There is a high incidence of esophageal cancer(EC) in China.The survival and prognosis of EC is unoptimistic due to the lack of efficient early diagnostic markers.There is an urgent demand of novel biomarkers with more stability,sensitivity and specificity.miRNAs are a class of small non-coding single stranded RNAs consisting of 21-23 nucleotides,which are involved in the pathological and physiological process of life activities.miRNAs are stable not only in tumor tissues,but also in serum/plasma.There are significant differences in the expression patterns of circulating miRNAs between two main types of EC.They are closely related to the occurrence and progression of EC,which make circulating miRNAs a novel kind of biomarkers for differential diagnosis,early supervision of esophageal cancer,and prognosis.

Tissue engineering can regenerate damaged tissues and restore the biological functions by cell or tissue reconstruction,and is becoming a promising method for trachea replacement.Seed cells,cell growth factors and tracheal scaffolds are the three major elements of tissue engineering trachea,as a result researchers have paid a lot of attention to find ideal seed cells.Mesenchymal stem cells (MSCs) are a kind of stem cells with high self-renewal ability and muhi-directional differentiation potential.MSCs are widely distributed in bone marrow,umbilical cord,adipose tissue,myocardial tissue,brain,muscle and skin,and can differentiate into a variety of cells,including osteocytes,chondrocytes,adipocytes and neurocytes.MSCs have the characteristics of high proliferation ability,wide differentiation range and immunomodulatory function,which can be used to repair damaged tissue.These advantages make the MSCs an ideal candidate of seed cells for tissue engineering trachea.This review mainly summarized the application of MSCs in tissue engineering trachea.

Objective To prepare 3D printed tracheal graft and investigate its cellular biocompatibility and biomechanical properties.Methods Bone marrow was isolated from tibial plateau of young New Zealand white rabbit,and bone mesenchymal stem cells (BMSCs) were obtained by whole bone marrow culture method and adherent purification method.Biomechanical test was performed for 3D printed trachea graft.After co-cultured of 3D printed trachea graft and BMSCs,cell morphology was observed and the proliferation index of the cells on 3D printed trachea graft was quantified using sulforhodamine B (SRB) assay.Results 3D printed trachea graft showed excellent biomechanical properties.Cell morphology was normal and cells grew well after co-culture with 3D printed trachea graft.The SRB assay indicated good proliferation of BMSCs on 3D printed trachea graft.Conclusions 3D printed trachea graft shows favorable cellular biocompatibility and biomechanical properties,and therefore can be used as a scaffold material for tissue-engineered trachea.

In recent years,the detection rate of early lung cancer with microscopic lesions such as ground-glass nodules and sub-centimeter nodules (≤ 1 cm) has been significantly higher.For such lesions,early surgical intervention can effectively prolong the survival time of patients.But in the actual operation of these small lesions difficult to detect,which brought great difficulties to surgery.At present,clinically for such small lesions,usually in the preoperative CT-guided puncture positioning based on the implementation of surgical resection.This method of location there are trauma,complications and other shortcomings,so how to more precise positioning and labeling of lung lesions is a clinical problem to be solved urgently.In this paper,the localization and localization of lung lesions in recent years are reviewed,and the advantages and disadvantages of various methods and materials are summarized and analyzed.

The morbidity and mortality of lung cancer were the highest in malignant tumors. In recent years, with the update of clinical assistant examination technology and the popularization of physical examination, especially the development of CT examination, more and more lung cancer in early stage are found in the form of pulmonary nodules. Surgery treatment should be considering as the first choice for early lung cancer. At present, various 3D technologies have been widely used in the field of medicine, leading the thoracic surgery to the direction of minimal invasion and precision. This review focuses on the current application of 3D technology in the perioperative period of early lung cancer.

BACKGROUND:For the replacement treatment of long-segment tracheal defects,although tissue engineering research has made some progress in recent years,it is still not perfect,and one of the biggest difficulties is that the hemodynamic reconstruction of the tracheal replacement cannot be achieved rapidly. OBJECTIVE:To preliminarily explore the potential of polycaprolactone scaffolds modified with exosome-loaded hydrogels to construct a rapidly vascularized tracheal substitute. METHODS:Exosomes were extracted from bone marrow mesenchymal stem cells of SD rats.After preparation of hyaluronic acid methacrylate solution,the exosome solution was mixed with hyaluronic acid methacrylate solution at a volume ratio of 1:1.Hyaluronic acid methacrylate hydrogels loaded with exosomes were prepared under ultraviolet irradiation for 5 minutes.The degradation of exosome-unloaded hydrogels and the controlled release of exosome-loaded hydrogels were detected.Polycaprolactone scaffolds were prepared by 3D printing.The pure hyaluronic acid methacrylate solution and the exosome-loaded hyaluronic acid methacrylate solution were respectively added to the surface of the scaffold.Hydrogel-modified scaffolds and exosome-modified scaffolds were obtained after ultraviolet irradiation.Thirty SD rats were randomly divided into three groups with 10 rats in each group and subcutaneously implanted with simple scaffolds,hydrogel-modified scaffolds and exosome-modified scaffolds,respectively.At 30 days after surgery,the scaffolds and surrounding tissues of each group were removed.Neovascularization was observed by hematoxylin-eosin staining and Masson staining and the expression of CD31 was detected by immunofluorescence. RESULTS AND CONCLUSION:(1)As time went by,the hydrogel degraded gradually,and the exosomes enclosed in the hydrogel were gradually released,which could be sustained for more than 30 days.The exosome release rate was faster than the degradation rate of the hydrogel itself,and nearly 20%of the exosomes were still not released after 30 days of soaking.(2)Under a scanning electron microscope,the surface of the simple polycaprolactone scaffold was rough.After hydrogel modification,a layer of gel was covered between the pores of the scaffold,and the scaffold surface became smooth and dense.(3)After 30 days of subcutaneous embedding,hematoxylin-eosin staining and Masson staining showed that more neovascularization was observed inside the scaffolds of the exosome-modified scaffold group compared with the hydrogel-modified scaffold group.The hydrogels on the scaffolds of the two groups were not completely degraded.Immunofluorescence staining showed that CD31 expression in the exosome-modified scaffold group was higher than that in the hydrogel-modified scaffold group(P<0.000 1).(4)These results indicate that hyaluronic acid methacrylate hydrogels can be used as controlled-release carriers for exosomes.The 3D-printed polycaprolactone scaffold modified by hyaluronic acid methacrylate hydrogel loaded with exosomes has good biocompatibility and has the potential to promote the formation of neovascularization.

Objective:To establish a dental fluorosis model of SD rats with various degrees, to observe the microstructures of enamel samples under scanning electron microscope and to clarify the changes of enamel microstructures with various degrees of dental fluorosis, so as to provide clinical reference for the treatment of patients with moderate and severe dental fluorosis.Methods:Thirty male SD rats (6 weeks of age) were randomly divided into 3 groups with 10 rats in each group. The control group was fed with deionized water without fluoride, the low fluoride group was fed with 50 mg/L NaF deionized water and the high fluoride group was fed with 100 mg/L NaF deionized water in order to establish the dental fluorosis model of rats. After feeding for 6 weeks, the rats were sacrificed and the mandibular incisor teeth were collected and recorded. The surface and sagittal plane of each tooth were observed by scanning electron microscopy and the enamel thickness was measured.Results:In the control group, the enamel color was brown yellow. Enamel color discoloration occurred both in low-fluoride group and high-fluoride group. The enamel color in low-fluoride group was mostly yellow and white striped while in high-fluoride group was mostly chalky white. Under electronic microscope, the enamel rods were alternately arranged and their structure was clear and plump in the control group. The enamel rods of moderate fluorosis were arranged in a straight orientation like tips of bamboo shoots. The enamel rods of severe fluorosis, however, became thinner and the tips of rods were broken. In the control group, sagittal images of enamel turned out to be a dense outer structure with clear boundaries among the inner. The structure of the middle layer was reticulated showing a clear boundary with middle and outer layers. The structure of enamel rods in the inner layers was arranged vertically and horizontally. In the moderate fluorosis group, the outer layer of the enamel became thinner and the middle layer disappeared although the boundary between the outer and middle layers was still clear. In the inner layer, the vertically arranged enamel rods seemed still clear, however the horizontal enamel rods disappeared. In the severe fluorosis group, the outer layer could not be traced. The middle layer was exposed to the air and the inner enamel rods contracted. The inner layers of the enamel had gradually become thinner with the development of the dental fluorosis. The thicknesses of inner layers in control, moderate and the severe groups were (180.71 ±7.01), (157.10 ±11.04) and (121.10 ±12.56) μm respectively. As for the thicknesses of the full layers in the above mentioned three groups, the same trend was observed. The thicknesses, in order of the severity of dental fluorosis, were (241.54 ±7.76), (207.42 ±14.36) and (143.79 ±14.60) μm. Conclusions:With the development of dental fluorosis, the outer enamel layers became thinner or disappeared and the inner enamel layers became thinner or lost its normal structure as well. It is highly recommended that the resin penetration could be used for the proper treatment of moderate and severe dental fluorosis and the strong bleaching and the micro-grinding should be used cautiously.

Objective To prepare 3D printed porous tracheal graft fabricated by PCL and to select the appropriate pore size and surface modification techniques,in order to explore its effect on cell behavior.Methods The PCL porous tracheal graft was prepared by 3D printing technology and biomechanical properties of the graft were measured by means of longitudinal tension,radial compression and three-point bending test.The porous grafts were surface-modified through hydrolysis,amination and nanocrystallization treatment and then characterized by energy dispersive spectroscopy(EDS).The effect of different pore sizes and surface modifications on the cell proliferation behavior was evaluated by CCK-8 and scanning electron microscopy (SEM).Results The 3 D printed porous tracheal graft had similar morphology with the native tracheas(P ＞ 0.05) and better biomechanical properties(P ＜0.05).It was more suitable for cell adhesion and proliferation when the pore size is 200 μm (P ＜ 0.05).Compared to hydrolysis and amination,nanocrystallization treatment successfully improved the cytotropism of the 3D printed tracheal graft(P ＜ 0.05).Conclusion 3 D printed porous tracheal graft shows favorable biomechanical properties.The appropriate pore size of the 3D printed porous tracheal graft is 200 μm and the appropriate surface modification techniques is nanocrystallization.

Objective: To establish an experimental model of Turner′s tooth caused by trauma in SD rats and observe its surface by scanning electronic microscopes(SEM) and energy dispersive spectrometry(EDS) was performed. Methods: 40 SD rats aged one day were randomly divided into four groups(n=10). The control group did nothing, The experimental group was exerted different perpendicular forces(per 5 mm2) on the mandibular anterior alveolar process, which was divided into 5 N force group, 10 N force group and 15 N force group. The SD rats were killed at 30 days old to observe the enamel development of their mandibular central incisors. Meanwhile, SEM and EDS were used to observe normal enamel area and enamel hypoplasia area. Results: The control group: all teeth erupted; all enamels developed well. 5 N force group: all teeth erupted; the occurrence rate of enamel hypoplasia was 10%(2 teeth had enamel discoloration). 10 N force group: 1 tooth unerupted; the occurrence rate of enamel hypoplasia was 80%(12 teeth had enamel discoloration and 4 had enamel defects). 15 N force group: 7 teeth unerupted, the occurrence rate of enamel hypoplasia was 60%(3 teeth had enamel discoloration and 9 had enamel defects). There was a statistic difference in the number of unerupted teeth between group 10 N force group and 15 N force group(P<0.05). Under SEM, cracks and rough appeared on the surface of enamel. EDS showed that the Ca and P content in enamel hypoplasia was lower than that in the normal enamel area(P<0.05). Conclusion Tooth trauma can lead to enamel hypoplasia and unerupted teeth. The force of 10 N per 5 mm2is better to establish an experimental model of Turner′s tooth caused by trauma in SD rats. The surface enamel of Turner′s tooth caused by trauma is rough, uneven and the content of calcium and phosphorus decreases.

Objective    To investigate the prevalence and related factors of primary palmar hyperhidrosis in adolescents in Yangzhou. Methods    On-site questionnaire survey was performed on students selected by cluster random sampling from the two colleges and two high or middle schools, with each class as a unit. Data were collected through the questionnaire to make the diagnosis and severity grading. Results    A total of 3 487 copies of the questionnaire were distributed in the survey and 3 299 were finished, among which 3 083 were effective with an effective rate of 88.41%. Among them, 1 358 respondents were males and 1 725 were females; 933 were middle school students, 809 high school students, and the remaining 1 341 college students. According to the diagnostic criteria, 104 respondents were diagnosed with palmar hyperhidrosis with an overall prevalence of 3.37%. There were 60 (4.41%) males and 44 (2.55%) females. Although the prevalence of palmar hyperhidrosis in males was higher than that of females (χ2=8.130，P<0.05), severe palmar hyperhidrosis was more often to be observed in females than in males, and females were also more likely to have hyperhidrosis in other parts of the body. In addition, the age of the first onset of the disease was mainly 10 to 20 years old and 36.54% of the patients had a family history. Conclusion    The prevalence of palmar hyperhidrosis in adolescents in Yangzhou was 3.37%, and there is a significant difference in the gender. The palmar hyperhidros is often accompanied by hyperhidrosis symptoms of other parts of body, and the disease shows an obvious genetic predisposition.