1.Advances in DNA recognition receptors
Chinese Journal of Cancer Biotherapy 2010;17(1):99-103
DNA, as the material basis of all living cells, triggers innate immune responses through TLR9 and other cytosolic recognition receptors. In recent years, the research progress of TLR9 is mainly manifested by the following four aspects: (1) the determinants of TLR9 interacting with its ligands; (2) the mechanisms and the importance of TLR9 translocation from the endoplasmic reticulum to the endosome; (3) the roles of the endosomal acidification and maturation, and subsequent TLR9 cleavage in TLR9 signal transduction pathway; and (4) the possible mechanisms by which the organism distinguish self DNA from microbial DNA. Meanwhile, a series of experiments on TLR9 antagonists and TLR9 deficient mice confirmed the presence of TLR9-independent cytosolic DNA sensors. So far, three TLR9-independent DNA sensors have been found, and they are DAI, AIM2, and RNA polymerase Ⅲ.
2.Effect of Benzo (a) pyrene on DNA of Human Embryonic Fibroblast under Inhibition of DNA Repair
Yongjun XU ; Xuetao BAI ; Hongwei ZHANG
Journal of Environment and Health 1989;0(06):-
Objective To study the effect of benzo(a) pyrene on DNA of human embryonic fibroblast under inhibition of DNA repair,and to explore the mechanism of DNA repair involved in the DNA damage induced by xenobiotic chemical carcinogens. Methods DNA damage of human embryonic lung fibroblast (HELF) induced by benzo(a) pyrene was observed when DNA repair was inhibited by treating HELF with arabinosylcytosin(ara-C) to inhibit the activity of polymerase ?/? in the cells. With S9 mixture added as metabolic activation system in vitro,HELF was treated for 2 hours with ara-C at the doses of 0 and 100 ?mol/L combined with-C at the doses of 0,10,20,50 ?mol/L by the 2?4 factor-factorial analysis.Comet assay was used to assess the DNA damage. Results Compared with the control group,the comet rate and Oliver tail moment of groups treated by B(a)P increased significantly (P
3.Air Pollutants-Asthma Triggers and Mechanisms
Qiang WANG ; Xuetao BAI ; Dongqun XU
Journal of Environment and Health 1989;0(06):-
Asthma is a chronic respiratory disease with various etiologic factors.Asthma is believed as a result of interaction between gene variation and environmental factors.Asthma increased rapidly worldwide in recent 40 years, air pollutants are believed to be the important triggers, crossover design and multi-pollutant models were used in the further studies.Although some efforts had been made in the mechanism of asthma triggers, they were limited to the lab studies.Studies in asthma related SNP and its interaction with air pollutants will be a revised method in mechanism researches.Based on epidemiological studies, in vivo and in vitro studies, the biological effects and mechanisms of air pollutants on asthma were discussed and evaluated in this paper.
4.Preparation of carboplatin-loaded albumin microsphere and its properties in vitro
Hao ZHU ; Xuetao JIANG ; Fenghua XU
Chinese Pharmaceutical Journal 1998;(2):91-
To prepare bio-degradable albumin microspheres containing carboplatin. METHODS: Bovin serum albumin microspheres containing carboplatin were prepared by using emulsion-direct heat cross linking techniques. RESULTS: The microsphere was yellow, powdery, with a mean diameter of 58.2 μm. The microphere loaded (11.26±0.48)% carboplatin. The trapping efficiency was (84.5±3.6)%. The pattern of drug releasing from the microspheres in vitro fitted to zero order release plot, with an initial burst in the first 2 hours. The releasing rate can be expressed by the follow equation: Q=21.90+8.50 t (d), r=0.995 8. t50=3 d. Stored at 4 ℃ and 37 ℃ respectively for 3 months, the microspheres did not alter much in shape, size and drug content. CONCLUSIONS: This method is simple, reproducible, having high drug trapping efficiency. The microsphere obtained is stable and release drug at a consistant rate in vitro, leading to a prosperity in clinical use.
5.Comparison of Performances of Three Kinds of Direct Current Power Source in the Application of Electrical Impedance Tomography(EIT)
Jieshi MA ; Xuetao SHI ; Canhua XU ; Meng DAI ; Xiuzhen DONG
Chinese Medical Equipment Journal 2003;0(11):-
Objective To provide the hardware system of EIT with an excellent direct current(DC) power source. Methods The spectrums of the outputs of DC power source and the driving source were analyzed by means of Spectrum Analyzer- E4408B when EIT system was respectively powered by battery, linear power source and switching power source. Based on the numbers and power levels of the spurs of the three power sources and the numbers and power levels of the interferences within the driving source, the influence of the three power sources on the error of measuring was estimated. Meanwhile the EIT system did data acquisition, the overall signal-to-noise-ratio(SNR) of the three power sources at the 18 frequencies were calculated and the influence of the three power sources on the error of measuring was judged. Results With respect to the numbers and power levels of the interferences within the driving source when EIT was powered respectively by the three power sources, the battery output 6 interferences, the highest power of which achieved -78.25 dBm; the linear power source output 6 interferences, the highest power of which achieved -67.11 dBm; the switching power source output 15 interferences, the highest power of which achieved -35.83 dBm. The overall SNRs of the battery at the 18 driving frequencies were higher than that of the linear power source, and the overall SNRs of the linear power source were higher than that of the switching power source. Conclusion The power mode of battery is the best for the hardware of EIT among the three power sources.
6.Comparison of Performances of Ag/AgCl Coating Electrodes and Pulverized Electrodes in Cerebral Application of Electrical Impedance Tomography
Meng DAI ; Xiuzhen DONG ; Fusheng YOU ; Xuetao SHI ; Canhua XU
Chinese Medical Equipment Journal 2004;0(09):-
Objective To compare the performance of novel Ag/AgCl pulverized electrodes with conventional Ag/AgCl coating electrodes in cerebral application of Electrical Impedance Tomography(EIT).Methods Based on the EIT system developed by our group,raw data were measured on a phantom and an adult volunteer,with Ag/AgCl coating electrodes and pulverized electrodes,respectively.The performances of electrode systems were evaluated in contact impedance and two other figures(the high-frequency SNR,HFSNR;the low-frequency SNR,LFSNR).Results Ag/AgCl pulverized electrode plays a better performance in resisting noise and keeping stabilization.Conclusion Ag/AgCl pulverized electrode develops the needs of imaging and monitoring human brains in EIT more availably.
7.Meta-Mesh: metagenomic data analysis system.
Xiaoquan SU ; Baoxing SONG ; Xuetao WANG ; Xinle MA ; Jian XU ; Kang NING
Chinese Journal of Biotechnology 2014;30(1):6-17
With the current accumulation of metagenome data, it is possible to build an integrated platform for processing of rigorously selected metagenomic samples (also referred as "metagenomic communities" here) of interests. Any metagenomic samples could then be searched against this database to find the most similar sample(s). However, on one hand, current databases with a large number of metagenomic samples mostly serve as data repositories but not well annotated database, and only offer few functions for analysis. On the other hand, the few available methods to measure the similarity of metagenomic data could only compare a few pre-defined set of metagenome. It has long been intriguing scientists to effectively calculate similarities between microbial communities in a large repository, to examine how similar these samples are and to find the correlation of the meta-information of these samples. In this work we propose a novel system, Meta-Mesh, which includes a metagenomic database and its companion analysis platform that could systematically and efficiently analyze, compare and search similar metagenomic samples. In the database part, we have collected more than 7 000 high quality and well annotated metagenomic samples from the public domain and in-house facilities. The analysis platform supplies a list of online tools which could accept metagenomic samples, build taxonomical annotations, compare sample in multiple angle, and then search for similar samples against its database by a fast indexing strategy and scoring function. We also used case studies of "database search for identification" and "samples clustering based on similarity matrix" using human-associated habitat samples to demonstrate the performance of Meta-Mesh in metagenomic analysis. Therefore, Meta-Mesh would serve as a database and data analysis system to quickly parse and identify similar
Cluster Analysis
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Computational Biology
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methods
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Databases, Genetic
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Humans
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Metagenome
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Metagenomics
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methods
8.Image registration of a three-dimensional dynamic phantom in four-dimensional cone-beam computed tomography and four-dimensional computed tomography
Chen SU ; Sen BAI ; Guangjun LI ; Yingjie ZHANG ; Renming ZHONG ; Feng XU ; Yanlong LI ; Xuetao WANG
Chinese Journal of Radiation Oncology 2015;(5):581-584
Objective To evaluate the image quality and registration accuracy of a three?dimensional ( 3D ) dynamic phantom in four?dimensional computed tomography ( 4DCT ) and four?dimensional cone?beam computed tomography ( 4DCBCT) . Methods The Computerized Imaging Reference Systems Dynamic Thorax Phantom Model 008A was scanned to get 4DCT and 4DCBCT images. Two balls with different diameters ( ?= 1 cm and ?= 2 cm) were used to simulate tumors with different sizes. The motion mode of the balls was 3D sinusoidal motion at 0?25 Hz ( the amplitudes along the x, y, and z axes were ±1?0 cm, ±0?4 cm, and ±0?2 cm, respectively). Gross target volumes (GTVs) from 10?phase bins, internal gross target volumes (IGTV), and target volumes on maximum intensity projection (MIP) and mean intensity projection (MeanIP) images were contoured and calculated. Target volumes on 4DCT or 4DCBCT images were compared with the static and dynamic volumes of the balls ( VS and VD ) . The matching index ( MI) of target volumes between the 4DCT and 4DCBCT images was analyzed after rigid image registration. Results The GTV in each phase of the image was larger than VS . The difference between the average GTV derived from 10 phases of 4DCT or 4DCBCT images and Vs of the small ball was larger than that of the large ball ( 35?03% vs. 22?66%;32?62% vs. 17?00%) . All the IGTVs and target volumes on MIP images were slightly larger than VD , but target volumes on MeanIP images were smaller than VD . The average MI of 10?phase bins of the small ball was smaller than that of the large ball ( 66?76% vs. 82?21%) . Moreover, MIs of IGTV,MIP, and MeanIP of the small ball were also smaller than those of the large ball ( 77?39% vs. 90?29%;75?90% vs. 89?28%;74?47% vs. 82?74%) . Conclusions In the case of a relatively small tumor volume and a relatively large motion amplitude, 4DCT and 4DCBCT should be used with caution for comparison of image registration.
9.Comparative study between off-pump and on-pump of coronary artery bypass grafting
Xu CAO ; Qiang XIE ; Ming JING ; Meng LI ; Xuetao BAI ; Hongwei JIANG
Chinese Journal of Postgraduates of Medicine 2010;33(2):9-10
Objective To compare the clinical effect of off-pump coronary artery bypass grafting (eft-pump CABG)and on-pump coronary artery bypass grafting(on-pump CABG).Methods The clinical dates of 152 cases with coronary artery bypass grafting(off-pump CABG group 85 cases,on-pump CABG group 67 cases)were received from June 2005 to December 2008,the preoperative dates,postoperative mortality and the rate of complication were compared between two groups.Results The preoperative dates of two groups were no significant difference(P>0.05);2 cases(2.35%)were died in off-pump CABG group and 13 cases(15.29%)had complications in off-pump CABG group;9 cases(13.43%)were died in on-pump CABG group and 25 cases(37.31%)had complications in on-pump CABG group.The mortality and the rate of complication in off-pump CABG group was significantly less than that in on-pump CABG group.it was significant difference(P<0.01).Conclusion Off-pump CABG is safe therapy of mieosurgieal operation.
10.Establishment of Fibroblasts-mediated Interleukin-6 Gene Therapy and Its Immune Regulation
Shen GU ; Xuetao CAO ; Weiping ZHANG ; Yizhi YU ; Zhigong XU ; Sikun YANG
Academic Journal of Second Military Medical University 1981;0(03):-
Interleukin-6 (IL-6) is a pleiotropic cytokine which has antitumor activity. In the present study, a model for fibroblasts-mediated IL-6 gene therapy and its immune regulation are described. Human IL-6 cDNA was inserted into plasmid vector BCMGNeo containing a neomycin resistance gene. BCMGNeo-IL-6 was transferred into NIH3T3 fibroblasts by calcium phosphate coprecipitation method. A fibroblast clone (T6.6) secreting 1L-6 at highest level was selected by G418 resistance selection and limiting dilution. When T6.6 was implanted i.p. into mice, IL-6 could be detected in serum after 12 h. Even after 96 h, serum IL-6 still maintained at high level. Lymphocyte proliferation and IL-2 production could be enhanced significantly after in vivo implantation of T6.6. These results demonstrate that fibroblasts -mediated IL-6 gene therapy could augment immune function efficiently and outline a novel strategy for cancer treatment.