ObjectiveThe full name of vertebroplasty is percutaneous vertebroplasty (PVP). It is a clinical technique that injects bone cement into the diseased vertebral body to achieve strengthening of the vertebra. The research on the safety and efficacy of bone cement is the basis for clinical application. In this study, vertebroplasty is used to evaluate and compare the safety and efficacy of Tecres and radiopaque bone cement in experimental pigs, and to determine the puncture method suitable for pigs and the pre-clinical evaluation method for the safety and efficacy of bone cement. MethodsTwenty-four experimental pigs (with a body weight of 60-80 kg) were randomly divided into an experimental group (Group A) and a control group (Group B). Group A was the Tecres bone cement group, and Group B was the radiopaque bone cement group, with 12 pigs in each group. Under the monitoring of a C-arm X-ray machine, the materials were implanted into the 1st lumbar vertebra (L1) and 4th lumbar vertebra (L4) of the pigs via percutaneous puncture using the unilateral pedicle approach. The animals were euthanized at 4 weeks and 26 weeks after the operation, respectively. The L4 vertebrae were taken for compressive strength testing, and the L1 vertebrae were taken for hard tissue pathological examination to observe the inflammatory response, bone necrosis, and degree of osseointegration at the implantation site. ResultsThe test results of compressive strength between groups A and B showed no significant difference at 4 weeks and 26 weeks after bone cement implantation (P > 0.05). Observation under an optical microscope (×100) revealed that at 4 weeks postoperatively, both groups A and B showed that the bone cement was surrounded by proliferative fibrous tissue, with lymphocyte infiltration around it. The bone cement was combined with bone tissue, the trabecular arrangement was disordered, and osteoblasts and a small amount of osteoid were formed. At 26 weeks postoperatively, bone cement was visible in both groups A and B. The new bone tissue was mineralized, the trabeculae were fused, the trabecular structure was regular and dense with good continuity, and no obvious inflammatory reaction was observed. ConclusionIn experimental pig vertebrae, there were no significant differences observed in the compressive strength, inflammation response, bone destruction, and integration with the bone between Tecres and non-radiopaque bone cement. Both exhibited good biocompatibility and osteogenic properties. It indicates that using vertebroplasty to evaluate the safety and efficacy of bone cement in pigs is scientifically sound.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Objective:To investigate the effectiveness of new cryoprotective agents in preserving and transplanting human adipose tissue.Methods:The adipose tissue samples were obtained from healthy adult females who underwent liposuction at the Department of Plastic Surgery of Peking University Third Hospital from January to March 2022. The adipose tissue samples were centrifuged and then randomly divided into 9 groups. These groups were cryopreserved in liquid nitrogen using different cryoprotective agents [group A, group B, and dimethyl sulfoxide (DMSO) group] and cryopreservation times (1-month, 2-month, and 3-month groups), respectively. The cryoprotective agent formulation in group A was dextrose glycoside 40 (DEX), amino acids, vitamins, and inorganic salts. In group B, the formulation included DMSO and DEX. The ratio of cryoprotective agent in the DMSO group was 10% DMSO, 20% fetal bovine serum (FBS), and 70% DMEM-12. For cryopreservation, 5 ml cryogenic tubes were used with a fat to cryoprotective agent ratio of 3∶2, and each group contains 6 tubes for cryopreservation. After thawing the adipose tissue, HE staining was used to observe the histological morphology. Immunohistochemical staining was employed for the quantitative analysis of lipid droplet-encapsulated protein (Perilipin), and the Perilipin positivity rate was calculated by the ratio of the number of positive cells to the total number of cells. Adipocyte viability was assessed using the CCK-8 method. Thirty-eight healthy, clean nude mice were selected and divided into 3 groups of 12 mice each according to the use of different cryoprotective agents (groups A, B, and DMSO), while the other 2 mice were used as the day 0 control group. The mean fat freezing duration for all groups was 3 months. After nude mice were anesthetized intraperitoneally, 0.9 ml of thawed cryopreserved fat was injected into the dorsum bilaterally. The rate of adipose tissue retention was calculated by MRI scanning and three-dimensional software at 1, 2, and 3 months after transplantation, and compared between the groups. The fat grafts were explanted from the mice after they were sacrificed, and then subjected to histological morphology and quantitative analysis of Perilipin by using HE staining and immunohistochemical staining. GraphPad Prism 8.0 software was used for statistical analysis of the data. The data that conformed to a normal distribution were expressed as Mean ± SD. The overall comparison between multiple groups used analysis of variance for repeated measures. The comparison of data between groups at the same time point used Tukey’s multiple comparison test.Results:The morphology of adipose tissue in different cryoprotective agent groups closely resembled that of normal fresh adipose tissue after being cryopreserved in liquid nitrogen for 1-3 months. The difference in the proportion of Perilipin-stained positive cells in each group was not statistically significant ( P>0.05). The CCK-8 method indicated that the effect of the DMSO group was superior to groups A and B at 1 and 3 months of cryopreservation ( P<0.01), and that the DMSO group and group B were superior to group A at 2 months of cryopreservation ( P<0.01). In the animal experiments, there was no statistically significant difference between the groups in the volume retention rate 1-3 months after cryopreserved fat transplantation ( P>0.05). Additionally, the adipose tissues in each group exhibited varying degrees of localized necrosis accompanied by an inflammatory reaction 1-3 months after transplantation. There was no statistically significant difference in the Perilipin staining positivity between the groups ( P>0.05). Conclusion:The use of new cryoprotective agents for cryopreserving adipose tissue does not show a significant difference compared to the traditional cryoprotective agent. However, it is theoretically safer as it avoids the potential toxic effects of using DMSO or FBS on the human body.

Objective To investigate the efficacy and safety of intravenous thrombolysis with low-dose and standard-dose recombinant tissue plasminogen activator(rt-PA)in the elderly patients(aged over 80 years)with acute ischemic stroke(AIS).Methods A total of 201 elderly patients with AIS treated at Tianjin Fourth Central Hospital from February 2019 to February 2023 were prospectively included and randomly assigned to the rt-PA low-dose group(n=93,0.6 mg/kg)and rt-PA standard-dose group(n=108,0.9 mg/kg).The incidence of intra-cranial hemorrhage,symptomatic intracranial hemorrhage,fatal intracranial hemorrhage,neurologic deterioration within 7 days and mortality within 90 days were observed to evaluate the safety.The neurologic improvement rate and good prognosis rate at 90 days were used to evaluate the effectiveness.A stratified analysis of 90-day outcomes was performed based on stroke severity and age.Results The incidence of intracranial hemorrhage,symptomatic intracranial hemorrhage and fatal intracranial hemorrhage within 7 days in rt-PA low-dose group was lower than that in rt-PA standard-dose group(P＜0.05).There were no statistically significant differences between the two groups concerning the residual safety index and the effectiveness index.The 90-day good prognosis rate of moderate stroke sub-group and of≥90 years of age sub-group in rt-PA low-dose group were both higher than that of rt-PA standard-dose group(P＜0.05).Conclusions For AIS patients with moderate stroke and aged over 90 years,intravenous thrombolytic therapy with rt-PA 0.6 mg/kg is recommended.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To evaluate the diagnostic value of PSA and the f/t PSA ratio in prostate cancer screening in Chinese people.Methods:Original articles on the application of PSA and f/t PSA ratio in prostate cancer screening among Chinese population were retrieved from Pubmed, Embase, Cochrane, China National Knowledge Infrastructure (CNKI), Wanfang data and VIP databases from the establishment of the database to June 2023. The literature quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2(QUADAS-2) tool. A meta-analysis was performed with Stata 15.1 software.Results:A total of 26 articles were included, encompassing 18 407 individuals, of whom 4 095 were diagnosed with prostate cancer based on biopsy and postoperative pathological examination, while the rest were patients with other prostate diseases or healthy individuals. 24 used a PSA threshold of>4.0 ng/ml as the cutoff for prostate cancer screening, the pooled sensitivity was 0.88(95% CI: 0.84-0.91), the specificity was 0.42(95% CI: 0.34-0.50), and the area under the summary receiver operating characteristic (SROC) curve (AUC) was 0.7(95% CI: 0.73-0.81). Four articles considered a PSA threshold of>10.0 ng/ml for prostate cancer screening (three of which used the above two cutoff values), the pooled sensitivity was 0.83(95% CI: 0.74-0.89), the specificity was 0.67(95% CI: 0.45-0.84), and the AUC of the SROC was 0.79(95% CI: 0.75-0.83). Eleven articles used the f/t PSA ratio as a screening tool for prostate cancer. When the f/t PSA ratio was<0.16, the pooled sensitivity was 0.82(95% CI: 0.76-0.87), the specificity was 0.76(95% CI: 0.67-0.83), and the AUC of the SROC was 0.86(95% CI: 0.83-0.89). Conclusion:In the screening for prostate cancer in China, PSA has a relatively high sensitivity, and the f/t PSA ratio has a better specificity. Combined application of the two indices is recommended.

Objective To establish an analytical method combining gas chromatography-tandem mass spectrometry(GC-MS)and liquid chromatography-tandem mass spectrometry(LC-MS)to detect diazepam residue in bait nest materials and fish samples,and improve the pretreatment steps of samples to make the experimental results accurate and the sample processing convenient and fast.Methods Taking diazepam as the research object,samples were extracted with methanol and dichloromethane/n-hexane as solvents according to the type,and the supernatant was taken for detection after centrifugation.Results The diazepam standard sample showed a good linear relationship in the range of 10～10 000 ng/mL.The retention times in methanol and mixed solvent were 13.54 min and 13.83 min,respectively,and the correlation coefficients were 0.998 and 0.999,respectively;The limit of detection(LOD)of using methanol as extraction solvent was 2 ppb,and limit of quantification(LOQ)was 6 ppb.The LOD of using mixed solvents was 5 ppb,and the LOQ was 15 ppb.When the sample is a bait nest material,the GC-MS spectrum was clear and standard,and the peak shape was sharp and prominent;When the sample is biological specimen,the GC-MS spectra are disturbed by matrix,while the LC-MS data is more accurate and faster.Conclusion It is more appropriate to use GC-MS to determine the content of bait nest materialsamples,and it is more accurate to LC-MS to determine the content of fish samples due to the complexity of the organism.

Objective:To investigate the effectiveness of new cryoprotective agents in preserving and transplanting human adipose tissue.Methods:The adipose tissue samples were obtained from healthy adult females who underwent liposuction at the Department of Plastic Surgery of Peking University Third Hospital from January to March 2022. The adipose tissue samples were centrifuged and then randomly divided into 9 groups. These groups were cryopreserved in liquid nitrogen using different cryoprotective agents [group A, group B, and dimethyl sulfoxide (DMSO) group] and cryopreservation times (1-month, 2-month, and 3-month groups), respectively. The cryoprotective agent formulation in group A was dextrose glycoside 40 (DEX), amino acids, vitamins, and inorganic salts. In group B, the formulation included DMSO and DEX. The ratio of cryoprotective agent in the DMSO group was 10% DMSO, 20% fetal bovine serum (FBS), and 70% DMEM-12. For cryopreservation, 5 ml cryogenic tubes were used with a fat to cryoprotective agent ratio of 3∶2, and each group contains 6 tubes for cryopreservation. After thawing the adipose tissue, HE staining was used to observe the histological morphology. Immunohistochemical staining was employed for the quantitative analysis of lipid droplet-encapsulated protein (Perilipin), and the Perilipin positivity rate was calculated by the ratio of the number of positive cells to the total number of cells. Adipocyte viability was assessed using the CCK-8 method. Thirty-eight healthy, clean nude mice were selected and divided into 3 groups of 12 mice each according to the use of different cryoprotective agents (groups A, B, and DMSO), while the other 2 mice were used as the day 0 control group. The mean fat freezing duration for all groups was 3 months. After nude mice were anesthetized intraperitoneally, 0.9 ml of thawed cryopreserved fat was injected into the dorsum bilaterally. The rate of adipose tissue retention was calculated by MRI scanning and three-dimensional software at 1, 2, and 3 months after transplantation, and compared between the groups. The fat grafts were explanted from the mice after they were sacrificed, and then subjected to histological morphology and quantitative analysis of Perilipin by using HE staining and immunohistochemical staining. GraphPad Prism 8.0 software was used for statistical analysis of the data. The data that conformed to a normal distribution were expressed as Mean ± SD. The overall comparison between multiple groups used analysis of variance for repeated measures. The comparison of data between groups at the same time point used Tukey’s multiple comparison test.Results:The morphology of adipose tissue in different cryoprotective agent groups closely resembled that of normal fresh adipose tissue after being cryopreserved in liquid nitrogen for 1-3 months. The difference in the proportion of Perilipin-stained positive cells in each group was not statistically significant ( P>0.05). The CCK-8 method indicated that the effect of the DMSO group was superior to groups A and B at 1 and 3 months of cryopreservation ( P<0.01), and that the DMSO group and group B were superior to group A at 2 months of cryopreservation ( P<0.01). In the animal experiments, there was no statistically significant difference between the groups in the volume retention rate 1-3 months after cryopreserved fat transplantation ( P>0.05). Additionally, the adipose tissues in each group exhibited varying degrees of localized necrosis accompanied by an inflammatory reaction 1-3 months after transplantation. There was no statistically significant difference in the Perilipin staining positivity between the groups ( P>0.05). Conclusion:The use of new cryoprotective agents for cryopreserving adipose tissue does not show a significant difference compared to the traditional cryoprotective agent. However, it is theoretically safer as it avoids the potential toxic effects of using DMSO or FBS on the human body.

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.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.