Discussion on online teaching of prosthodontics during the outbreak of COVID-19 / 中华医学教育探索杂志

Prosthodontics is an important undergraduate course in stomatology. It's an unprecedented challenge for teachers to give theoretical lectures completely by online teaching methods. After several months of online teaching practice, a complete closed-loop online teaching mode of "pre-class, in-class and after-class" has been formed by using online teaching tools such as Tencent meeting, Superstar learning platform and WeChat. A comprehensive feedback and assessment mechanism has also been established. On the premise of the teaching quality, online teaching has also promoted the exploration and reform of the information-based teaching of prosthodontics course.

Effect of famine exposure on the risk of chronic disease in later life among population in Harbin / 中华流行病学杂志

Objective To study the relations between famine exposure and the risk of chronic diseases as diabetes mellitus,obesity,hypertension,coronary heart disease and stroke in the population of Harbin.Methods Our data was collected from the baseline survey-the China Kadoorie Biobank project (CKB) in Harbin.Retrospective cohort study design was used.Related risks on chronic diseases including diabetes mellitus,obesity,hypertension,coronary heart disease and stroke,were compared among the famine exposed or non-exposed people,respectively by logistic analysis method.Results After adjusted for factors as age,sex,physical activity,smoking,alcohol intake,diet,family history of diseases,it appeared that the factor ‘ famine exposure'had increased the risks of diseases as obesity (OR=1.204,95％CI:1.104-1.313,P＜0.01),hypertension (OR=1.315,95％CI:1.210-1.429,P＜0.01) and coronary heart disease (OR=1.495,95％CI:1.369-1.632,P＜0.01).The lower the age of population being exposed to famine,the greater the risk of the development of all kinds of chronic diseases.Conclusions Famine exposure appeared a risk factor for obesity,hypertension,and coronary heart disease.It is of great significance to ensure the life-long nutrition of the people,especially in the early and adolescent stages,to prevent obesity,hypertension,and coronary heart disease in their later lives.

Effect of famine exposure on the risk of chronic disease in later life among population in Harbin / 中华流行病学杂志

Objective To study the relations between famine exposure and the risk of chronic diseases as diabetes mellitus,obesity,hypertension,coronary heart disease and stroke in the population of Harbin.Methods Our data was collected from the baseline survey-the China Kadoorie Biobank project (CKB) in Harbin.Retrospective cohort study design was used.Related risks on chronic diseases including diabetes mellitus,obesity,hypertension,coronary heart disease and stroke,were compared among the famine exposed or non-exposed people,respectively by logistic analysis method.Results After adjusted for factors as age,sex,physical activity,smoking,alcohol intake,diet,family history of diseases,it appeared that the factor ‘ famine exposure'had increased the risks of diseases as obesity (OR=1.204,95％CI:1.104-1.313,P＜0.01),hypertension (OR=1.315,95％CI:1.210-1.429,P＜0.01) and coronary heart disease (OR=1.495,95％CI:1.369-1.632,P＜0.01).The lower the age of population being exposed to famine,the greater the risk of the development of all kinds of chronic diseases.Conclusions Famine exposure appeared a risk factor for obesity,hypertension,and coronary heart disease.It is of great significance to ensure the life-long nutrition of the people,especially in the early and adolescent stages,to prevent obesity,hypertension,and coronary heart disease in their later lives.

Effect of local application of insulin like growth factor-1 gelatin sponge complex on osseointegration around implant in osteoporosis rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of local application of insulin like growth factor-1 (IGF-1) absorbable gelatin sponge complex in implant fossa on osseointegration around implant in osteoporosis rats.</p><p><b>METHODS</b>Female SD rats, aged 4 months, were randomly individed into ovariectomy group (OVX group) and sham-ovariectomy group (sham-ovx group). The rats in OVX group (n = 15) were ovariectomized, and the rats in Sham-OVX group (n = 10) underwent Sham-ovariectomy. Eight weeks later, 5 rats in each group were randomly selected to confirm the osteoporosis model. The ovariectomized rats were randomly divided into osteoporosis group (OP group) and IGF-1 group after the model was successfully established, 5 rats in each group. Pure titanium implants were implanted in the distal part of right femoral epiphyseal in all groups. Absorbable gelatin sponge particles containing 10 µg IGF-1 were placed in the planting fossa in the IGF-1 group, and absorbable gelatin sponge particles without IGF-1 were used in OP group and sham-OVX group. The rats were sacrificed, and then the distal part of right and left femoral epiphyses were taken out to make undecalcified and decalcified tissue sections respectively after 8 weeks. Combined bone lamella width (CBLW) and implant bone contact rate (IBCR) around implant, trabecular width (TW) and trabecular area percentage (TA) around implant and in the cortical bone of left femoral epiphyses were observed by histomorphometric measurement.</p><p><b>RESULTS</b>The CBLW, IBCR, TW and TA around implant was (55.43 ± 3.50) µm, (81.79 ± 4.45) %, (57.73 ± 4.29) µm and (62.21 ± 7.42) % respectively in sham-OVX group, (60.22 ± 4.70) µm, (83.67 ± 6.63) %, (48.08 ± 3.63) µm and (58.20 ± 8.93) % respectively in IGF-1 group, and (37.11 ± 2.18) µm, (64.60 ± 5.44) %, (41.19 ± 2.93) µm and (42.21 ± 4.34) % respectively in OP group. The CBLW, IBCR and TW around implant had no differences between IGF-1 and sham-OVX group (P > 0.05), which were significantly higher than those in OP group (P < 0.05). The TW and TA of cortical bone in left distal femoral epiphyses was (60.85 ± 6.64) µm, (61.24 ± 6.98) % respectively in sham-OVX group, (38.68 ± 4.74) µm, (43.89 ± 7.76) % respectively IGF-1 group, (40.46 ± 5.38) µm, (44.63 ± 5.39) % respectively in OP group (P < 0.05). The TW and TA of cortical bone in left distal femoral epiphyses had no differences between IGF-1 group and OP group (P > 0.05), which were all significantly lower than those in sham-OVX group (P < 0.05).</p><p><b>CONCLUSIONS</b>The local application of IGF-1 gelatin sponge complex can increase bone tissue around implant and improve osseointegration in osteoporosis.</p>

Human synovial fluid promotes directed differentiation of bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Nowadays, growth factors are commonly used to induce bone marrow mesenchymal stem cells. However, this is a high-cost method with a great amount of growth factors. In addition, the chondrogenic potential of bone marrow mesenchymal stem cells wil decrease significantly with increasing times of culture. OBJECTIVE:To observe the directed differentiation of bone marrow mesenchymal stem cells co-cultured with human synovial fluid. METHODS:Human bone marrow mesenchymal stem cells were isolated and cultured by adherence screening method. The synovial fluid of the knee was aspirated from healthy volunteers by aseptic operation. Passage 3 human bone marrow mesenchymal stem cells were co-cultured with the fol owing media:synovial fluid+complete medium;synovial fluid+bone marrow mesenchymal stem cells+complete medium;bone marrow mesenchymal stem cells+complete medium. The morphology and growth of the cells were observed under an inverted microscope every day. At days 7, 14 and 21 of induction, toluidine blue staining and immunocytochemical staining were performed. RESULTS AND CONCLUSION:After co-culture with human synovial fluid, human bone marrow mesenchymal stem cells proliferated slowly, and varied from fusiform to oval or polygonal;toluidine blue and col agen II staining were positive. These findings indicate that the synovial fluid has a positive role in the chondrogenic differentiation of bone marrow mesenchymal stem cells. The synovial fluid may contain substances that promote the chondrogenic differentiation of bone marrow mesenchymal stem cells.

Optimizing the Imaging Protocol for Ex Vivo Coronary Artery Wall Using High-Resolution MRI: An Experimental Study on Porcine and Human

OBJECTIVE: To optimize the MR imaging protocol for coronary arterial wall depiction in vitro and characterize the coronary atherosclerotic plaques. MATERIALS AND METHODS: MRI examination was prospectively performed in ten porcine hearts in order to optimize the MR imaging protocol. Various surface coils were used for coronary arterial wall imaging with the same parameters. Then, the image parameters were further optimized for high-resolution coronary wall imaging. The signal-noise ratio (SNR) and contrast-noise ratio (CNR) of images were measured. Finally, 8 human cadaver hearts with coronary atherosclerotic plaques were prospectively performed with MRI examination using optimized protocol in order to characterize the coronary atherosclerotic plaques. RESULTS: The SNR and CNR of MR image with temporomandibular coil were the highest of various surface coils. High-resolution and high SNR and CNR for ex vivo coronary artery wall depiction can be achieved using temporomandibular coil with 512 x 512 in matrix. Compared with histopathology, the sensitivity and specificity of MRI for identifying advanced plaques were: type IV-V (lipid, necrosis, fibrosis), 94% and 95%; type VI (hemorrhage), 100% and 98%; type VII (calcification), 91% and 100%; and type VIII (fibrosis without lipid core), 100% and 98%, respectively. CONCLUSION: Temporomandibular coil appears to be dramatically superior to eight-channel head coil and knee coil for ex vivo coronary artery wall imaging, providing higher spatial resolution and improved the SNR. Ex vivo high-resolution MRI has capability to distinguish human coronary atherosclerotic plaque compositions and accurately classify advanced plaques.