BACKGROUND:The reasonable implantation range of femoral prosthesis in unicompartmental knee arthroplasty in patients with osteoporosis has not been investigated,and previous studies have often been based on unicompartmental knee arthroplasty models in normal bone,with fewer mechanical studies in models with non-normal bone.Complications after unicompartmental knee arthroplasty have been shown to be highly associated with osteoporosis. OBJECTIVE:To analyze the biomechanical effects of the coronal inclination of the Sled fixed platform femoral prosthesis on unicompartmental knee arthroplasty in patients with osteoporosis and to find the correlation between osteoporosis and mid-and long-term complications after unicompartmental knee arthroplasty. METHODS:Based on the digital imaging technology to obtain the data of the knee joint and prosthesis,a normal bone knee model is then created by using specialized software such as Mimics and Geomagic studio.Based on a validated normal bone knee model,an osteoporotic knee model was created by changing the material parameters.Totally 14 unicompartmental knee arthroplasty finite element models were created using Sled fixed platform femoral prosthesis:standard position(0°),varus and valgus angles:3°,6°,9° in the normal bone and osteoporosis groups.Stress changes on the surface of polyethylene liner,cancellous bone under tibial prosthesis,and cortical bone were calculated and analyzed in all unicompartmental knee arthroplasty models. RESULTS AND CONCLUSION:(1)In the osteoporotic models,the high stress values of the polyethylene liner surface and the cancellous bone under the tibial prosthesis increased with the increase of the tilt angle of the femoral prosthesis,and the high stress values of the cortical bone surface under the tibial prosthesis increased with the increase of the prosthesis valgus angles and decreased with the increase of the varus angles.(2)For the polyethylene liner surface as well as the subcortical bone surface of the tibial prosthesis,the high stress values of the models for each inclination angle in the osteoporosis group were greater than those of the corresponding models in the normal bone group.For the surface of the cancellous bone under the tibial prosthesis,the high stress values of the tilt angle models of the osteoporosis groups were smaller than those of the normal bone groups.(3)Osteoporosis may cause biomechanical abnormalities in the internal structures of the knee after unicondylar replacement,increasing the potential risk of postoperative aseptic loosening of the prosthesis and periprosthetic fractures.Varus and valgus of the femoral prosthesis in the coronal plane should be avoided as much as possible when performing medial unicompartmental knee arthroplasty with a Sled fixation platform in osteoporotic knees.

Pyroptosis is the programmed death of cells accompanied by an inflammatory response and is widely involved in the development of a variety of diseases, such as infectious diseases, cardiovascular diseases, and neurodegeneration. It has been shown that cellular scorching is involved in the pathogenesis of pulmonary arterial hypertension ( PAH) in cardiovascular diseases. Patients with PAH have perivascular inflammatory infiltrates in lungs, pulmonary vasculopathy exists in an extremely inflam-matory microenvironment, and pro-inflammatory factors in cellular scorching drive pulmonary vascular remodelling in PAH patients. This article reviews the role of cellular scorch in the pathogenesis of PAH and the related research on drugs for the treatment of PAH, with the aim of providing new ideas for clinical treatment of PAH.

BACKGROUND:Artificially synthesized hydroxyapatite ceramic granules are widely used in clinical practice to repair large-volume bone defects.However,the osteogenic effect of hydroxyapatite ceramic granules prepared by high-temperature sintering is limited by their low degradability and bioactivity. OBJECTIVE:To prepare biomimetically precipitated nanocrystalline calcium phosphate granules by a novel low-temperature deposition technique,and to characterize their physicochemical properties and cytocompatibility. METHODS:Biomimetically precipitated nanocrystalline calcium phosphate granules were prepared using a modified supersaturated calcium phosphate mineralization solution and a repeated settling and decantation washing method.Hydroxyapatite bioceramic granules were used as the control.The morphology and phase composition of the granules were characterized by scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy.The specific surface area,porosity distribution,hardness and hydrophilicity of the granules were characterized by BET-N2 method,hardness test,and contact angle test.The adsorption properties of the granules for bovine serum albumin and fetal bovine serum protein were determined by bicinchoninic acid assay.The two kinds of granules or granule extracts were co-cultured with human umbilical cord mesenchymal stem cells,and the cell proliferation was detected by MTT assay. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of the two kinds of particles was slightly rough and accompanied by tiny particles,the surface of the hydroxyapatite bioceramic particles was dense and smooth,and the biomimetically precipitated nanocrystalline calcium phosphate granules were mainly composed of needle/plate crystals with non-uniform nanometer size,and formed a nanopore structure between the crystals.X-ray diffraction and Fourier transform infrared spectroscopy exhibited that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had smaller crystalline particles,lower crystallinity,and more binding water and carbonic acid groups.Compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules had higher specific surface area,better hydrophilicity,lower hardness,and higher protein adsorption capacity.(2)The results of MTT assay showed that the two kinds of granule extracts had no cytotoxicity,human umbilical cord mesenchymal stem cells survived well on the surface of the two kinds of granules,and the biomimetically precipitated nanocrystalline calcium phosphate granules had stronger cell proliferation activity.(3)These findings indicate that compared with hydroxyapatite bioceramic granules,biomimetically precipitated nanocrystalline calcium phosphate granules have better physicochemical properties and cytocompatibility.

Objective To study the pharmacokinetics and bioequivalence of two formulations of rasagiline mesylate tablets in healthy subjects under fasting and fed conditions.Methods The two-period,two-sequence,crossover study design was adopted in the fasting study.Thirty-six subjects were enrolled and given either test preparation or reference preparation 1 mg respectively in two periods.After collecting plasma samples,the plasma concentration of rasagiline was determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS)and the bioequivalence was evaluated using the average bioequivalence(ABE)method.The four-period,two-sequence,fully replicate crossover study design was adopted in the fed study.Forty-eight subjects were enrolled and given the test preparation or the reference preparation at a dose of 1 mg twice respectively in four periods.According to the degree of intra-individual variation of Cmax,AUC0-t and AUC0-∞,the equivalence was evaluated using the reference-scaled average bioequivalence and ABE method,respectively.Results In the fasting study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(9.70±3.14)and(9.62±3.85)ng·mL-1,AUC0-t were(6.03±1.47)and(6.02±1.95)ng·h·mL-1,AUC0-∞ were(6.13±1.51)and(6.12±1.97)ng·h·mL-1.The 90％confidence interval(CI)of the geometric mean ratio(GMR)were 94.11％-118.06％,99.22％-107.74％and 99.16％-107.44％for Cmax,AUC0-t and AUC0-∞,respectively,which were within the acceptance criteria of 80.00％-125.00％.In the fed study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(3.00±1.92)and(3.52±1.77)ng·mL-1,AUC0_t were(5.02±1.20)and(5.06±1.20)ng·h·mL-1,AUC0-∞ were(5.11±1.23)and(5.14±1.22)ng·h·mL-1.The 90％CI of GMR were 96.99％-101.19％and 97.17％-101.41％for AUC0-t and AUC0-∞,which were within the acceptance criteria of 80.00％-125.00％.The 95％upper confidence bound of Cmax for were less than"0",and the point estimate of GMR were within the acceptance criteria of 80.00％-125.00％.The incidence of adverse events in fasting and fed studies was 22.86％and 22.92％,respectively,and all adverse events were moderate to mild.Conclusion The two rasagiline mesylate tablets were bioequivalent,and both the formulations were well tolerated.

Objective:To investigate the correlation between the levels of CC chemokine ligand 2 (CCL2) and periostin (POSTN) in serum and alveolar lavage fluid of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) complicated with respiratory virus infection and lung function.Methods:From March 2020 to March 2023, 96 patients with acute exacerbation of COPD admitted to our hospital were collected. Among them, 34 patients with concurrent respiratory virus infection were included in the infected group, and 62 patients without respiratory virus infection were included in the uninfected group. Enzyme linked immunosorbent assay (ELISA) was applied to detect the expression levels of CCL2 and POSTN in serum and alveolar lavage fluid. Pearson method was applied to analyze the correlation between CCL2 and POSTN levels in serum and alveolar lavage fluid of infected patients and lung function indicators.Results:The levels of CCL 2 ( t=12.633, 9.253 2, 2) and POSTN ( t=12.370, 7.383) were significantly increased in the infected group compared with the uninfected group ( P<0.05). Compared with the uninfected group, the 6-minute walking test (6 MWT), peak expiratory flow rate (peak expiratory flow, PEF), forced expiratory volume at the first second (forced expiratory volume in one second, FEV 1), and the forced lung capacity (forced vital capacity, FVC), FEV 1/FVC, and maximum middle breath mean flow rate (maximal mid-expiratory flow curve, MMEF) were significantly lower ( t=14.141, 24.165, 22.421, 21.223, 5.278, 29.456, P<0.05). Correlation analysis showed that the levels of CCL2 and POSTN in the serum and alveolar lavage fluid of the infected group were negatively correlated with the levels of 6MWT, PEF, FEV1, FVC, FEV1/FVC, and MMEF ( P<0.05). Conclusions:CCL2 and POSTN levels were highly expressed in serum and alveolar lavage fluid of patients with respiratory virus infection during acute exacerbation of COPD, which were closely related to lung function.

Background::Thoracic aortic aneurysm (TAA) is a fatal cardiovascular disease, the pathogenesis of which has not yet been clarified. This study aimed to identify and validate the diagnostic markers of TAA to provide a strong theoretical basis for developing new methods to prevent and treat this disease.Methods::Gene expression profiles of the GSE9106, GSE26155, and GSE155468 datasets were acquired from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the "limma" package in R. Least absolute shrinkage and selection operator (LASSO), support vector machine-recursive feature elimination (SVM-RFE), random forest, and binary logistic regression analyses were used to screen the diagnostic marker genes. Single-sample gene set enrichment analysis (ssGSEA) was used to estimate immune cell infiltration in TAA.Results::A total of 16 DEGs were identified. The enrichment and functional correlation analyses showed that DEGs were mainly associated with inflammatory response pathways and collagen-related diseases. Collagen type I alpha 1 chain ( COL1A1) and synaptotagmin like 2 ( SYTL2) were identified as diagnostic marker genes with a high diagnostic value for TAA. The expression of COL1A1 and SYTL2 was considerably higher in TAA vascular wall tissues than in the corresponding normal tissues, and there were significant differences in the infiltration of immune cells between TAA and normal vascular wall tissues. Additionally, COL1A1 and SYTL2 expression were associated with the infiltration of immune cells in the vascular wall tissue. Single-cell analysis showed that COL1A1 in TAA was mainly derived from fibroblasts and SYTL2 mainly from cluster of differentiation (CD)8 + T cells. In addition, single-cell analysis indicated that fibroblasts and CD8 + T cells in TAA were significantly higher than those in normal arterial wall tissue. Conclusions::COL1A1 and SYTL2 may serve as diagnostic marker genes for TAA. The upregulation of SYTL2 and COL1A1 may be involved in the inflammatory infiltration of the vessel wall and poor extracellular matrix remodeling, promoting the progression of TAA.

Objective To develop an inpatient assessment form for geriatric syndromes,aiming to quickly and accurately determine whether elderly inpatients are at risk of geriatric syndromes.Methods From May 2021 to December 2023,an initial item pool for the scale was proposed through literature review.Sixteen experts from four fields of geriatric nursing,nursing management,nursing education,and geriatric medicine were selected from seven institutions in six provinces and cities across the country.Two rounds of Delphi expert consultation were conducted to inquire about the assessment form.Results The enthusiasm coefficient of the two rounds of expert consultation was 100.00%,and the expert authority coefficient was 0.88.In the first round of expert consultation,the importance ratings of the three-level indicators ranged from 4.06 to 4.75,with a coefficient of variation of 0.09 to 0.25,a full score rate of 43.75%to 81.25%,and a Kendall coordination coefficient W of 0.210.In the second round of expert consultation,the importance ratings of the three-level indicators ranged from 4.63 to 4.94,with a coefficient of variation of 0.05 to 0.13,a full score rate of 62.50%to 93.75%,and a Kendall coordination coefficient W of 0.419.After two rounds of expert consultation,the inpatient assessment form for geriatric syndromes was finally determined,including 5 first-level indicators(past history,physical function,common geriatric symptoms,mental and psychological status,socioeconomic status),26 second-level indicators,and 41 third-level indicators.Conclusion The inpatient assessment form for geriatric syndromes developed in this study is scientifically and practically feasible and can be used to quickly identify the risk of geriatric syndromes in elderly inpatients.

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 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 monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.