OBJECTIVETo explore the efficacy of optical coherence tomography (OCT) in imaging and quantitatively evaluating early enamel caries and provide experimental evidence for the clinical diagnosis of early caries.

METHODSThe smooth surface of bovine teeth showing early artificial caries and demineralization changes was scanned by an all fiber-based OCT for images and optical profiles, which were compared with images from a polarized light microscope (PLM) and mineral loss from an atomic absorption spectrometer. Data were analyzed by paired-sample t-test and Pearson correlation analysis using SPSS software.

RESULTSThe images of enamel with early caries and demineralization from OCT coincided with those from PLM. The integrated reflectivity loss in the early caries group was significantly lower than that in the demineralized group (P < 0.05), whereas no significant difference in demineralized depth was found between the two groups (P > 0.05). A linear correlation was observed between integrated reflectivity loss and mineral loss (P < 0.05).

CONCLUSIONOCT can be used to nondestructively and accurately image early caries and quantify lesion extent and degree, suggesting the extensive use of this approach in the clinical diagnosis of early caries.

Animals ; Cattle ; Dental Caries ; Dental Enamel ; Tomography, Optical Coherence ; Tooth Demineralization

Objective:To investigate the key mechanism of transforming growth factor-β (TGF-β) inducing the expression of interleukin-17D (IL-17D) in lung cancer-associated fibroblast (CAF) and promoting the recruitment of myeloid-derived suppressor cells (MDSCs).Methods:C57BL/6 mice were established for B16 lung melanoma metastasis model (tumor model group), and control group was set up, 6 mice in each group. Flow cytometry (FACS) was used to detect the lung CAF and the changes of its ability to secrete IL-17D and the proportion of MDSCs in tumor mice. The changes of TGF-β level in lung tumor were examined by ELISA and quantitative real-time PCR (RT-qPCR). Lung fibroblasts were screened by FACS, and the effects of TGF-β on the secretion of IL-17D, C-C motif chemokine ligand (CCL)2 and CCL7 in fibroblasts were detected by RT-PCR. The migration of MDSCs under the condition of TGF-β stimulating fibroblasts was detected by Transwell.Results:The proportion of CAF (CD45 -CD326 -CD31 -) in the tumor model group was higher than that in the control group [(28.02±2.23)% vs. (7.35±2.14)%, t=9.956, P<0.001]. The ability of CAF to secrete IL-17D in the tumor model group was significantly higher than that in the control group [(38.27±2.93)% vs. (19.04±3.16)%, t=5.995, P=0.001]. The proportion of MDSCs in the tumor model group was significantly higher than that in the control group [(12.93±1.27)% vs. (8.21±1.40)%, t=4.804, P=0.009]. Compared with the control group, the protein and transcription levels of TGF-β in lung of the tumor model group were significantly increased [(1 685.07±135.61) ng/L vs. (1 047.98±68.50) ng/L, t=5.051, P=0.002; 2.17±0.03 vs. 1.00±0.05, t=51.237, P<0.001]. In vitro, lung fibroblasts were stimulated with different concentrations of TGF-β (0, 5 and 10 μg/L) for 24 hours, the relative expressions of IL-17D mRNA secreted by stimulated fibroblasts were 0.42±0.01, 0.67±0.01 and 0.84±0.04 respectively, the relative expressions of CCL2 mRNA in each group were 0.89±0.08, 1.08±0.04, 1.19±0.01 and CCL7 were 0.53±0.05, 0.65±0.04, 0.74±0.03 respectively. With the increase of TGF-β concentration, the expression levels of IL-17D, CCL2 and CCL7 in fibroblasts were significantly increased ( F=57.384, P<0.001; F=15.802, P=0.004; F=14.544, P=0.005). In addition, compared with the control group (0 μg/L TGF-β), fibroblasts treated with 10 μg/L TGF-β for 24 hours could promote the migration of MDSCs in spleen of tumor mice [(9.59±0.21)% vs. (2.14±0.24)%, t=6.585, P<0.001]. Conclusion:TGF-β can induce high expression of IL-17D in lung CAF, which is an important factor in promoting the expressions of CCL2 and CCL7 and the migration of MDSCs in tumor microenvironment.

2 mmx3 mm experimental windows were prepared in adamant slippery surfaces of 7 fresh uprooted permanent teeth. The teeth surfaces in the windows area were demineralized to create artificial caries mould of early stage by aciding the experimental teeth surfaces of 0, 12, 24, 48, 72, 96, 120 hours with demineralized liquid (pH 4.5) in vitro. The demineralized changes on the experimental teeth surfaces were detected by dental Optical Coherence Tomography (OCT) system, which were newly developed by our research group recently, and the detecting results were compared with clinical digital photomicrography and scanning electron microscopy on the same tooth sample, to checkout the efficacy and feasibility of dental OCT for early quantification detecting of artificial enamel demineralization in vitro. The dental OCT system can safelydetect early enamel demineralization of micron level and noninvasively obtain fine resolution quantification information both in surfaces view and sectional view; OCT could accurately detect surface demineralization changes on the experimental windows of artificial dental caries as early as after 12 hours aciding treatment, earlier than the visual inspection and clinical digital photomicrography. OCT could obtain both superficial view and sectional view of quantificational demineralization in early enamel caries homeochronously, and had high correlation to the results of ultramicromorphological changes detected by scanning electron microscopy. Dental OCT system developed by our group could accurately detect early artificial dental caries atraumaticly with high sensitivity and safety. Moreover, it can obtain quantification data in micron level without damaging the experimental teeth samples.

Objective To establish a multi-regression workload model based on surgical related factors.Methods The routine surgery workload was measured by the RBRVS development process of Hsiao WC,and multiple regression models were established for the operative factors from the surgical project specifications,pricing regulations and the operative workload.Results Top workload factors of an operation were technical difficulty,surgical classification and time cost.Multiple regression equation R2=0.699.One degree increase of technical difficulty would push up workload by 0.034;one level of operation grade would raise workload by 0.793;and every one hour longer of the operation time would increase workload by 1.025. Conclusions Operations of higher level, technical difficulty and longer time cost should deserve more reimbursement in consideration of both pricing and income distribution.

There are many difficulties in digital medical teaching, including new course content, multiple key and difficult points, wide knowledge coverage, large knowledge structure span, high requirements for teachers, and few shared resources for online teaching during the epidemic. This research aims to give full play to the advantages of our team in the field of digital medicine, and promote the construction of network resources of this course and its extensive development in more universities through the exploratory and research on the course construction and teaching mode of the Digital Medicine MOOC (massive open online course). The questionnaire study found that the satisfaction score of the average satisfaction score of MOOC teaching in terms of students' pre-class preview, quick grasp of knowledge points in class and after-class review reached more than 90 points, and the score of improving students' learning initiative was (88.10±10.87) points. It can be seen that the use of MOOC teaching mode can significantly help students to preview before class, master knowledge points in class and review after class, and improve students' initiative in learning. The research suggests that the production of Digital Medicine MOOC should keep the consistency and individuality of all knowledge points under the framework of digital medical knowledge; teachers should focus on the explanation of basic knowledge points and deepen in further step integrated with frontiers of this field; it’s suggested to make a separate MOOC on frontier knowledge and application explanation, so as to cope with the outdated courseware content caused by the development and update of this subject.

Objective To observe the regulatory effect of olfactory ensheathing cells (OECs) on polarization of M2 macrophages after acute contusion of spinal cords in rats,and explore the mechanism of OECs transplantation in promoting repair of spinal cord injury.Methods The primary OECs were isolated and cultured for transplantation.The T10 spinal cords of SD rats were exposed and impacted by impact stick (10 g) dropping vertically from a height of 25 mm with a NYU-Ⅱ impactor.Twenty-four rats with contusion of spinal cord immediately after injury were randomly divided into DMEM/F12 control group and OECs transplantation group according a random number table.DMEM/F12 culture medium or OECs suspension (3×104/μL,1 μL×3 times) was implanted into the injured spinal cords.At one to 9 weeks after injury,Basso Beattie Bresnahan (BBB) scale was used to evaluate the motor functions in rats.At one week after injury,M2 macrophages and Nogo-A positive cells were labeled by immunofluorescence staining;the expressions of interleukin (IL)-4 and IL-6 were detected by Western blotting.At 9 weeks after injury,the pathological changes of injured spinal cords were observed by HE staining.Results One and 9 weeks after injury,BBB scores in OECs transplantation group were significantly higher than those in control group at each time point after injury (P＜0.05).One week after injury,the number of M2 macrophages in OECs transplantation group was significantly larger than that in control group (3.24％ ±0.56％ vs.0.63％ ±0.21％),and the number of Nogo-A positive cells was significantly smaller and fluorescence intensity was significantly lower in OECs transplantation group than those in control group ([43±24] field vs.([207±88]/field;0.042±0.006 vs.0.062±0.011,P＜0.05);the IL-4 protein level was significantly higher and the IL-6 protein level was significantly lower in OECs transplantation group than those in the control group (0.717±0.152 vs.0.183±0.063;0.550±0.124 vs.1.060±0.209;P＜0.05).Nine weeks after injury,the cytoplasmic cavity area in OECs transplantation group ([1.511±0.581] mm2) was significantly lower than that in control group [2.939±0.823] mm2,P＜0.05).Conclusion OECs transplantation may promote macrophages polarizing to subtype M2,improve the microenvironment of inflammation,reduce Nogo-A secretion,thus promote the structure and spinal cord function recovery.