Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective:To explore the force distribution on the maxillary dentition when the first and second molars distalized simultaneously with different step sizes using clear aligners in vitro in order to provide a theoretical basis for the rational design of molar distalization. Methods:Clear aligners were designed to simultaneously distalize the maxillary first and second molars bilaterally, with rectangular attachments placed on the buccal surfaces of the first and second premolars, as well as the second molars. Based on different step sizes, the aligners were divided into three groups: Group A (0.15 mm per step), Group B (0.20 mm per step), and Group C (0.25 mm per step). Ten aligners were fabricated for each group using 0.76 mm thick polyethylene terephthalate glycol (PET-G) sheets. A three-dimensional force measurement system was used to measure the forces exerted on each tooth by the aligners, the first and second molars served as the target teeth and the remaining teeth as anchorage teeth. The three-dimensional force data were compared among the three groups.Results:In the mesiodistal direction, the forces on the central and lateral incisors were relatively small among all three groups, with no statistically significant differences ( P>0.05). However, significant differences were observed in the forces on the canines, first premolars, second premolars, first molars, and second molars ( P<0.05). The distal forces on the second molars in Groups B and C were (6.13±1.45) N and (6.83±1.58) N, respectively, significantly higher than that in Group A [(3.51±1.01) N] ( P<0.05). The distal force on the first molars in Group C [(6.62±0.89) N] was significantly higher than that in Groups A and B ( P<0.05). The mesial reactive forces on the first and second premolars in Groups B and C were significantly higher than those in Group A ( P<0.05). The mesial reactive force on the canines in Group C [(-2.98±1.33) N] was significantly higher than that in Group A [(-1.69±0.68) N] ( P<0.05), while there were no significant differences between Groups B and C in the forces on the canines, first premolars, and second premolars ( P>0.05). In the buccolingual direction, there were no statistically significant differences in the forces on the central and lateral incisors among three groups ( P>0.05), but significant differences were observed in the forces on the canines, second premolars, and second molars ( P<0.05). The buccolingual forces on the canines, second premolars, and second molars in Group B were (-0.56±0.54), (-2.07±0.95), (1.13±0.55) N, respectively, significantly higher than those in Group A ( P<0.05), but there were no significant differences compared to Group C ( P>0.05). Compared to the mesiodistal and buccolingual forces, the vertical forces on the target and anchorage teeth were relatively small in all three groups. Conclusions:When using 0.76 mm thick PET-G sheets to fabricate clear aligners for simultaneous molar distalization, a step size of 0.20 mm per step is recommended. To prevent buccal tipping of the molars during distalization, it is advisable to design lingual displacement for the molars and buccal displacement for the adjacent anchorage teeth to counteract the unfavorable forces, with attachments placed on the primary anchorage teeth.

Objective:To investigate the efficacy of intermittent pneumatic compression (IPC) combined with drugs in the prevention of lower extremity deep venous thrombosis (DVT) after joint replacement and its risk factors.Methods:A total of 80 patients receiving joint replacement surgery in Jinhua People's Hospital from January 2019 to December 2020 were included in this study. They were randomly divided into observation and control groups, with 40 patients in each group. To prevent lower extremity deep venous thrombosis, the control group was given low molecular weight heparin, and the observation group was given IPC in addition to DVT. The incidence of DVT post-surgery and coagulation function pre- and post-surgery were compared between the two groups. The incidence of adverse reactions was recorded in each group. In addition, 40 patients who developed DVT after joint replacement surgery from January 2019 to December 2020 (DVT group) and 40 patients who did not develop DVT (no DVT group) were included. The factors influencing the occurrence of DVT were analyzed by binary logistic regression.Results:The incidence of DVT in the observation group was significantly lower than that in the control group (5.00% vs. 20.00%, χ2 = 4.11, P < 0.05). At 7 days after surgery, prothrombin time, activated partial thromboplastin time, fibrinogen in the observation group were (11.73 ± 0.51) seconds, (27.05 ± 1.17) seconds, (3.89 ± 0.52) g/L, respectively, which were significantly lower than (12.03 ± 0.43) seconds, (27.65 ± 1.30) seconds, and (4.18 ± 0.59) g/L in the control group ( t = 2.84, 2.33, 2.17, all P < 0.05). There was no significant difference in the incidence of adverse reactions between observation and control groups (5.00% vs. 2.50%, χ2 = 0.00, P > 0.05). There were significant differences in age, body mass index, history of hypertension, and operative time between patients with DVT and those without DVT ( χ2 = 4.11, 5.16, 4.71, 8.65, all P < 0.05). Logistic regression analysis showed that age ( OR = 1.57, 95% CI = 1.239 - 2.014), body mass index ( OR = 6.71, 95% CI = 1.298 - 34.794), history of hypertension ( OR = 3.23, 95% CI = 1.980 - 5.296), operative time ( OR = 6.29, 95% CI = 2.058 - 19.225) were independent risk factors for DVT after joint replacement surgery (all P < 0.05). Conclusion:There are many factors that influence the occurrence of DVT after joint replacement surgery. Intermittent pneumatic compression combined with drugs for prevention of lower extremity DVT is safe and effective.

BACKGROUND:Cartilage injury is stil one of the clinical problems difficult to be treated completely so far. Recently, the discovery of synovial mesenchymal stem cells (SMSCs) has brought about the new hope to cartilage repair.
OBJECTIVE:To explore the process concerning SMSCs-based therapy for cartilage repair in the past few years, such as the characteristics of SMSCs, culture conditions, preclinical and clinical studies, and then to summarize the literatures published in recent years.
METHODS:A computed-based online search of PubMed and SpringerLink databases was performed using the key words of“synovial mesenchymal stem cells, cartilage repair”for literatures published from January 1993 to May 2013.
RESULTS AND CONCLUSION:Final y, 37 articles were included. SMSCs have a greater proliferative capability, colony-forming potential and chondrogenic potential than other mesenchymal stem cells. The diseases such as osteoarthritis and rheumatoid arthritis can influence the characteristics of SMSCs. Numerous articles have aimed at the studies of cellculture in vitro and celltransplantation in vivo. However, the process of SMSCs therapy is mostly at its preliminary stage. Reports on its unique characteristics, optimal culture conditions and the high-quality clinical studies are stil largely lacking. In a word, though further studies are needed, SMSCs appear to be a promising cellsource for cartilage repair in the future.

BACKGROUND: Bone marrow mesenchymal stem cells (MSCs) have been widely accepted by medical investigators due to their advantages including easy obtaining, minimal invasion, with infinite proliferation and multi-differential potential, and without immunological rejection in the autologous transplantation. OBJECTIVE: The goal of this study is to isolate and purify rat bone marrow MSCs in vitro, so as to observe the effects of different concentrations of serum containing kidney-tonifying and blood-activating Chinese herbs on the in vitro proliferation of rat bone marrow MSCs.DESIGN: A randomized controlled animal experiment.SETTING: Hip Center, First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine.MATERIALS: Forty healthy male SD rats of SPF grade, weighing 170 to 180 g, were provided by the Laboratory Animal Center, Guangzhou University of Traditional Chinese Medicine. The protocol was performed in accordance with ethics guidelines for the use and care of animals. The involved rats were divided into 4 groups by random digit table with 10 rats in each: normal control group, high-, middle-, and low-concentration groups. METHODS: This study was performed at the Laboratory Animal Center, Guangzhou University of Traditional Chinese Medicine between January and March 2005. Rat bone marrow MSCs were isolated and purified by Percoll density gradient centrifugation, and cultured in vitro to establish rat bone marrow MSCs culture system. Rats in the high-, middle-, and low-concentration groups were intragastrically administrated with 4.4, 2.2 and 1.1 g/kg serum containing kidney-tonifying and blood-activating Chinese herbs, which equaled to 20, 10 and 5 times of adult dosage, respectively. Rats in the normal control group were intragastrically administrated with purified water for 1 week. One hour after the last administration, 6 mL blood was taken from abdominal aorta of each rat under the aseptic condition. Then, it was centrifuged at 2 000 r/min for 15 minutes, and meanwhile serum was collected. 10% rat serum containing kidney-tonifying and blood-activating Chinese herbs was added to the medium in the high-, middle-, and low-concentration groups, while 10% fetal bovine serum was added in the normal control group. MAIN OUTCOME MEASURES: ① MSCs growth status; ② MSCs morphology was observed by HE staining and Giemsa's staining; ③ MSCs antigen expression was detected by an immunocytochemical method; ④ Effects of different concentrations of serum containing kidney-tonifying and blood-activating Chinese herbs on MSCs growth.RESULTS: ①The primarily cultured bone marrow MSCs began to adhere to the wall 24 hours later and 80% of them reached the confluence 7 days later. ② MSCs took appearance in long shuttle shape or polygon. These cells were little. Nuclei were located in the middle part of cells or a little deviation. The ratio of nucleus to cytoplasm was a little high. ③CD44 expression was found in the cytoplasm of mononuclear cells, and colored blue. Partial MSCs expressed c-Kit. Their cytomorphology and phenotypic expression have the characteristics of MSCs. ④Three days after serum containing kidney-tonifying and blood-activating Chinese herbal medicine being added to high-, middle-, and low-concentration groups, the number of bone marrow MSCs was dose-dependently increased as compared with that in the normal control group. CONCLUSION: Serum containing kidney-tonifying and blood-activating Chinese herbs promotes the in vitro proliferation of bone marrow MSCs.

0.05).However,there existed a better effect on relieving TCM syndrome in group A than that in group B,though the effect of group A on relieving pain was inferior to that of group B(P