The periodontal ligament (PDL) plays a crucial role in transmitting and dispersing occlusal force, acting as mechanoreceptor for muscle activity during chewing, as well as mediating orthodontic tooth movement. It transforms mechanical stimuli into biological signals, influencing alveolar bone remodeling. Recent research has delved deeper into the biological and mechanical aspects of PDL, emphasizing the importance of understanding its structure and mechanical properties comprehensively. This review focuses on the latest findings concerning both macro- and micro- structural aspects of the PDL, highlighting its mechanical characteristics and factors that influence them. Moreover, it explores the mechanotransduction mechanisms of PDL cells under mechanical forces. Structure-mechanics-mechanotransduction interplay in PDL has been integrated ultimately. By providing an up-to-date overview of our understanding on PDL at various scales, this study lays the foundation for further exploration into PDL-related biomechanics and mechanobiology.
Periodontal Ligament/cytology* ; Humans ; Biomechanical Phenomena ; Mechanotransduction, Cellular/physiology* ; Stress, Mechanical

Objective:To identify the prognostic value of the Revised 15-item Myelodysplastic Syndrome-specific frailty scale (FS-15) in Chinese patients with myelodysplastic syndromes (MDS) .Methods:This retrospective study analyzed 812 patients with newly diagnosed MDS admitted to the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College from August 2016 to June 2023. Patients were assessed using the FS-15 and subsequently categorized into frail and non-frail groups. Clinical and laboratory characteristics, as well as overall survival (OS), were compared between these groups.Results:① The median patient age was 55 years ( IQR 45–64), with a median follow-up of 22.5 months (95% CI: 20.2–24.9) and a median OS of 43.3 months (95% CI: 36.8–49.8). The median FS-15 score was 0.42, with a cutoff value of 0.44. Male patients demonstrated higher median FS-15 scores than female patients (0.42 vs 0.38, P=0.006). In both the Revised International Prognostic Scoring System (IPSS-R; P=0.001) and Molecular International Prognostic Scoring System (IPSS-M; P=0.014) stratifications, FS-15 scores were significantly higher in the very high-risk group compared with the very low-risk group. ② The median OS was 54.7 months (95% CI: 47.5–NA) and 31.5 months (95% CI: 22.9–41.0) in the nonfrail ( n=452) and frail groups ( n=360), respectively ( P<0.001). The 3-year OS rates were (63.2 ± 3.2) % and (46.4 ± 3.6) % for the non-frail and frail groups, with 5-year OS rates of (49.9 ± 4.7) % and (32.0 ± 4.3) %, respectively ( P<0.001). ③Subgroup analysis revealed that nonfrail patients demonstrated significantly higher 3-year OS rates than frail patients in both the IPSS-M low-risk and very high-risk groups (all P<0.05). Similarly, nonfrail patients demonstrated superior 3-year OS rates compared with frail patients in the IPSS-R very low-risk, low-risk, and high-risk groups (all P<0.05). ④Among patients receiving hypomethylating agent therapy, the overall response rate was significantly higher in the non-frail group than in the frail group (86.7% vs 64.6%, P=0.007). Moreover, the frail group experienced higher rates of treatment-related adverse events, including febrile neutropenia (67.1% vs 47.4%, P=0.016) and liver function abnormalities (30.0% vs 14.5%, P=0.023), compared with the non-frail group. Conclusion:The FS-15 frailty score is a feasible and effective tool for assessing frailty in patients newly diagnosed with MDS in China and serves as a valuable prognostic indicator.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To investigate the clinical value of sarcopenia in predicting the efficacy of bronchial artery chemoembolization(BACE)in patients with lung cancer.Methods The clinical data of 160 patients with lung cancer,who received BACE treatment at the Lishui Municipal Central Hospital of China from December 2012 to August 2021,were retrospectively analyzed.Using CT images to measure and calculate the skeletal muscle index(SMI)at the 4th thoracic vertebra(T4)level,patients with T4-SMI below the gender specific quartile were classified in sarcopenia group(n=40),and patients with T4-SMI above the threshold were classified in non-sarcopenia group(n=120).Kaplan-Meier method was used to compare the differences in progression-free survival(PFS)and overall survival(OS)between the two groups after BACE treatment,and Cox regression analysis was used to determine the risk factors affecting prognosis.Results In the non-sarcopenia group and the sarcopenia group,the median PFS was 5.6 months and 3.0 months respectively(x2=5.141,P=0.023),and the postoperative 14-month PFS rates were 16.7％and 5.0％respectively.There was no statistically significant difference in OS between the two groups(P＞0.05).Cox multivariate analysis showed that sarcopenia(HR=1.557,95％CI=1.083-2.238,P=0.017)was an independent risk factor for postoperative PFS after BACE.Conclusion Sarcopenia is an independent risk factor affecting the efficacy of BACE in patients with lung cancer,and sarcopenia can be used as a predictive indicator for the postoperative efficacy of BACE.

Objective:To identify the prognostic value of the Revised 15-item Myelodysplastic Syndrome-specific frailty scale (FS-15) in Chinese patients with myelodysplastic syndromes (MDS) .Methods:This retrospective study analyzed 812 patients with newly diagnosed MDS admitted to the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College from August 2016 to June 2023. Patients were assessed using the FS-15 and subsequently categorized into frail and non-frail groups. Clinical and laboratory characteristics, as well as overall survival (OS), were compared between these groups.Results:① The median patient age was 55 years ( IQR 45–64), with a median follow-up of 22.5 months (95% CI: 20.2–24.9) and a median OS of 43.3 months (95% CI: 36.8–49.8). The median FS-15 score was 0.42, with a cutoff value of 0.44. Male patients demonstrated higher median FS-15 scores than female patients (0.42 vs 0.38, P=0.006). In both the Revised International Prognostic Scoring System (IPSS-R; P=0.001) and Molecular International Prognostic Scoring System (IPSS-M; P=0.014) stratifications, FS-15 scores were significantly higher in the very high-risk group compared with the very low-risk group. ② The median OS was 54.7 months (95% CI: 47.5–NA) and 31.5 months (95% CI: 22.9–41.0) in the nonfrail ( n=452) and frail groups ( n=360), respectively ( P<0.001). The 3-year OS rates were (63.2 ± 3.2) % and (46.4 ± 3.6) % for the non-frail and frail groups, with 5-year OS rates of (49.9 ± 4.7) % and (32.0 ± 4.3) %, respectively ( P<0.001). ③Subgroup analysis revealed that nonfrail patients demonstrated significantly higher 3-year OS rates than frail patients in both the IPSS-M low-risk and very high-risk groups (all P<0.05). Similarly, nonfrail patients demonstrated superior 3-year OS rates compared with frail patients in the IPSS-R very low-risk, low-risk, and high-risk groups (all P<0.05). ④Among patients receiving hypomethylating agent therapy, the overall response rate was significantly higher in the non-frail group than in the frail group (86.7% vs 64.6%, P=0.007). Moreover, the frail group experienced higher rates of treatment-related adverse events, including febrile neutropenia (67.1% vs 47.4%, P=0.016) and liver function abnormalities (30.0% vs 14.5%, P=0.023), compared with the non-frail group. Conclusion:The FS-15 frailty score is a feasible and effective tool for assessing frailty in patients newly diagnosed with MDS in China and serves as a valuable prognostic indicator.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:To systematically analyze the incidence and influencing factors of frailty in elderly patients with hematologic malignancies.Methods:Research on frailty in elderly patients with hematologic malignancies was retrieved from Chinese and English databases such as China National Knowledge Infrastructure, Wanfang Data, PubMed, and Web of Science. The search period was from database establishment to August 23, 2024. Two researchers screened the included studies, conducted quality assessment, and extracted data. Meta-analysis was conducted using Stata 18 and RevMan 5.4.Results:A total of seven studies were included, encompassing 19 076 elderly hematologic malignancy patients, with a frailty incidence of 59% [95% CI (0.48, 0.69) ]. Meta-analysis revealed that age [ MD=4.31, 95% CI (3.67, 4.96) ], gender [ OR=0.88, 95% CI (0.83, 0.93) ], alcohol consumption [ OR=1.67, 95% CI (1.15, 2.44) ], self-care ability [ MD=-1.79, 95% CI (-3.17, -0.41) ], anemia [ OR=6.67, 95% CI (2.94, 15.14) ], infection [ OR=1.81, 95% CI (1.16, 2.84) ], and neuropathy [ OR=2.52, 95% CI (1.38, 4.61) ] were the influencing factors of frailty in elderly patients with hematologic malignancies. Conclusions:The incidence of frailty is high in elderly patients with hematologic malignancies. Elderly patients with hematologic malignancies who are older, female, consume alcohol, have low self-care ability, anemia, infections, and neuropathy are prone to frailty. Healthcare providers can conduct early screening and intervention for high-risk populations of frailty based on risk factors to improve the quality of life for elderly hematologic malignancy patients.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.