A variety of benign and malignant disorders affecting the trachea can theoretically be treated by simple resection and subsequent end-to-end anastomosis of remained trachea. Unfortunately, it is feasible only when the affected tracheal length does not exceed 50% of the entire length in adults and about 30% in children. Tracheal transplantation may be a treatment option for those patients, but still has many problems to be solved, such as immunological rejection, revascularization, infection and granulation tissue hyperplasia. This review focuses on how to use different methods to inhibit immunological rejection of tracheal transplantation, and current research progress of immunological rejection in tracheal allograft.
ObjectiveTo investigate the biocompatibility and immunogenicity of the tracheal matrix decellularized by sodium perchlorate (NaClO4).MethodsBone marrow mesenchymal stem cells (BMSCs) were divided from 2-month-old New Zealand white rabbits. The trachea of 6-month-old New Zealand white rabbits were trimmed to a length of 1.5 cm and randomly divided into control group (group A1, n=5, just stripped the loose connective tissue outside the trachea) and experimental group (group B1, n=5, decellularized by improved NaClO4 immersion method). The cytotoxicity of the scaffold leaching solution was detected by MTT assay, and the major histocompatibility complex (MHC) expression was detected by immunohistochemical method. The 4th generation of BMSCs were seeded onto the scaffold of 2 groups, and the cell activity around the material was observed by inverted microscope after Giemsa staining at 48 hours, while the cells states on the scaffold were observed at 7 and 14 days after culturing by scanning electron microscope. Another 10 6-month-old New Zealand white rabbits were randomly divided into control group (group A2, n=5) and experimental group (group B2, n=5), which implanted the native trachea and decellularized tracheal matrix into the subcutaneous sac of the back neck, respectively. The serum immunoglobulin IgM and IgG contents were analysed at 5, 10, 15, 20, 25, and 30 days after operation, and HE staining observation was performed at 30 days after operation.ResultsMTT assay showed that the proliferation activity of BMSCs cultured in the leach liquor of group B1 was well, showing no significant difference when compared with group A1 and negative control group with pure culture medium (P>0.05). The immunohistochemical staining showed that the decellularized process could significantly reducing the antigenicity of matrix materials. Giemsa staining showed that BMSCs grew well around the two tracheal matrixs (groups A1 and B1) in vitro. Scanning electron microscope observation showed that the cells were attached to the outer wall of the tracheal material in group A1, which present a flat, round, oval shaped, tightly arranged cells and cluster distribution; and in group B1, the cells formed a single lamellar sheet cover the outer wall of the tracheal material, whose morphology was similar to that in group A1, and the growth trend was better. In vivo experimental results showed that the rejection of group B2 was lower than that of group A2. The contens of IgM and IgG in group A2 were significantly higher than those in group B2 at each time point after operation (P<0.05). HE staining showed no signs of rejection, macrophagocyte, or lymphocyte infiltration occurred, and the collagen fibers maintained their integrity in group B2.ConclusionThe decellularized matrix treated by NaClO4 has a fine biocompatibility, while its immunogenicity decreased, and it is suitable for the scaffold material for constructing of tissue engineered trachea.
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.