BACKGROUND: Implantation of bone marrow mesenchymal stem cells (BMSCs) is a potential alternative for promoting bone defects healing or osseointegration in osteoporosis. However, the reactive oxygen species (ROS) accumulated and excessive inflammation in the osteoporotic microenvironment could weaken the self-replication and multi-directional differentiation of transplanted BMSCs. METHODS: In this study, to improve the hostile microenvironment in osteoporosis, Poloxamer 407 and hyaluronic acid (HA) was crosslinked to synthetize a thermos-responsive and injectable hydrogel to load MnO2 nanoparticles as a protective carrier (MnO2 @Pol/HA hydrogel) for delivering BMSCs. RESULTS: The resulting MnO2 @Pol/HA hydrogel processed excellent biocompatibility and durable retention time, and can eliminate accumulated ROS effectively, thereby protecting BMSCs from ROS-mediated inhibition of cell viability, including survival, proliferation, and osteogenic differentiation. In osteoporotic bone defects, implanting of this BMSCs incorporated MnO2 @Pol/HA hydrogel significantly eliminated ROS level in bone marrow and bone tissue, induced macrophages polarization from M1 to M2 phenotype, decreased the expression of pro-inflammatory cytokines (e.g., TNFa, IL-1b, and IL-6) and osteogenic related factors (e.g., TGF-b and PDGF). CONCLUSION This hydrogel-based BMSCs protected delivery strategy indicated better bone repair effect than BMSCs delivering or MnO2 @Pol/HA hydrogel implantation singly, which providing a potential alternative strategy for enhancing osteoporotic bone defects healing.

Objective:To construct the competency evaluation index system for endoscopic specialized nurses and provide basis for training, assessment and performance evaluation of endoscopic specialized nurses.Methods:In March 2021, through literature review, research group discussion, expert interview and satisfaction questionnaire, the competency evaluation system for endoscopic specialized nurses was initially established. From March to December 2021, experts from four provinces were selected by convenient sampling for two rounds of Delphi expert consultation. The weight of each indicator was determined by the method of precedence chart and analytic hierarchy process.Results:Among two rounds of consultation, the effective recovery rates of the questionnaire were 86.36% (19/22) and 89.47% (17/19) respectively, and the authority coefficients of experts were 0.82 and 0.86 respectively. The Kendall concordance coefficients of experts' opinions on the first, second and third level indicators were 0.40, 0.50 and 0.48 respectively ( P<0.05) . The final index system included 4 first level indicators (professional knowledge, professional skills, professional development ability, personal characteristics) , 18 second level indicators and 73 third level indicators. Conclusions:The competency evaluation index system for endoscopic specialized nurses has high reliability, comprehensive and practical contents, and has certain reference significance for the management and training of endoscopic specialized nurses.

Objective:To investigate the efficacy and safety of geritinib in the treatment of acute myeloid leukemia (AML) with FLT3 mutation.Methods:The clinical data of 5 AML patients with FLT3 mutation who were diagnosed in the University of Hong Kong-Shenzhen Hospital, Shenzhen People's Hospital, Shenzhen Second People's Hospital, Shenzhen University General Hospital from March 2020 to April 2021 were retrospectively analyzed. Relapsed patients concurrently received two- or three-drug chemotherapy combined with geritinib. Blood routine was checked once a week; liver function and renal function were checked once every 2 weeks during treatment. Bone marrow puncture was performed once every 1 to 3 months to monitor the bone marrow morphology, minimal residual disease (MRD) and FLT3 mutation expression levels. The efficacy, side effects, overall survival of these patients were analyzed after treatment with geritinib.Results:The white blood cell was increased in all the 5 patients at the initial diagnosis. FLT3 mutations analysis showed FLT3-internal tandem duplication (ITD) (3 cases) and FLT-3 tyrosine-kinase domain (TKD) (2 cases). Among 5 patients, 1 patient was relapse-free with maintenance therapy of oral geritinib after hematological stem cell transplantation (HSCT) for 60 days; among other 4 relapsed and refractory patients, 1 female patient after pregnancy relapsed after transplantation and then achieved complete remission followed by the maintenance therapy with geritinib after oral geritinib, 1 16-year-old patient achieved treatment outcome close to the complete remission after treatment with geritinib, 1 patient achieved complete remission after treatment with geritinib, and then underwent haplo-HSCT followed by the maintenance therapy with geritinib and the other 1 relapsed patient achieved complete remission after treatment with geritinib. After transplantation, 3 patients receiving maintenance treatment of geritinib did not relapse. The main side effects included anemia, decreased neutrophil count, rash, and increased aminotransferase. The median follow-up time of 5 patients was 15 months (6-20 months). All 5 cases survived until the last follow-up in November 2021 and 4 patients were disease-free.Conclusions:Relapsed and refractory AML patients with FLT3 mutation can achieve complete remission after treatment with geritinib and get a chance for transplantation. Geritinib may reduce the risk of recurrence after transplantation and improve survival rate. No serious side effects occur in geritinib treatment.

Objective: To investigate the clinical application of differential subsampling with Cartesian ordering (DISCO) contrastenhanced (CE) magnetic resonance angiography for anterolateral thigh (ALT) flap transplantation, using operative findings as a reference. Materials and Methods: Thirty patients (21 males and nine females; mean age ± standard deviation, 45.5 ± 15.6 years) who were scheduled to undergo reconstruction with ALT flaps between June 2020 and June 2021 were included in the prospective study. Before ALT flap transplantation, patients were scanned using CE-DISCO imaging. All acquired DISCO images of the 60 lower limbs (both sides from each patient) were analyzed using maximum intensity projection and volume rendering methods. Two experienced radiologists were employed to examine the patterns of the lateral circumflex femoral artery (LCFA), its branches, and perforators and their skin termini, which were compared with the operative findings. Results: Using CE-DISCO, the patterns of the LCFA and its branches were clearly identified in all patients. Four different origins of the LCFA were found among the 60 blood vessels: type I (44/60, 73.3%), type II (6/60, 10.0%), type III (8/60, 13.3%), and type IV (2/60, 3.3%). Owing to a lack of perforators entering the skin, two patients did not undergo ALT flap transplantation. For the remaining 28 patients, the ALT flaps in 26 patients were successfully operated without flap reselection during the operation, while the remaining two patients underwent other surgical procedures due to the thin diameter of the perforator or injury of the perforator during the operation. The success rate of flap transplantation was 92.8% (26/28). All transplanted flaps exhibited good blood supply and achieved primary healing without infection or delayed healing. Conclusion CE-DISCO imaging can be an effective method for preoperative perforator imaging before ALT flap transplantation.

Concerning on the safety risks caused by electromagnetic interference of patients implanted with high-risk active implantable medical devices in the environment of domestic MUs, this study evaluates and focuses on the requirements of electromagnetic compatibility in domestic and international standards for rail transit vehicles, the main mechanism of risks caused by EMI, the actual measurement of environmental data in MUs and the working performance of various active implantables in the compartment. The test results shows that all kinds of active implantable medical device samples works normally in the CRH2A EMU in China, and there is still a large margin between the measured radiation emission in MU and the limit required by the standards.
China ; Electromagnetic Fields ; Electromagnetic Radiation ; Humans ; Pacemaker, Artificial ; Prostheses and Implants

Objective:To detect the contents of brain water, Na + , and K + and the permeability of blood brain barrier (BBB) of the rats with brain edema in traumatic brain injury (TBI) complicated by seawater drowning(SWD) at different time points, so as to analyze the time course changes of brain edema after the combined injury. Methods:A total of 216 SD rats were randomly divided into control group ( n=6), sham operation group ( n=14), TBI group ( n=98), and TBI+ SWD group ( n=98). The TBI + SWD rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. Dry-wet mass method was used to detect the content of brain water. Flame spectrophotometry method was used to detect the contents of Na + and K + . Evans blue (EB) staining method was used to detect BBB permeability. Results:In the TBI group, the contents of brain water and Na + began to rise obviously 12 h after injury, reached the peak 2-3 d after injury, and returned to the normal levels 14 d after injury. The content of K + showed a fall 12 h after injury, reached the lowest point in 2-3 d after injury, and was still at a lower level than normal in 7 d. The EB content showed double peaks in 3 h and 2 d after injury respectively, and the latter peak was higher. Compared with those in the TBI group, the contents of brain water, Na + , and EB in the TBI + SWD group were significantly increased, but the content of K + was obviously decreased. In the TBI + SWD group, the contents of brain water and Na + began to rise 3 h after injury, reached the peak at 12 h till 7 d after injury, and were still higher than the normal levels 14 d after injury. The content of brain K + showed an obvious fall 3 h after injury, reached the lowest point at 12 h till 3 d, and was still lower than the normal level 7 d after injury. The EB content increased obviously 3 h after injury, reached the peak at 12 h till 3 d after injury, and was still higher than the normal level 14 d after injury. Conclusion:SWD aggravates brain edema in TBI rats. TBI + SWD rats may develop severe cerebral edema in the early period after injury, which last for a longer time.

Objective:To evaluate the effects of mouse nerve growth factor (mNGF) on the brain water content and the expressions of β-amyloid precursor protein (β-APP) and neurofilament light polypeptide (NF-L) in rats with traumatic brain injury (TBI) complicated by seawater drowning (SWD). Methods:A total of 60 male rats were randomly divided into three groups: Sham group ( n=12), TBI+ SWD group ( n=24), and mNGF group ( n=24). The rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. The mNGF group was administered mNGF intraperitoneally; while the Sham group and the TBI+ SWD group were injected with an equivalent amount of normal saline. The brain water content was measured by using the dry-wet weight method. The pathological changes of the hippocampal tissue and the expressions of β-APP and NF-L were observed through hematoxylin-eosin (HE) staining and immunohistochemical (IHC) staining. Results:Brain water content in the mNGF group was similar to that in the TBI+ SWD group ( P>0.05). Compared with the TBI+ SWD group, the expressions of β-APP and NF-L in the hippocampal tissue of the mNGF group were significantly reduced. Conclusion:mNGF can reduce the expressions of β-APP and NF-L, and protect the neurons of the rats after TBI+ SWD.

Objective:To detect the contents of brain water, Na + , and K + and the permeability of blood brain barrier (BBB) of the rats with brain edema in traumatic brain injury (TBI) complicated by seawater drowning(SWD) at different time points, so as to analyze the time course changes of brain edema after the combined injury. Methods:A total of 216 SD rats were randomly divided into control group ( n=6), sham operation group ( n=14), TBI group ( n=98), and TBI+ SWD group ( n=98). The TBI + SWD rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. Dry-wet mass method was used to detect the content of brain water. Flame spectrophotometry method was used to detect the contents of Na + and K + . Evans blue (EB) staining method was used to detect BBB permeability. Results:In the TBI group, the contents of brain water and Na + began to rise obviously 12 h after injury, reached the peak 2-3 d after injury, and returned to the normal levels 14 d after injury. The content of K + showed a fall 12 h after injury, reached the lowest point in 2-3 d after injury, and was still at a lower level than normal in 7 d. The EB content showed double peaks in 3 h and 2 d after injury respectively, and the latter peak was higher. Compared with those in the TBI group, the contents of brain water, Na + , and EB in the TBI + SWD group were significantly increased, but the content of K + was obviously decreased. In the TBI + SWD group, the contents of brain water and Na + began to rise 3 h after injury, reached the peak at 12 h till 7 d after injury, and were still higher than the normal levels 14 d after injury. The content of brain K + showed an obvious fall 3 h after injury, reached the lowest point at 12 h till 3 d, and was still lower than the normal level 7 d after injury. The EB content increased obviously 3 h after injury, reached the peak at 12 h till 3 d after injury, and was still higher than the normal level 14 d after injury. Conclusion:SWD aggravates brain edema in TBI rats. TBI + SWD rats may develop severe cerebral edema in the early period after injury, which last for a longer time.

Objective:To evaluate the effects of mouse nerve growth factor (mNGF) on the brain water content and the expressions of β-amyloid precursor protein (β-APP) and neurofilament light polypeptide (NF-L) in rats with traumatic brain injury (TBI) complicated by seawater drowning (SWD). Methods:A total of 60 male rats were randomly divided into three groups: Sham group ( n=12), TBI+ SWD group ( n=24), and mNGF group ( n=24). The rat models were created on the basis of Marmarou′s weight-drop TBI modeling and instilling seawater into the trachea by syringe pump. The mNGF group was administered mNGF intraperitoneally; while the Sham group and the TBI+ SWD group were injected with an equivalent amount of normal saline. The brain water content was measured by using the dry-wet weight method. The pathological changes of the hippocampal tissue and the expressions of β-APP and NF-L were observed through hematoxylin-eosin (HE) staining and immunohistochemical (IHC) staining. Results:Brain water content in the mNGF group was similar to that in the TBI+ SWD group ( P>0.05). Compared with the TBI+ SWD group, the expressions of β-APP and NF-L in the hippocampal tissue of the mNGF group were significantly reduced. Conclusion:mNGF can reduce the expressions of β-APP and NF-L, and protect the neurons of the rats after TBI+ SWD.

To explore the basics of integrated curriculums and the reform plan of integrated organ-system based curriculum of clinical subjects, this paper takes the integrated musculoskeletal system based curriculum in the third semester for undergraduates majoring in clinical medicine as an example, elaborates on the following five aspects: the organ system-centered curriculum system, the integration of teaching content, curriculum implementation plans, curriculum advantages, major issues and measures for improvement. This paper puts forward some urgent problems such as writing teaching materials, changing teachers' traditional teaching concepts, arranging the course reasonably, achieving learning outcomes, and deepening the integration of knowledge in various subjects. It is also provides suggestions for building a coherent and complete teaching model and knowledge system of the integrated organ-system based curriculum, helping students better understand the organic relationships between various disciplines, and promoting the curriculum reform. The reform of the integrated organ-system based curriculum has achieved initial results.