OBJECTIVEThe aim of this study is to investigate the effects of irradiation on the proliferation and differentiation of MC3T3-E1 osteoblastic cells.

METHODSMC3T3-E1 cells were irradiated 24 h after initial seeding. Gamma-radiation was administered at 0, 4, and 8 Gy as single doses by using a 60Co source. Cell proliferation was assessed at days 1, 3, 5, and 7 post-irradiation by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide assay. The collagen secretion of the cells was measured through sirius red staining at day 12 post-irradiation. The expressions of osteogenesis-related genes were assessed through real time fluorescence quantitative polymerase chain reaction at day 16 post-irradiation. The matrix mineralization caused by cells was evaluated through alizarin red staining at day 28 post-irradiation.

RESULTSThe cells exposed to 4 Gy or 8 Gy demonstrated significantly lower proliferation rates compared with the non-irradiated group. Doses of 4 Gy or more significantly inhibited the expressions of osteogenesis-related genes (Osterix and osteocalcin). Collagen secretion and cell mineralization were significantly reduced by the 8 Gy dose.

CONCLUSION60Co gamma-rays dose-dependently suppress the proliferation, collagen secretion, and mineralization of MC3T3-E1 cells. Furthermore, radiation seems to dose-dependently inhibit the expressions of osteogenesis-related genes of the cells.

Cell Differentiation ; Cell Line ; Cell Proliferation ; Humans ; In Vitro Techniques ; Osteoblasts ; Osteocalcin ; Osteogenesis

Objective:To investigate the effects of titanium surface modified by micro-arc oxidation (MAO)on the collagen secre-tion and the expression of osteogenesis-related genes of MC3T3-E1 cells.Methods:Pure titanium discs were divided into two groups:Titanium with modified surface by MAO(MAO group)and titanium with polished surface(PT group).Tissue culture polysty-rene plates (TC)were used as controls.Surface morphology of the samples was examined by field-emission scanning electron micros-copy(FESEM).Surface roughness of samples was measured by surface roughness meter.MC3T3-E1 cells were cultured on the sur-face of the samples and the collagen secretion on the samples was measured by sirius red-based colorimetric microassay after 12 days of culture.On day 16 of culture,the expression of osteogenesis-related genes was examined by RT-PCR.Results:A porous oxide layer was observed on the surface of MAO treated samples and the surface roughness was more than that of PT group(P<0.01 ). Cells in MAO group showed higher collagen secretion than in PT or TC groups(P<0.05).MAO treated surface induced higher OSX, COL-Iα1 and OPN expression than PT.Conclusion:MAO treated titanium surface may induce more collagen secretion of MC3T3-E1 cells than PT.

OBJECTIVE To study the pathogenic bacteria and its resistance to antibiotics in chronic suppurative otitis media. METHODS Secretion from 132 cases with chronic suppurative otitis media were cultured. Drug sensitivity tests were done to separate pathogenic bacteria. RESULTS 152 strains pathogenic bacteria were isolated from middle ear secretion. The main pathogenic bacteria were staphylococcus aureus (49 strains), pseudomonas aeruginosa (25 strains) and fungus (5 strains). Staphylococcus aureus was sensitive to fluorquinolones, and the sensitivity rate was 79.6 %. Pseudomonas aeruginosa was sensitive to fluoroquinolones and floxacin, and the sensitivity rates were 84 % and 64 %. CONCLUSION Staphylococcus aureus and pseudomonas aeruginosa are main pathogens of chronic suppurative otitis media in our region. Both of them are sensitive to fluorquinolones. Meanwhile, pseudomonas aeruginosa is also sensitive to ceftazidime of the third cephalosporins. So doctors should choose the sensitive antibiotics for treatment of the chronic suppurative otitis media, that may avoid the bacteria with drug resistance come into being. The fungus can not be neglected as the pathogen in chronic suppurative otitis media.

Objective The aim of this study is to investigate the effects of irradiation on the proliferation and differentiation of MC3T3-E1 osteoblastic cells. Methods MC3T3-E1 cells were irradiated 24 h after initial seeding. Gamma-radiation was administered at 0, 4, and 8 Gy as single doses by using a 60Co source. Cell proliferation was assessed at days 1, 3, 5, and 7 post-irradiation by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide assay. The collagen secretion of the cells was measured through sirius red staining at day 12 post-irradiation. The expressions of osteogenesis-related genes were assessed through real time fluorescence quantitative polymerase chain reaction at day 16 post-irradiation. The matrix mineralization caused by cells was evaluated through alizarin red staining at day 28 post-irradiation. Results The cells exposed to 4 Gy or 8 Gy demonstrated significantly lower proliferation rates compared with the non-irradiated group. Doses of 4 Gy or more significantly inhibited the expressions of osteogenesis-related genes (Osterix and osteocalcin). Collagen secretion and cell mineralization were significantly reduced by the 8 Gy dose. Conclusion 60Co γ-rays dose-dependently suppress the proliferation, collagen secretion, and mineralization of MC3T3-E1 cells. Furthermore, radiation seems to dose-dependently inhibit the expressions of osteogenesis-related genes of the cells.

Objective:To investigate the current situation of fall fear in elderly patients after operation of intertrochanteric fracture, analyze the influencing factors and build a prediction model.Methods:A prospective cohort study and convenient sampling method were used to select 303 elderly patients with intertrochanteric fracture after surgery in the Department of Orthopedics, Affiliated Hospital of Jining Medical University from January 2021 to December 2022 as the modeling group. According to the scores of fall fear when getting out of bed for the first time, they were divided into 211 cases in the fall fear group and 92 cases in the non-fall fear group. Multivariate Logistic regression was used to analyze the influencing factors of fall fear after operation of femoral intertrochanteric fracture in elderly patients, and a risk prediction score model was established. ROC curve was used to evaluate the differentiation of the model, calibration chart was used to evaluate the calibration degree of the model, and Bootstrap method was used for internal verification. Data of 81 elderly patients with intertrochanteric fracture treated from January to May 2023 were collected as a validation set for external verification of the model.Results:A total of 6 influencing factors were included in the prediction of fall fear risk model for elderly patients after operation of intertrochanteric fracture: gender ( OR = 3.229, 95% CI 1.672 - 6.401), number of co-existing diseases ( OR = 9.578, 95% CI 4.532 - 20.245), pain ( OR = 1.684, 95% CI 1.074 - 2.463), depression ( OR = 1.719, 95% CI 1.371 - 2.155), social support ( OR = 0.859, 95% CI 0.784 - 0.942), and ability to perform activities of daily living ( OR = 0.960, 95% CI 0.932 - 0.989) (all P<0.05). The area under ROC curve of the prediction model was 0.853, the sensitivity was 0.896, and the specificity was 0.663. The area under the externally verified ROC curve was 0.766, the sensitivity was 0.800, and the specificity was 0.645. The calibration curve was close to the reference curve in the model prediction, indicating that the model hasd a good prediction effect. Conclusions:The prediction effect of this model is good, and it can quickly predict the risk of fall fear in elderly patients after operation of intertrochanteric fracture, and provide a basis for medical personnel to provide timely intervention measures.