1.Application of artificial biomaterials for the treatment of tendon injury
Guangping WANG ; Kaifa ZHANG ; Guifang CHEN
Chinese Journal of Tissue Engineering Research 2009;13(47):9345-9348
OBJECTIVE: To investigate the clinical application of tissue engineering for treating tendon injury.METHODS: A computer-based online search was conducted in Medline and China Academic Journals Database with the key words of "Biological material, Sinew mechanism heals" in both English and Chinese from 1974 to 2009. Relevant books were hand-retrieved.RESULTS: Scholars at home and abroad tried to investigate how to regulate cell proliferation, differentiation, and matrix synthesis by endogenous and exogenous growth factors so as to promote tendon repairing, relieve tendon adhesion, and decrease attenuation of biomechanical intensity. Tendon detect was mainly treated by autologous tendon transplantation,allogeneic tendon transplantation, artificial tendon transplantation, and tissue-engineered tendon transplantation. All those methods had both advantages and disadvantages. However, artificial biomaterial tendon has attracted much attention and it has been used for clinical application. Of course, there are still more problems to be solved, for example, source of tissue-engineered seed cells, immunological reaction of allogeneic tendon cells, specific mechanical intension, preparation and selection of degradable scaffold materials, correlation between cell and scaffold materials, and correlation between cell-material compound and peripheral tissues. With the development of tendon repairing and healing, single drug which was used to prevent tendon adhesion has developed into drug-barrier compound. Additionally, with the development of Chinese herb and molecular biological products, they not only inhibited exogenous healing, but also promote endogenous healing. Meanwhile, simple surgery has also developed into combined therapy.CONCLUSION: Although biomaterials for tendon repairing have achieved breakthrough in some respects, the results need also to be further studied.
2.Neural stem cell transplantation for Alzheimer's disease rats: Efficiency evaluation
Guifang CHEN ; Tiandong LI ; Kaifa ZHANG
Chinese Journal of Tissue Engineering Research 2009;13(45):8987-8991
There are two kinds of treatments on Alzheimer's disease (AD) rat by transplanting neural stem cells (NSCs),i.e.the replacing cell curing and the gene therapy.By replacing method,the AD rats showed signs of recovering to some extent on both histomorphology and behavior after transplanting NSCs into their brains.Transplanting NSCs along with the nerve nutrition factor (NTFs) showed better curative effects than NSCs transplantation alone.However,little is known about the molecular mechanism involving in the development of NSCs in vivo conditions.And the blindness of the treatment hindered the comparison of various affecting factors.The NSCs gene therapy is still in initial studying,with the effects of both cell replacement and gene therapy.This treatment genetically modified NSCs mainly by unitary nutrition fators such as nerve growth factor (NGF),brain-derived neurotrophic factor (BDNF),and glial cell line-derived neurotrophic factor (GDNF).And it was almost known nothing about the exogenous gene expression efficiency,the induce differentiation,the restore of function and security after genetically-modified NSCs transplanted into the AD rat brain.The detecting technology of NSCs transplanting curative effects of the AD rat is unitary at present.And the combined method is the developing trend,such as combining the immunohistochemical method with in vivo-tracking,and combining morphology index with the function index.
3.Subcellular localization prediction of proteins containing fibronectin domains using collocation of amino acid pairs
Liqi LI ; Yuan ZHANG ; Yue ZHOU ; Kaifa WANG
Chinese Journal of Tissue Engineering Research 2011;15(21):3983-3986
BACKGROUND: Proteins containing fibronectin domains play an important role in cell migration, adhesion, growth and differentiation and have been widely applied to a variety of new biological materials. Subcellular localization prediction of proteins containing fibronectin domains can promote protein function research and development of new biomaterials.OBJECTIVE: To realize subcellular localization prediction of proteins containing fibronectin domains. METHODS: A total of 80 human proteins were randomly selected from Uniprot database. The amino acid pairs for each protein were collocated to form 400 dimensional input feature vectors. The feature vectors were then trained and tested using support vector machine and k-nearest neighbor separately. The prediction quality was examined by the jackknife test. RESULTS AND CONCLUSION: The prediction accuracy was 92.5% and 95% for support vector machine and k-nearest neighbor methods respectively. This suggests that support vector machine and k-nearest neighbor methods are of important significance for predicting subcellular localization of proteins containing fibronectin domains and contribute to functional research of such proteins and surface modification of new biomaterials.
4.The activation effect of maize pollen polysaccharides on human thoracic cavity macrophages
Liqin JIN ; Jianxin LU ; Kang YU ; Qian YUAN ; Kejian XIE ; Kaifa WANG ; Yulan ZHANG
Chinese Journal of Pathophysiology 2000;0(08):-
AIM: To study the activation effects of maize pollen polysaccharides(PPM) on human thoracic cavity macrophage (hTM). METHODS: Activities of lactate dehydrogenase(LDH) and acid phosphatase (ACP) in the hTM were detected by automatic biochemical analyzer, and the level of tumor necrosis factor alpha(TNF-?) and interleukin-6(IL-6) in the hTM was analyzed by radioimmunoassay, after hTM were cultured with 0.312,0.625, 1.250, 2.500, 5.000 mg/mL PPM-RPMI 1640 for 24 and 48 hours in vitro. RESULTS: The activities of LDH and ACP increased in the hTM induced by PPM, and the levels of TNF-? and IL-6 in the hTM induced by PPM increased markedly too. And the induced expression effect of TNF-? and IL-6 is associated with the concentration of PPM, and time for PPM inducing. CONCLUSION: PPM can induce cytokines secretion in hTM,and activate hTM in vitro.
5.Genetic Polymorphisms of Glutathione S-transferase M1 and T1 and Evaluation of Oxidative Stress in Patients with Non-small Cell Lung Cancer
Hongyan ZHANG ; Xuwei WU ; Yi XIAO ; Mei CHEN ; Zhidong LI ; Yanli LI ; Kaifa TANG
Journal of China Medical University 2014;(5):432-436
Objective To investigate the genetic polymorphisms of the glutathione S-transferase M1 and T1 genes(GSTM1 and GSTT1),and eval-uate the oxidative damage in patients with non-small lung cancer(N-SCLC). Methods A total of 110 patients with N-SCLC and 100 healthy indi-viduals were recruited in this case-control study. Multiplex polymerase chain reaction(PCR)analysis was used to identify the genotypes. The activi-ty of malondialdehyde(MDA),nitric oxide(NO),and the total antioxidant capacity(T-AOC)were detected by spectroscopic analysis using assay kits. Results The frequencies of the GSTM1,T1,and GSTM1/T1 null genotypes in the patient group were significantly higher than those in control group(OR1=2.071,P1=0.009;OR2=1.900,P2=0.024;OR3=3.258,P3=0.003). The activity of MDA and NO were obviously higher in the pa-tient group compared with the control group(P<0.001),and T-AOC was obviously lower in patient group than those in control group(P<0.001). The activity of MDA,and NO were higher but the T-AOC were lower in patients with GSTM1,T1 and GSTM1/T1 null genotypes than those in pa-tients with GSTM1,T1 and GSTM1/T1 present genotypes(P<0.001). Conclusion Our results suggest that oxidative damage may play a impor-tant role in patients with N-SCLC,and the N-SCLC patients with GSTM1and GSTT1deletion genotypes are more susceptible to oxidative damage.
6.Analysis on the misuse of chi-square test
Chinese Journal of Burns 2024;40(5):482-488
Count data are very common in biomedical research, and such kind of data is often organized in the form of contingency table. For count data, the common research purpose is to test whether two factors are independent, therefore chi-square test is often used for statistical analysis, but it is easy to overlook the applicable conditions of chi-square test and the correction of results under different conditions. In addition, for count data, there are also other research purposes, such as testing whether there is a linear trend between two categorical variables, whether the results are consistent, and so on. Therefore, how to choose appropriate testing methods based on different research purposes is also a problem worth paying attention to in practical applications. In this study, the commonly used statistical methods for various count data are systematically summarized through a series of examples, and the common misuses of the chi-square test are analyzed.