BACKGROUND: Posterior spinal fusion is a process of bone fusion under special anatomical and biological effects, which affects by many factors. With the development of bone tissue engineering, in vitro constructed tissue engineered bioactive periosteum provides a new approach for solving this problem. OBJECTIVE: To evaluate the effect of in vitro constructed tissue engineered bioactive periosteum in treating lumbar intertransverse process fusion in rabbits. METHODS: In vitro constructed tissue engineered bioactive periosteum was implanted into lumbar intertransverse process of 24 healthy adult New Zealand rabbits. Three different materials were implanted into 3 transverse process gaps (Left L_(4,5,6), Right L_(4,5,6) of each animal. Namely, bone marrow mesenchymal stem cells (BMSCs) combined pig small intestine submucosa (SIS) were implanted into the right L_(4,5) of rabbits in the composite scaffold group; pure SIS was implanted into the right L_(5,6) of rabbits in the pure scaffold group; and autogeneic ilium was implanted into the left L_(5,6) of rabbits in the autogeneic ilium group. All rabbits were sacrificed at 12 weeks after operation to perform gross, imaging and histological observation. RESULTS AND CONCLUSION: The gross observation showed that there had no significant difference between the composite scaffold and autogeneic ilium groups, but the difference was significant compared with the pure scaffold group. lmaging observation showed that the trabeculae was formed in lumbar intertransverse of rabbits in the composite scaffold and autogeneic ilium groups, however, no bone density could be seen in the pure scaffold group. Type I collagen and osteocalcin were strong positive expressed in the composite scaffold group, which had obvious difference to the autogeneic ilium group. No positive expression could be found in the pure scaffold group. It suggested that tissue engineered bioactive periosteum constructed by BMSCs combined with SIS is a well alternative to autogenous graft materials for spinal fusion.

Objective:To evaluate the role of connexin43 (Cx43) in sevoflurane anesthesia-induced cognitive dysfunction in aged rats.Methods:Fifty-two healthy male Sprague-Dawley rats, aged 18 months, weighing 400-500 g, were divided into 4 groups ( n=13 each) using a random number table method: control group (C group), sevoflurane group (SEV group), sevoflurane plus sh-NC group (SEV+ sh-NC group) and sevoflurane plus sh-Cx43 group (SEV+ sh-Cx43 group). Sevoflurane anesthesia model was established by inhaling 3% sevoflurane for 6 h. In SEV+ sh-NC group and SEV+ sh-CX43 group, sh-NC 5 nmol and sh-CX43 5 nmol were transfected into the lateral ventricles, respectively, at 1 day before sevoflurane anesthesia.Morris water maze test was performed at 30 min before anesthesia and 1, 2 and 3 days after the end of anesthesia, and the rats were sacrificed at each time point after Morris water maze test, the brains were removed, and the hippocampi were isolated for microscopic examination of the pathological changes and for determination of the expression of Cx43, cleaved caspase-3 and cleaved caspase-9 (by using Western blot), and contents of interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-6 (by enzyme-linked immunosorbent assay). Results:Compared with group C, the escape latency was significantly prolonged, and the number of crossing the original platform was reduced, and the expression of CX43, cleaved caspase-3 and cleaved caspase-9 was up-regulated, and the contents of IL-1β, TNF-α and IL-6 were increased in group SEV ( P<0.05). Compared with group SEV, the escape latency was significantly shortened, the number of crossing the original platform was increased, and the expression of CX43, cleaved caspase-3 and cleaved caspase-9 was down-regulated, the contents of IL-1β, TNF-α and IL-6 were decreased ( P<0.05), and the hippocampal pathological injury was reduced in group SEV+ sh-CX43, and no significant change was found in the indicators mentioned above in group SEV+ sh-NC ( P>0.05). Conclusion:Cx43 is involved in the pathophysiological mechanism of sevoflurane-induced cognitive dysfunction probably by inducing neuroinflammatory responses and cell apoptosis in aged rats.

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.