Objective To determine the effect of unfractionated heparin (UFH) on lipopolysaccharide (LPS)-induced expression of chemokines and nuclear factor-κB (NF-κB) signaling pathway. Methods Human pulmonary microvascular endothelial cells (HPMECs) were cultured in vitro, and the cells between passages 3 and 5 were used in the experiments. The cells were divided into control group, LPS challenge group, 1 kU/L or 10 kU/L UFH+LPS group, and NF-κB inhibitor N-tosyl-L-lysyl chloromethyl-ketone (TLCK) group (TLCK+LPS group). HPMECs in LPS challenge group were treated with 10 mg/L LPS. UFH pretreatment with different dosages groups were treated with 1 kU/L or 10 kU/L UFH 15 minutes before LPS challenge. Cells in the TLCK+LPS group were treated with 10 μmol/L of TLCK 30 minutes before the addition of LPS, and HPMECs in control group were treated with an equal volume of phosphate-buffered saline (PBS) instead. The cells were harvested 1 hour after LPS challenge, and the nuclear translocation of NF-κB was determined by immunofluorescence assay to detect the effect of UFH on NF-κB activation. The levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in cell culture supernatants were determined by enzyme linked immunosorbent assay (ELISA) 3 hours and 6 hours after LPS challenge to detect the effect of UFH on LPS induced expression of chemokines and its mechanism of effect on NF-κB signaling pathway in HPMECs. Results ① In the control group, NF-κB was mostly located in the cytosol as shown by immunofluorescence. Treatment of HPMECs with LPS significantly increased the translocation of NF-κB from the cytosol to nucleus. UFH suppressed LPS-induced NF-κB activation both in 1 kU/L and 10 kU/L dosages, and 10 kU/L UFH gave even better results. ② Compared with control group, the levels of IL-8 and MCP-1 in the supernatants in LPS challenge group were significantly increased at 3 hours and 6 hours after LPS challenge [IL-8 (ng/L): 387.1±26.4 vs. 23.8±8.1 at 3 hours, 645.5±69.6 vs. 125.7±18.7 at 6 hours; MCP-1 (ng/L): 3 654.9±467.9 vs. 721.6±61.3 at 3 hours, 8 178.5±792.6 vs. 1 324.7±148.7 at 6 hours, all P < 0.05]. Compared with that of LPS challenge group, in 1 kU/L and 10 kU/L UFH pretreatment groups, the levels of IL-8 and MCP-1 were significantly decreased [IL-8 (ng/L): 315.3±24.8, 275.8±31.1 vs. 387.1±26.4 at 3 hours, 557.8±43.3, 496.9±38.7 vs. 645.5±69.6 at 6 hours; MCP-1 (ng/L): 2 924.1±267.9, 2 668.3±522.6 vs. 3 654.9±467.9 at 3 hours, 7 121.7±557.2, 6 563.9±576.4 vs. 8 178.5±792.6 at 6 hours, all P < 0.05]. The results indicated that 10 kU/L UFH yielded better results. However, inhibition study using the known NF-κB inhibitor TLCK could decrease LPS-induced increase in IL-8 and MCP-1 levels [IL-8 (ng/L): 162.4±21.3 vs. 387.1±26.4 at 3 hours, 274.1±22.6 vs. 645.5±69.6 at 6 hours; MCP-1 (ng/L): 1 478.2±138.5 vs. 3 654.9±467.9 at 3 hours; 3 667.6±259.4 vs. 8 178.5±792.6 at 6 hours, all P < 0.05]. Conclusions The levels of IL-8 and MCP-1 were increased obviously in LPS treated HPMECs. UFH might suppress LPS-activated NF-κB signaling pathway, contributing to the inhibitory effects of chemokines in HPMECs.

Objective To investigate the efficacy and safety of Shuo Tong ureteroscopy in the treatment of upper ureteric stones.Methods The data of 832 patients,who underwent Shuo Tong ureteroscopy combined with holmium laser for the treatment of upper ureteric stones were collected between July 2014 and February 2017.The patients accepted general anesthesia under lithotomy position.After dilating the ureter,a ureteral access sheath was inserted along the guide wire.Finally,stones were broken and clean up by Shuo Tong ureteroscope.According to the stone size,823 patients were divided into ≤2.0 cm group (n=112,13.6％),2.1-3.0 cm group (n =395,48.0％),3.1-4.0 cm group (n =257,31.2％),＞ 4.0 cm group (n =59,7.2％)The stone free rate(SFR) and post-operative complications were observed.Results Among 983 operations,663 cases accepted one-stage operations and 160 cases accepted second stage operations.the operative time and postoperative hospital stay were 23-145 min(mean 74.8 ± 35.3) and 1-5 days(mean 1.9 ±0.8),respectively.The SFR in the first day and one month after operation was 75.6％ and 83.8％,respectively.The stone free rate in each group were 89.3％,82.5％,61.1％,52.5％ at first day after operation respectively(P ＜ 0.05).While,the SFR after one month were 95.5％,87.6％,72.0％,61.0％ in each group,respectively(P ＜ 0.05).Fever rate after operation was 11.1％,ureteral injury rate was 1.9％,severe hematuria rate was 0.6％,stone street formation rate was 1.2％,perirenal hematoma rate was 0.4％.All patients were improved after conventional treatment.Conclusion Shuo Tong ureteroscopy is a safe treatment with high stone free rate for upper ureteric stones.

Using novel virtual reality (VR) technology to carry out the construction of clinical medical examination question bank, while deepening the reform of clinical medical course examination, it continues to innovate the medical professional evaluation system and improve the flexibility, diversity and scientificity of clinical medicine in teaching and assessment. It is of great and far-reaching significance to improve the teaching level and the quality of medical education in medical colleges and universities. This paper analyzes and discusses the necessity and feasibility of building a clinical medical examination question bank, and the advantages and prospects of integrating VR technology to carry out the construction of clinical medical examination question bank. At the same time, the exploration and practice of the examination question bank construction based on VR technology disscussed in detail would provide innovative thinking and reference for the clinical medical teaching and evaluation, medical personnel training and other aspects in China.

Objective:By detecting the level changes of CXC chemokine ligand 8(CXCL8)in acute myelogenous leukemia(AML)patients at different disease stages,to analyze its correlation with the clinical condition and prognosis of AML patients,and to explore the effect of CXCL8 in the bone marrow microenvironment on the occurrence and development of AML and the regulatory mech-anism of malignant biological behavior of AML cell lines,to provide novel reference for the basic research and clinical diagnosis and treatment of AML.Methods:Bone marrow specimens from AML patients at different disease stages were collected,and ELISA was used to detect the content of CXCL8;quantitative real-time PCR(qRT-PCR)was used to detect the expression of CXCL8-specific receptor CXCR1/2 in different AML cell lines.U937 cells were selected as the AML disease model,and different concentrations of exogenous rCXCL8 were intervened in U937 cells,and the morphological changes of the cells were observed under the microscope.BM-MSCs from newly diagnosed AML patients were co-cultured with U937 cells,and ELISA was used to detect the difference in the content of CXCL8 in the co-culture system;Annexin V/PI double staining flow cytometry was used to detect the effects of rCXCL8 and anti-CXCL8 on the apoptosis of U937 cells respectively,and Western blot was used to reveal the accompanying molecular protein mechanism.Results:The level of CXCL8 in newly diagnosed and relapsed AML patients was significantly higher than that in healthy people(P<0.05),the level of CXCL8 in relapsed stage of AML was significantly higher than that in other disease stages of AML(P<0.01),and the level of CXCL8 in AML patients with CR stage and no infection was significantly higher than that in healthy people(P>0.05).The content of CXCL8 in the co-culture system of BM-MSC and U937 cells and the level of CXCL8 mRNA in U937 cells in the co-culture system were significantly higher than those in the monoculture group without BM-MSC(P<0.05).Intervention of rCXCL8 in U937 cells could promote cell proliferation by up-regulating Bcl-2 expression and down-regulating Bax expression,and up-regulate the expression of CXCL8-specific receptors CXCR1/2.After antagonizing CXCL8(anti-CXCL8),it will induce U937 cell apoptosis by up-regulating of Bax expression and down-regulating of Bcl-2 expression while inhibiting the activation level of ERK1/2 signaling pathway.Conclusion:CXCL8 is closely related to the disease and prognosis of AML,and is an effective monitoring indicator for disease pro-gression and prognosis evaluation of AML patients.CXCL8 in the bone marrow microenvironment is an important chemokine for malig-nant proliferation and immune escape of leukemia cells.By antagonizing CXCL8,U937 cells can be induced to undergo apoptosis,whose mechanism may be related to the expression changes of Bcl-2 family proteins and the inhibition of ERK1/2 signaling pathway activation.

Objective:To investigate the expression level of flap endonuclease 1 (FEN1) in bone marrow mononuclear cells of patients with acute myeloid leukemia (AML) and its relationship with clinicopathologic features and therapeutic effect, so as to provide a new direction for disease monitoring and targeted therapy in AML patients.Methods:The data of 57 newly treated AML patients and 26 healthy individuals (the healthy control) from the First Clinical College of Guangdong Medical University and Fujian Medical University Union Hospital from November 2018 to December 2020 were retrospectively analyzed. Bone marrow samples of all subjects were collected. Quantitative real-time fluorescence polymerase chain reaction (qRT-PCR) was used to detect FEN1 mRNA expression in bone marrow mononuclear cells of all subjects. Bone marrow samples from 9 newly-diagnosed AML patients and 4 healthy controls were collected, and FEN1 protein expression level was detected by using Western blotting. Differences in FEN1 mRNA expression in AML patients achieving different therapeutic effects were compared among AML patients whose data with evaluable efficacy. AML patients were divided into high FEN1 expression group (≥ critical value) and low FEN1 expression group (< critical value), taking the median relative expression level of FEN1 mRNA as the critical value. The correlation of FEN1 expression level with clinicopathologic features, laboratory indicators, cellular and molecular genetic changes in AML patients at initial diagnosis was analyzed.Results:The median relative expression of FEN1 mRNA in newly treated AML patients was higher than that in healthy controls [0.696 (0.025-3.661) vs. 0.246 (0.013-1.237), Z = 1.75, P = 0.041]. Western blotting showed that the expression level of FEN1 protein in AML patients was higher than that in healthy controls. The relative expression of FEN1 mRNA in 15 recurrent AML patients was higher than that in 19 patients patients achieving complete remission (CR) [1.153 (0.047-4.172) vs. 0.259 (0.023-1.148), Z = 2.71, P = 0.009]. The proportion of patients with French-American-British(FAB) type M 5, fever at initial diagnosis and lymph node enlargement in FEN1 high expression group (32 cases) was higher than that in FEN1 low expression group (25 cases) (all P < 0.05). There were no significant differences in the proportion of gender, age, fatigue, pale skin mucosa and large liver and spleen of patients between the two groups (all P > 0.05). At initial diagnosis, the white blood cell count, lactate dehydrogenase, C-reactive protein and bone marrow primitive cell proportion in FEN1 high expression group were higher than those in FEN1 low expression group (all P < 0.05), and the hemoglobin and platelet count in FEN1 high expression group were lower than those in FEN1 low expression group (all P < 0.05). There were no significant differences in procalcitonin level, the proportion of chromosome karyotype, cytogenetic prognosis grade and patients with or without gene mutation between the two groups (all P > 0.05). Conclusions:FEN1 expression is up-regulated in AML patients and further increased in relapsed patients. FEN1 expression in AML patients is associated with adverse clinicopathological features and poor detection results of laboratory indicators, which may become indicators for disease monitoring in AML patients.

Objective:To investigate the expression level of small nucleolar RNA SNORD15A in bone marrow of patients with acute leukemia (AL) and its relationship with clinical characteristics and prognosis of patients.Methods:Bone marrow blood samples of 53 newly treated AL patients and 29 healthy subjects without clinical diagnosis of hematologic diseases or other malignant diseases (control group) at the Affiliated Hospital of Guangdong Medical University from March 2018 to December 2021 were collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative expression of SNORD15A in bone marrow blood mononuclear cells of the two groups. The median relative expression of SNORD15A (0.148) was used as the boundary, and AL patients were divided into low expression group (<0.148) and high expression group (≥0.148). The relationship between the expression level of SNORD15A and the clinical characteristics, clinical indicators and overall survival (OS) of AL patients was analyzed. Kaplan-Meier method was used for survival analysis and log-rank test was performed; Cox proportional hazards model was used for univariate and multivariate analyses of OS of patients.Results:The relative expression of SNORD15A was 0.148 (0.012-1.376) in newly treated AL patients and 0.921 (0.513-2.288) in the control group, and the difference was statistically significant ( Z = -6.85, P < 0.01). The differences in SNORD15A relative expression between patients with different prognostic stratification, efficacy and with or without fever and bleeding were statistically significant (all P < 0.05). The differences in platelet count, plateletcrit and albumin levels between SNORD15A low expression group and high expression group were statistically significant (all P < 0.05), and the differences in molecular biology and cytogenetic characteristics were not statistically significant (all P > 0.05). The patients in SNORD15A high expression group had better OS than the low expression group ( P < 0.05). The results of univariate Cox regression analysis showed that SNORD15A was an influencing factor for patients' OS ( HR = 0.063, 95% CI 0.005-0.766, P < 0.05); the results of multivariate Cox regression analysis showed that fatigue ( HR = 4.754, 95% CI 1.014-22.290), fever ( HR = 0.147, 95% CI 0.029-0.746) and hemoglobin ( HR = 0.970, 95% CI 0.944 -0.998) were independent influencing factors for OS (all P < 0.05). Conclusions:SNORD15A is lowly expressed in AL and may be an indicator for disease monitoring and prognostic assessment in AL patients.

Objective:To investigate and analyze the status quo of death cognition and hospice care attitude of clinical medical graduate students, to compare the differences between the two groups, and to explore the correlation between death cognition and hospice care attitude, so as to provide the reference for the reform and construction of death cognition and hospice care education in medical colleges and universities in China.Methods:A survey was carried out on 496 doctoral and postgraduate students majoring in clinical medicine by using the "Questionnaire of General Sociology Survey", the Chinese version of the "Death Attitude Profile Revised Scale", and the Chinese version of the "Frommelt Attitudes Toward Care of the Dying Scale Form B (FATCOD-B)" to investigate the death cognition and hospice care attitude of 496 doctoral and postgraduate students majoring in clinical medicine, and classified and compared the survey results of the two groups. The results of this study were statistically analyzed by t-test, Pearson correlation analysis and other statistical methods. Results:A total of 469 valid questionnaires were recovered after excluding 27 unqualified questionnaires. Statistical analysis showed that the scores of each dimension in the death attitude description scale of doctoral students were ranked as follows: approach acceptance (4.28±0.53), neutral acceptance (3.99±0.41), death avoidance (2.74±0.63), fear of death (2.65±0.57) and escape acceptance (2.47±0.69) the scores of postgraduates were ranked as neutral acceptance (3.96±0.52), approach acceptance (2.84±0.61), fear of death (2.78±0.65), death escape (2.62±0.73), escape acceptance (2.39±0.77). At the same time, the scores of hospice care attitude in the doctoral group were higher than those in the master group [(110.63±8.96) vs. (106.78±6.52)], and the difference was statistically significant ( P<0.001). In addition, the scores of "fear of death" and the scores of hospice care attitudes were negatively correlated with the scores of doctoral and master students ( r=-0.25, r=-0.21), while the scores of hospice care attitudes were positively correlated with the scores of "neutral acceptance" in death cognition ( r=0.50, r=0.32). However, the hospice care attitude scores of doctoral students were negatively correlated with the "death avoidance" scores in death cognition ( r=-0.27). Conclusion:Doctoral and postgraduate students have a certain awareness of hospice care, while their death cognition and hospice care attitude still need to be improved and strengthened from sociology, psychology, ethics and other perspectives. The above will promote the harmony between doctors and patients while meeting the needs of an aging society in China.