration in the OGD/R group,compared with that in the control group,proton leakage,maximal respiration and ATP-related respiration were significantly reduced(P＜0.05 or P＜0.01),and all four indexes were elevated and statistically significant in the OGD/R+exo group compared with the control group(P＜0.05 or P＜0.01).The results of the co-localization of the mitochondria and ER showed that the structure of the MAM was harmed by oxygen-sugar deprivation and then reoxygen-ation,and the structure of As-exo and the mitochondria appeared to have a distance-reduced polymeriza-tion phenomenon,while the mitochondria and ER co-localized.The co-localization results of mitochondri-a and ER showed that the structure of MAM was damaged by oxygen deprivation and reoxygenation,and the aggregation phenomenon of MAM was weakened by the treatment of As-exo;the flow-through results showed that As-exo could restore the decrease of the mitochondrial membrane potential and the elevation of the ROS by oxygen deprivation to a certain degree.Western blotting showed that As-exo could signifi-cantly inhibit the mitochondrial autophagy-associated tension protein homologue induced hypothetical ki-nase 1(PTEN induced kinase 1(PINK1)and Parkin protein(parkin RBR E3 ubiquitin protein ligase(Parkin))were elevated,and the addition of As-exo decreased LC3 Ⅱ/LC3 Ⅰ protein expression,ele-vated P62 protein expression,and reduced OGD/R-induced mitochondrial autophagy.The results showed that OGD/R treatment can cause mitochondrial dysfunction,MAM structural changes and increased mito-chondrial autophagy in PC12 cells,and As-exo treatment can improve mitochondrial function,attenuate the formation of MAM,and reduce mitochondrial autophagy in PC 12 cells,which can have the potential of preventing the reperfusion injury in ischemic stroke.

ObjectiveTo understand the situation of nosocomial infection in cancer hospitals and its changing trend， so as to provide a basis for adjusting the focus of nosocomial infection prevention and control in cancer hospitals. MethodsData of nosocomial infection quality control indices of Sun Yat-sen University Cancer Center from 2019 to 2021 were obtained through the nosocomial infection monitoring system， and the changes of these indices across the three years were analyzed by Chi-square test and Cochran-Armitage trend test. ResultsFrom 2019 to 2021， the incidence rates of nosocomial infection in this hospital were 0.80%， 0.78% and 0.57%， which decreased significantly year by year （P<0.001）. Among them， surgical site and respiratory system infection were more common， accounting for 35.75% and 31.08%， respectively. Gram-negative bacteria and fungi were the main pathogens. The incidence rate of multidrug-resistant bacteria in hospital increased year by year， from 0.08‰ to 0.14‰ （P<0.001）， among which methicillin-resistant staphylococcus aureus， carbapenem-resistant Enterobacter and bacteria producing ultra-broad spectrum β-lactamase （ESBLs） bacteria increased significantly. The incidence rates of three-tube associated infections were no different across 3 years （P>0.05）， which were still at high levels. ConclusionFrom 2019 to 2021， the prevention and control of nonsocomial infection in the cancer hospital has been improved overall. Meanwhile， the infections of respiratory system and surgical sites， ESBLs related multidrug-resistant bacteria and three-tube are weak links in cancer specialized hospitals， which need to be emphasized and improved.

AIM: To investigate the effect of orthokeratology lens on ocular surface and meibomian gland in children and adolescents of different ages.METHODS: A total of 120 cases(240 eyes)of myopic children and adolescents treated in the optometry clinic of our hospital from December 2020 to February 2021 were retrospectively selected, and they were divided into the orthokeratology group(60 cases, 120 eyes)and the frame glasses group(60 cases, 120 eyes)according to the myopia correction methods. The changes in ocular surface and meibomian gland after wearing glasses were analyzed, and those changes in patients of different ages were compared between the two groups.RESULTS: Corneal curvature decreased, non-invasive tear film break-up time(NIBUT)shortened and meibomian gland score increased at 3, 6, 9 and 12mo in the orthokeratology group after wearing lens, while lower tear meniscus height increased at 6, 9 and 12mo compared with that before wearing lens. In the frame glasses group, the lower tear meniscus height was higher at 6 and 9mo than that before wearing glasses(both P<0.05). At the same time point, the corneal curvature of the orthokeratology group was significantly lower than that of the frame glasses group at all time points, the NIBUT at 3, 9 and 12mo after wearing the lens was shorter than that of the frame glasses group and the meibomian gland scores were higher at 6, 9 and 12mo than those at the same time point in the glasses group(all P<0.05). After wearing lens for 12mo, the corneal curvature of the orthokeratology group at all ages was significantly lower than that of the frame glasses group, the NIBUT of the orthokeratology group at 8 to 12 years old and 13 to 15 years old was significantly lower than that of the frame glasses group, and the meibomian gland score was significantly higher than that of the frame glasses group(all P<0.05).CONCLUSION: Orthokeratology lens may affect the ocular surface and meibomian glands function, and the effects on ocular surface are more pronounced in children and adolescents under 12 years old. Therefore, younger children and adolescents could be prioritized for myopia correction with framed glasses, and then wearing orthokeratology lens when they get older.