Application of micro-lecture based on virtual reality technology in the standardized residency training in department of orthopedics / 中华医学教育探索杂志

Objective:To explore the application effect of micro-lecture based on virtual reality technology on the standardized residency training in the department of orthopedics.Methods:A total of 40 trainees who received standardized residency training in department of orthopedics from December 2019 to August 2020 were selected and randomly divided into control group and experimental group, with 20 cases in each group. For the same orthopedic teaching content, the control group received the conventional training, and the experimental group received micro-lecture teaching based on digital virtual reality technology. And the teaching effect of the two groups and the feedback of the trainees on the teaching were compared. SPSS 22.0 was used for t test. Results:Compared with the students in the control group, the trainees in the experimental group had better performance in theoretical knowledge, comprehension of surgery, and clinical skills, and the difference was statistically significant ( P<0.05). Compared with the control group, the trainees in the experimental group scored higher in satisfaction with class interest [(9.69±0.28) vs. (9.24±0.42)] and participation [(4.38±0.43) vs. (4.03±0.62)], with statistically significant differences ( P<0.05). Conclusion:For the standardized residency training in the department of orthopedics, micro-lecture teaching based on virtual reality technology is more conducive to improving students' academic performance and clinical skills compared with traditional teaching, and increasing the interest and participation of students in the process of standardized residency training.

Responses of annual herb plant community characteristics to increased precipitation and reduced wind velocity in semiarid sandy grassland.

Changes in precipitation regimes and wind velocity tend to alter structure and composition of the annual herb plant community, with consequent effects on ecological functioning and biodiversity maintenance. We examined the effects of increased precipitation and reduced wind velocity on annual herb plant community characteristics via a manipulative experiment from the middle of April to middle of August, 2016. There was significant increment in species richness with increased precipitation from June to August, and there were interactive effects between increased precipitation and reduced wind velocity especially in June and the end of July. From June to August, increased precipitation, reduced wind velocity as well as their interaction stimulated sandy plant community development. There was considerable elevation in plant coverage with increased precipitation, and also there was an interactive effect of increased precipitation with 20% reduced wind velocity. However, reduced wind velocity caused more significant stimulation (p < .01) in plant height. Moreover, dominant plants, Salsola collina, Bassia dasyphylla, and Setaria viridis, contributed equally to the elevated community coverage with increased precipitation, whereas S. collina occupied a much larger proportion on the augment of community height compared with the other two species under the increased precipitation and reduced wind velocity. Elevated Shannon-Wiener index was detected with increased precipitation in June and July. Furthermore, increased precipitation and reduced wind velocity enhanced aboveground and belowground biomass, respectively. These species traits-in structuring and composing plant community were suggested to be conducive to deep understanding the plant functioning and dynamics under global changing precipitation regimes and atmospheric wind velocity scenarios.

Operative treatment of delayed acetabular fractures through combined anterior and Kocher-Langenbeck approaches / 中华外科杂志

Objective@#To discuss the clinical outcomes of treating delayed acetabular fractures by combined anterior and posterior approach.@*Methods@#A retrospective analysis was conducted of 31 delayed acetabular fractures from February 2012 to February 2017 in the First Affiliated Hospital of Chongqing Medical University, including 18 males and 13 females with age of 48.5 years(23 to 67 years) .The injury to the operation time was 35.9 days(22 to 183 days). Of these 31 cases, there were 6 cases of transverse and posterior wall fracture, 8 cases with anterior column+ posterior half transverse fracture, 12 cases with double column fracture and 5 cases of "T" type fracture according to Letournel-Judet classification.All fractures were treated combined anterior and Kocher-Langenbeck approaches, including 13 cases of ilioinguinal approach+ Kocher-Langenbeck(K-L approach), 4 cases of extensile acetabular approach, 7 cases of stoppa approach + K-L approach and 7 cases of side rectus femoris approach.Correlation was analyzed by Pearson correlation regression testing.@*Results@#Follow up to August 2017, all patients were followed up with 36.0 months(from 6 to 55 months). As calculated, the restorational effect was positively with result of the X-ray film and the clinical effect(r=0.823, 0.856; both P<0.05). The evaluation was conducted with Matta′s reduction criteria: there were 11 cases classified as anatomic reduction(35.5%), 13 cases as satisfactory reduction(41.9%), and 7 cases as unsatisfactory reduction(22.6%). Excellent and good rate was 77.4%. Functional reductions were categorized by the standard of Matta hip score: 8 excellent cases(25.8%), 11 good cases(35.5%), 8 fail cases(25.8%), and 4 poor cases(12.9%).@*Conclusion@#The treatment of delayed acetabular fracture by combined anterior and posterior approach can fully exposure the anterior and posterior acetabular fcloumns, which is beneficial to the release and fixation of the old acetabular fractures.

Lumbopelvic fixation of vertically unstable Tile type C pelvic fractures combined with complex sacral fractures / 中华创伤杂志

Objective To evaluate the clinical outcomes of lumbopelvic fixation of vertically unstable Tile type C pelvic fractures combined with complex sacral fractures.Methods A prospective study was made on 21 cases of vertically unstable type C pelvic fractures combined with complex sacral fractures admitted between May 2014 and December 2015.There were 10 males and 11 females, with a mean age of 35.9 years (range, 14-59 years).Tile classification of pelvic fractures was type C1 in five cases, type C2 in four and type C3 in 12.Denis classification of sacral fractures was zone I in five cases, zone Ⅱ in seven and zone Ⅲ in nine.Twelve cases had neurological deficits.Operation time, intraoperative blood loss, bone healing time, pelvis vertical displacement and postoperative complications were recorded.Vertical displacement and functional outcome were assessed by Matta method and Majeed score respectively.Results All cases were followed up for (12.5±5.4)months (range, 7-26 months).Operation time was (108.0±49.4) min (range, 64-225 min).Intraoperative blood loss was 150-3 000 ml[400(225-500)ml].All fractures were healed at (19.0±4.6) weeks (range, 15-32 weeks).Vertical displacement of the pelvis was (8.76±5.46)mm (2.54-21.80 mm) before operation and (4.20±3.22)mm (0-12.57 mm) after lumbopelvic fixation (P<0.05), showing the reduction distance of-4.45-17.86 mm [4.09(1.74-5.58)mm].According to the Matta method, the results were excellent in 13 cases, good in six, and fair in two, with the excellent and good rate of 90%.Majeed score evaluation at last follow-up was 51-98 points and the results were excellent in nine cases, good in nine, fair in two and poor in one, with the excellent and good rate of 86%.Deep infection occurred in two cases who were cured by debridement and antibiotics, and the internal instruments of the two cases were removed after fracture healing.Screw loosening occurred in five cases with no evidence of screw breakage.Four cases complained of foreign body sensation and discomfort in sacral area due to the prominence of the iliac hardware.Four cases had limited range of motion of the lumbar spine, especially in anterior flexion range, and lumbar range of motion was recovered in three of them after removal of the internal fixator.Conclusion Lumbopelvic fixation can restore vertical stability of the pelvis, but removal of the internal fixator is suggested after fracture healing due to the high rate of screw loosening.

Anti-proliferation effect of zoledronic acid on human colon cancer line SW480

OBJECTIVE@#To investigate the anti-proliferation effect and mechanism of zoledronic acid (ZOL) on human colon cancer line SW480.@*METHODS@#SW480 cells were treated with 0, 12.5, 25, 50, 100 and 200 μmoL/L of ZOL for 48 h, and CCK-8 assay was employed to obtain the survival rate of SW480 cells. SW480 cells were treated with 25 μmoL/L of ZOL for 0, 12, 24, 48 and 72 h, and then the survival rate was obtained. SW480 cells of the ZOL group were treated with 25 μmoL/L of ZOL for 48 h, while cells of the CsA + ZOL group were pretreated with 10 μmoL/L of CsA for 0.5 h and then treated with 25 μmoL/L of ZOL for 48 h. Then the survival rates of SW480 cells of the control group, ZOL group and CsA + ZOL group were determined. Flow cytometry was employed to detect the apoptosis rate and the mitochondrial transmembrane potential (△Ψm) of the three groups and Western blot was used to detect the expressions of cyt C in the cytosol of the three groups.@*RESULTS@#ZOL inhibited the proliferation of SW480 cells, and the inhibition rate positively correlated with the concentration of ZOL and the action time (P < 0.01). The cell survival rate and the △Ψm of the ZOL group were greatly lower than those of the control group, while the apoptosis rate and the expression of cyt C in the cytosol were obviously higher than those of the control group. All the differences showed distinctly statistical significances (P < 0.01). The cell survival rate and the △Ψm of the CsA + ZOL group were all lower than those of the control group, but substantially higher than those of the ZOL group; while the apoptosis rate and the expression of cyt C in the cytosol were higher than those of the control group, but distinctly lower than those of the ZOL group. All the differences were statistically significant (P < 0.01).@*CONCLUSIONS@#ZOL can induce the apoptosis in human colon cancer line SW480 and then inhibit the proliferation of SW480 cells directly by opening the mitochondrial permeability transition pore abnormally, decreasing △Ψm, and releasing the cyt C into the cytosol. And the effect enhances with the increases of the concentration of ZOL and the action time.

Anti-proliferation effect of zoledronic acid on human colon cancer line SW480

Objective: To investigate the anti-proliferation effect and mechanism of zoledronic acid (ZOL) on human colon cancer line SW480. Methods: SW480 cells were treated with 0, 12.5, 25, 50, 100 and 200 μmoL/L of ZOL for 48 h, and CCK-8 assay was employed to obtain the survival rate of SW480 cells. SW480 cells were treated with 25 μmoL/L of ZOL for 0, 12, 24, 48 and 72 h, and then the survival rate was obtained. SW480 cells of the ZOL group were treated with 25 μmoL/L of ZOL for 48 h, while cells of the CsA + ZOL group were pretreated with 10 μmoL/L of CsA for 0.5 h and then treated with 25 μmoL/L of ZOL for 48 h. Then the survival rates of SW480 cells of the control group, ZOL group and CsA + ZOL group were determined. Flow cytometry was employed to detect the apoptosis rate and the mitochondrial transmembrane potential (▵Ψm) of the three groups and Western blot was used to detect the expressions of cyt C in the cytosol of the three groups. Results: ZOL inhibited the proliferation of SW480 cells, and the inhibition rate positively correlated with the concentration of ZOL and the action time (P < 0.01). The cell survival rate and the ▵Ψm of the ZOL group were greatly lower than those of the control group, while the apoptosis rate and the expression of cyt C in the cytosol were obviously higher than those of the control group. All the differences showed distinctly statistical significances (P < 0.01). The cell survival rate and the ▵Ψm of the CsA + ZOL group were all lower than those of the control group, but substantially higher than those of the ZOL group; while the apoptosis rate and the expression of cyt C in the cytosol were higher than those of the control group, but distinctly lower than those of the ZOL group. All the differences were statistically significant (P < 0.01). Conclusions: ZOL can induce the apoptosis in human colon cancer line SW480 and then inhibit the proliferation of SW480 cells directly by opening the mitochondrial permeability transition pore abnormally, decreasing ▵Ψm, and releasing the cyt C into the cytosol. And the effect enhances with the increases of the concentration of ZOL and the action time.

[Reactive oxygen species scavenger protects cardiac cells against injuries induced by chemical hypoxia].

OBJECTIVE: To investigate the protective effect of reactive oxygen species (ROS) scavenger, N-acetyl-L-cysteine (NAC), against H9c2 cardiomyocytes from injuries induced by chemical hypoxia. METHODS: H9c2 cells were treated with cobalt chloride (CoCl2), a chemical hypoxia-mimetic agent, to establish the chemical hypoxia-induced cardiomyocyte injury model. NAC was added into the cell medium 60 min prior to CoCl2 exposure. The cell viability was evaluated using cell counter kit (CCK-8), and the intercellular ROS level was measured by 2', 7'- dichlorfluorescein-diacetate (DCFH-DA) staining and photofluorography. Mitochondrial membrane potential (MMP) of the cells was observed by Rhodamine123 (Rh123) staining and photofluorography, and the ratio of GSSG/ (GSSG+GSH) was calculated according to detection results of the GSSG kit. RESULTS: Exposure of H9c2 cardiomyocytes to 600 micromol/L CoCl2 for 36 h resulted in significantly reduced cell viability. Pretreatment with NAC at the concentrations ranging from 500 to 2000 micromol/L 60 min before CoCl2 exposure dose-dependently inhibited CoCl2-induced H9c2 cell injuries, and obviously increased the cell viability. NAC at 2000 micromol/L obviously inhibited the oxidative stress induced by CoCl2, decreased the ratio of GSSG/(GSSG+GSH), increased ROS level, and antagonized CoCl2-induced inhibition on MMP. CONCLUSION: NAC offers obvious protective effect on H9c2 cardiomyocytes against injuries induced by chemical hypoxia by decreasing in the ratio of GSSG/(GSSG+GSH) and ROS level and ameliorating MMP.

Comparison of efficacies of two fixation methods in treatment of complex intra-articular fracture of the distal radius / 中华创伤杂志

Objective To compare the efficacies and indications of locking compression plate (LCP) and external fixator plus Kirschner wires in treatment of complex intra-articular fracture of the dis-tal radius. Methods Ninety-eight patients with complex intra-articular fractures of the distal radius were treated with volar LCP or external fixator plus Kirschner wires, the efficacies of which were evaluated by comparing the grasping force and wrist function of the patients. Results All the patients were fol-lowed up for an average of 12.4 months, which showed fracture healing in all the patients. According to the wrist function assessment system of New York Orthopedic Hospital (1990), there was no statistical difference in the efficacy of LCP and external f'lxator plus Kirschner wires in treatment of types C1 or C2 fractures (P > 0.05), while the efficacy of external fixator plus Kirschner wires was significantly superior to that of LCP in treating type C3 fracture (P < 0.05). Conclusions For types C1 or C2 intra-articu-lar fractures of the distal radius, the efficacies of LCP and external fixator plus Kirschner wires are simi-lar, while the efficacy of external fixator plus Kirschner wires is superior to that of LCP in treating type C3 intra-articular fracture of the distal radius.

Analytical comparison of different parts of Radix Angelicae Sinensis by gas chromatography coupled with mass spectrometry.

The three parts of Radix Angelicae Sinensis (Danggui) were reported to have different therapeutic effects. In order to investigate their chemical compositions of different parts of Danggui, gas chromatography-mass spectrometry (GC-MS) combined with chemometrics data analysis was applied to provide a more detailed study. Subwindow factor analysis (SFA) and a modified augmented evolving window orthogonal projection (AEWOP) method were used to resolve the batch GC-MS data sets from the Danggui samples. Then, t-test, Wilcoxon rank sum test, and principal component analysis (PCA) were applied to carry out the comparison job. The results indicate which components are found to have significant differences among the three parts. These findings may be helpful for further research of the pharmacological activities of Danggui.

Human bronchial epithelial cells express and secrete MMP-12.

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins, which may be responsible for enlargement of alveoli in chronic obstructive pulmonary disease (COPD) and remodeling of pulmonary tissue associated with chronic asthma. Here, we provide novel evidence that MMP-12 is expressed and secreted by normal human bronchial epithelial cell cultures (NHBECs) and reveal the regulation of MMP-12 gene expression by tumor necrosis factor-alpha (TNF-alpha), epidermal growth factor (EGF), and interferon gamma (IFN-gamma). Reverse transcription-polymerase chain reaction analyses demonstrated MMP-12 mRNA presence in unstimulated differentiated NHBEC cultures. Cultures stimulated independently with EGF or IFN-gamma failed to alter MMP-12 mRNA abundance, while TNF-alpha, TNF-alpha+EGF, or TNF-alpha+IFN-gamma elicited relatively early (6 h) peak increases in MMP-12 mRNA levels. Western blot analyses specifically indicated the presence of MMP-12 in differentiated NHBEC-conditioned media. These findings indicate that the bronchial epithelium may be an important source of elastolytic activity in COPD and tissue remodeling in chronic asthma.

Mutations in Aspergillus fumigatus resulting in reduced susceptibility to posaconazole appear to be restricted to a single amino acid in the cytochrome P450 14alpha-demethylase.

To better understand the molecular basis of posaconazole (POS) resistance in Aspergillus fumigatus, resistant laboratory isolates were selected. Spontaneous mutants arose at a frequency of 1 in 10(8) and fell into two susceptibility groups, moderately resistant and highly resistant. Azole resistance in A. fumigatus was previously associated with decreased drug accumulation. We therefore analyzed the mutants for changes in levels of transcripts of genes encoding efflux pumps (mdr1 and mdr2) and/or alterations in accumulation of [(14)C]POS. No changes in either pump expression or drug accumulation were detected. Similarly, there was no change in expression of cyp51A or cyp51B, which encode the presumed target site for POS, cytochrome P450 14alpha-demethylase. DNA sequencing revealed that each resistant isolate carried a single point mutation in residue 54 of cyp51A. Mutations at the same locus were identified in three clinical A. fumigatus isolates exhibiting reduced POS susceptibility but not in susceptible clinical strains. To verify that these mutations were responsible for the resistance phenotype, we introduced them into the chromosome of a POS-susceptible A. fumigatus strain under the control of the glyceraldehyde phosphate dehydrogenase promoter. The transformants exhibited reductions in susceptibility to POS comparable to those exhibited by the original mutants, confirming that point mutations in the cyp51A gene in A. fumigatus can confer reduced susceptibility to POS.