BACKGROUND: Functional tracheal reconstruction remains a surgical challenge due to the lack of satisfactory tracheal substitutes. OBJECTIVE: To review the research hotspot, clinical application, and main obstacles of tissue-engineered trachea METHODS: A computer-based search of PubMed, Medline, and WanFang databases was performed to retrieve relevant articles published from 2004 to 2019 with the search terms “3D printing, tissue-engineered trachea, trachea reconstruction, tracheal replacement” in English and Chinese. A total of 47 literatures were included in the final analysis. RESULTS AND CONCLUSION: At present, the methods of tracheal reconstruction mainly include artificial tracheal transplantation, allotransplantation, autologous tissue transplantation and tissue-engineered tracheal transplantation. Artificial trachea transplants often fail due to rupture, infection and narrowing of the trachea. Allotransplantation requires long-term immunosuppressive therapy, and death is often caused by necrosis and infection because of insufficient angiogenesis after transplantation. Autogenous tissue has limited ability to replicate the structure and function of the trachea and also has surgical trauma. Tissue-engineered trachea can simulate the biological structure and function similar to natural trachea by selecting suitable scaffold materials and implanting seed cells evenly in the scaffold. It seems to be an ideal tracheal substitute. An intact tracheal scaffold was prepared with biodegradable material using 3D printing technology combined with tissue engineering technology and then implanted into the tissue-engineered trachea cultured with mesenchymal stem cells. This provides a new approach to long-segment tracheal defect reconstruction.

Objective Tdentify what techniques were used to relieve Menière′s disorder and benefits the subjects experienced use these self-help techniques in order to guide the clinical practice.Methods The data of Menière′s disorder patients treated in our hospital from January 2011 to December 2013 was collected.After random sampling,the questionnaire(the extensive questionnaire used included an open-ended question asking about the ways that each individual used to relieve their problems associated with Menière′s disorder)results were analysed use the qualitative analysis.Results Lifestyleaccounted for 58% of the self-help tech-nique responses.Among all the subthemes,increasing exercise in general was the most commonly listed method.Conclusion These techniques can be used as self-help methods for other individuals with Menière′s disorder to enhance their adaptation to the condi-tion.At the same time provide the basis for medical workers to guide patients.

Objective To explore the relationship between 5-minute Apgar score and heart rate variability (HRV) in severely asphyxiated neonates. Methods A total of 103 severely asphyxiated neonates with 1-minute Apgar score of 0 to 3 points were selected. They were divided into Group A (>7 points, n=50) and Group B (≤7 points, n=53) based on 5-minute Apgar score. Meanwhile, 40 full-term neonates with 1-and 5-minute Apgar score greater than 7 points were selected as control group. 24-hour dynamic electrocardiogram was performed and HRV was analyzed on the third day after birth in three groups. Results PNN50, rMSSD, SDSD were decreased and SDNN, SDANN were increased in group B as compared with group A and control group (P<0.05). No signiifcant difference of HRV was observed between group A and control group (P>0.05). Conclusions Neonatal asphyxia can cause damage to autonomic nervous system. 5-minute Apgar score and HRV can be joint-ly used as a non-invasive index in autonomic nervous damage and its prognosis in asphyxiated newborns.

Objective To study the expression of CDK4 andβ-Catenin and their relevance in glioma. Methods We used immunohistochemistry to detect the expression of CDK4 andβ-Catenin in forty-five glio-ma tissues and eight normal tissues.According to the classification standard of WHO in 2000 classify and grade the tissues.Results There were significant differences of CDK4 andβ-Catenin expressions between normal tis-sues and glioma tissues(P<0.01).The expression of CDK4 and β-Catenin had positive correlation with the pathological grades of glioma and histological type and increased(P <0.05).Furthermore,the expression of CDK4 was positively correlated with the expression ofβ-Catenin in glioma(r=0.52,P<0.01).Conclusion The increased expression of CDK4 andβ-Catenin may have correlation with malignant change of glioma and oc-curance of glioblastoma,and their combination is expected to become an important indicator in assessing malignant glioma.

Objective To explore central mechanism of metformin(MET)in salt -sensitive hypertensive rats by assessing the effect of metformin on inflammation and oxidative stress in hypothalamic paraventricular nucleus (PVN),sympathetic nerve activity and blood pressure.Methods Eight -week -old male Dahl salt -sensitive rats were divided into 4 groups:the normal -salt diet control group[0.3% NaCl +intracerebroventricular(ICV)artificial cerebrospinal fluid(aCSF)],the normal -salt diet with MET group(0.3% NaCl +ICV MET 25μg/d],the high -salt diet control group (8% NaCl +ICV aCSF),the high -salt diet with MET group (8% NaCl +ICV MET 25μg/d). Mean arterial pressure(MAP)was determined every week by a tail -cuff occlusion.After 6 weeks,all rats were eutha-nized,and blood and brain tissues were collected.Then,the plasma norepinephrine(NE,an indicator of sympathetic activity)was detected by enzyme linked immune sorbent assay(ELISA).The expression levels of interleukin(IL)-1β,IL -10 and NOX -2[a subunit of NAD(P)H oxidase],superoxide dismutase(SOD)in the PVN were detected by immunofluorescence,immunohistochemistry and Western blot methods.Reactive oxygen species(ROS)was detec-ted by dihydroethidium(DHE)staining.Results The MAP level of high -salt diet with metformin group was attenu-ated compared with that of the high -salt diet control group[(129.55 ±6.52)mmHg vs.(154.47 ±6.57)mmHg, F =121.90,P <0.05].The change of plasma NE level of high -salt diet with metformin group was lower compared with that of the high -salt diet control group[(364.57 ±30.73)pg/mL vs.(547.68 ±25.08)pg/mL,F =179.24, P <0.05].The expression levels of IL -1β,IL -6,NOX -2 and ROS were markedly higher in high -salt diet with metformin than those of the high -salt diet control group(F =27.80,21.20,22.48,31.99,all P <0.05),which of IL -10 and SOD was lower(F =17.69,23.69,all P <0.05).Conclusion Metformin may attenuate blood pressure in salt -sensitive hypertensive rats,at least partly via decreasing inflammatory molecules and inhibiting oxidative stress in the PVN,subsequently inhibiting sympathoexcitation.

Objective To discover a novel long noncoding RNA YLL066W-B (referred to as YLB), whose expression can be regulated by a ubiquitin ligases E3, Huwel/Tom1, and further investigate the regulatory effects of YLB on expression of multiple subtelomeric genes. Methods Yeast strains (including Tom1△, YLB-HA, HA-YLB, pYES2-HA-YLB and YLB△) were constructed according to the principle of PCR-based tagging of yeast genes. The effects of Tom1 deletion on gene expression were analyzed by real-time PCR and DNA microarray. The protein levels were detected by Western blot. We further performed quantitative real time-PCR to analyze the inlfuence of YLB on expression of multiple subtelomerical genes.Results We found that deletion of Tom1 in yeast could affect the expression of multiple genes and greatly up-regulated the expression of YLB, which is implicated in cell cycle regulation. By analyzing its nucleotide sequence(171 bp)and detecting protein expression, we speculate that the transcriptional product of YLB is a long noncoding RNA (lncRNA). Although YLB is not homologous to any protein-encoding sequences by NCBI blast, it is homologous to the upstream or downstream regions of the open reading frame of several subtelomerically-encoded genes, including those from pau family and DNA helicase Yrf family. Thus, it is possible that YLB is involved in the regulation of these subtelomerically-encoded genes. Accordingly, deletion of YLB markedly up-regulated the mRNA levels of Yrf1-4, pau4 and pau22, whereas over-expression of YLB greatly down-regulated their expression.Conclusion We have discovered the novel lncRNA YLB. The expression of YLB could be negatively regulated by Tom1, and YLB could regulate the expression of multiple subtelomeric genes.

Cation exchange (CX) reaction for the non-fluorescent ZnS nanocrystal clusters (NCCs) can be used to detect trace biomolecules . Nano clusters synthetized by hydrothermal synthesis are porous. So they can quickly release large amounts of Zn2+ from through cation exchange ( CX) reaction and nano cluster, generate fluorescent signal under the action of zinc reagent to detect fluorescence. The relationship between the release efficiency, target binding force of Zn2+ and its average diamete was investigated when the average diameter was 44 nm, 86 nm and 144 nm in this experiment. Results showed that the smallest nano cluster exhibited the highest cation exchange efficiency, and 71 percent of Zn2+ closed could be released by microwave radiation within 2 min. When the sandwich method of NCCs of 44-nm was used to detect immunoglobulin E (IgE) in a sandwich assay, the limit of detection (LOD) was 5 ng / L, which was 1000 times lower than that of ELISA. It turns out that CX for the ZnS NCCs is superior to the conventional signaling strategies in its high amplification efficiency, robustness, and biocompatibility.

Objectives To evaluate the clinical value of heart rate variability (HRV) analysis in school-age healthy chil-dren with functional ST-T changes in electrocardiogram (ECG). Methods In 143 school-age children (50 cases of functional ST-T changes, 43 cases of myocarditis children with ST-T change, 50 cases of healthy controls without ST-T changes), HRV time domain value was measured in three groups with 24 dynamic electrocardiogram. Results Compared with healthy controls, PNN50, rMSSD and SDSD were decreased while the heart rate, SDNN and SDANN were increased in children with functional ST-T changes (P all<0.05). Meanwhile, compared with children with functional ST-T changes and healthy controls, the heart rate was increased while PNN50, rMSSD, SDSD, SDNN and SDANN were decreased in the myocarditis children with ST-T change (P<0.05). Conclusions The autonomic nervous system of school-age children is not stable. The functional ST-T changes are related with the imbalance between sympathetic and vagus nerve activities. HRV analysis has important diagnostic signifi-cance in the functional ST-T changes.

Objective To analyze the effect of custom abutment and computer aided design and computer aided manufacturing(CAD/CAM) provisional crown on gingival shaping around the implant,and to research the main effect of the custom abutment in the formation of gingival.Methods According to the wishes of patients,fifteen patients were divided into two groups.Gingival molding used CAD/CAM in the observation group(n=7) to design and make custom abutment and provisional crown.The control group(n=8) used the prefabricated abutment and the hand-made self-curing resin temporary crown.Immediately after inserting of final insertion and three months later,pink esthetic score(PES) was calculated in both two groups.Results The labial gingiva curve of the observation group was (1.93±0.27)points,which was higher than (1.56±0.51)points of the control group,there was significant difference between the two groups(t=2.496,P<0.05).After permanent repair of 3 months,the PES scores of the two groups[the observation group (8.71±0.95)points,the control group(8.25±1.04)points]were higher than those of permanent repair day[the observation group (8.29±1.25)points,the control group(7.25±1.04)points],there were statistically significant differences in the total score of PES and permanent repair group permanent repair after 3 months of the day(t=4.290,P<0.05),there was no significant difference between the experimental group(P>0.05).The PES score of the observation group was (8.50±1.09)points,which was higher than (7.75±1.13)points of the control group,but the difference was not statistically significant(P>0.05).Conclusion The effect of the custom abutment on curvature of facial mucosa is significant.The combination of custom abutment and digital provisional crown can achieve better soft tissue stability and ideal aesthetic effect in a short time.

Objective To investigate the anticancer effects and detailed mechanisms of Saikosaponin D (SSD) in human hepatoma HepG2 cells. Methods Cell proliferation and apoptosis were tested by MTT assay and Annexin-V/PI assay respectively. The expressions of CCAAT enhancer binding protein β(C/EBPβ) and p53 were detected by RT-PCR and Western blotting. Results SSD inhibited cell proliferation in a dose-dependent manner and induced apoptosis at the concentration of 5.0mg/L. SSD significantly increased the mRNA and protein levels of C/EBPβ and p53 in a dose-dependent manner. Conclusion SSD exerts its anticancer effect by inhibiting cell proliferation and inducing apoptosis partly through C/EBPβ-p53 signal pathway in HepG2 cells.