1.Construction of a new vector for targeted gene disruption in Candida albicans
Chinese Journal of Infectious Diseases 2009;27(2):65-68
Objective To explore the feasibility of using Zeocin resistance as a new positive selection marker for the genetic manipulation of Candida albicans (C.albicans).Methods The susceptibility of C.albicans strain CAI4 to Zeocin was determined using a broth microdilution method in pH range from 6.0 to 8.0.The ZeoR expression cassette was amplified from plasmid pGAPZ-α-A by polymerase chain reaction (PCR).An integrated vector used to knockout AAF1 gene was constructed by gene splicing.Then the C.albicans CAI4 was transformed with this integrated plasmid containing the ZeoR expression cassette using lithium chloride method and the target AAF1 gene was replaced.The recombinant C.albicans was screened and the genome was extracted and amplified by PCR with two pairs of primers,then confirmed using genetic method.Results The C.albicans CAI4 was sensitive to Zeocin in pH range from 6.0 to 8.0.And the concentration of Zeoein(100 mg/L) at pH 7.0 was used to select recombined C.albicans.The recombined integrated vector was confirmed by DNA sequencing.The ZeoR expression cassette was detected using PCR method in recombined C.albicans.The AAF1 gene was replaced by ZeoR gene.Conclusion A new vector for targeted gene disruption in C.albicans is successfully constructed.
2.Effect of conditioned medium with concanavalin A-activated spleen cells supernatant on cultured rabbit corneal endothelial cells
Journal of Xi'an Jiaotong University(Medical Sciences) 1982;0(04):-
Objective To evaluate the effect of conditioned medium made up of ConA-activated spleen cells supernatant on cultured rabbit corneal endothelial cells (RCECs).Methods RCECs were primarily cultured in vitro by revealing descemet membrane and endothelium combining tissues masses.Culture medium was RPMI 1640 with 10% FBS and varied concentrations of conA-activated spleen cells supernatant.Experimental groups were divided by different concentrations of ConA-conditioned supernatant:5%,10%,15%,and 20%.In the control group only RPMI1640 and 10% FBS were used.Methyl thiazolyl tetrazolium colorimetry analysis was used to evaluate the proliferation of RCECs cellular population.The cultured cells were identified by immunohistochemical staining for neuronal specific enolase (NSE).Results The RCECs were cultured successfully.RCECs presented positive expression in cytoplasm with NSE immunohistochemical assay.There were significant differences in the experimental groups compared with the control group (P
3.Discussion on Situation and Future of Traditional Chinese Medical Theory in the Debate of Brain or Heart Governing Mind
Journal of Guangzhou University of Traditional Chinese Medicine 2004;0(05):-
This article aims at discussing the situation and future of traditional Chinese medical theory. By comparing the differences of the concept and knowledge about mind between traditional Chinese medicine (TCM) and western medicine, the debate about the source and destination of "brain governing mind" and "heart governing mind" were analyzed and the meaning of mind was thoroughly explained. It is concluded that in the theory of TCM mind is the essence of life. To develop the theory of TCM, the eoncept of TCM terminology should be understood thoroughly; it should be neither misused nor applied mechanically. Only having a good and correct beginning, can the development of TCM theory and its guidance in clinic be achieved.
4.Study on relationship between efflux pumps and Candida albicans resistance mechanism
Chinese Journal of Infectious Diseases 1997;0(04):-
Objective To investigate whether efflux mechanism is involved in azole resistant Candida albicans strains isolated in China. Methods We compared rhodamine 6G uptake and glucose induced efflux between azole sensitive and azole resistant strains to elucidate resistance to azole due to efflux pump, then measured mRNA level of efflux gene cdr1 and cdr2 by reverse transcriptase polymerase chain reaction (RT PCR). Results Rhodamine 6G moved from extra into the intracellular compartment in both azole resistant and azole sensitive strains quickly when in glucose free incubation condition. However, efflux of rhodanmine 6G was enhanced significantly in azole resistant strains and decreased in azole sensitive strains while adding glucose in the media. The mRNA level of efflux gene cdr1 and cdr2 was higher in clinical azole resistant strains and fluconazole induced resistant strains than strains reverted from resistance to sensitivity. However, all such strains had higher efflux gene expression than azole sensitive strains. Conclusions Efflux mechanism is associated with the resistance to azole in Candida albicans strains isolated in China. Fluconazole can induce efflux pumps expression leading to resistance to azole but the resistance to azoles can be reversed after withdrawing fluconazole.
5.Analysis of ERG11 gene mutations in fluconazole-resistant Candida glabrata strains
Yinzhong SHEN ; Hongzhou LU ; Yongxin ZHANG
Chinese Journal of Infectious Diseases 2010;28(6):331-335
Objective To study the mutations of ERG11 gene which encodes P450 lanosterol 14-α demethylase, and to explore the possible role of ERG11 gene in inducing fluconazole resistance in Candida glabrata. Methods ERG11 genes of 9 fluconazole-resistant Candida glabrata isolates and 10 fluconazole-sensitive Candida glabrata isolates were cloned into pUC57-T vector. The open reading frame of ERG11 gene were sequenced by two directional sequencing using universal primers. All sequences were compared with the published sequence. Results Ten kinds of synonymous point mutation were found. Neither missense mutation nor frame-shifting mutation was found. Among the 10 kinds of synonymous point mutation, 5 were found in both fluconazole-resistant and fluconazolesensitive Candida glabrata isolates, and 3 were only found in fluconazole-resistant isolates, 2 were only found in fluconazole-sensitive ones. The majority of the point mutations were located between 1320-2200 base pair of ERG11 gene. Conclusions There are ERG11 gene polymorphisms in clinical strains of Candida glabrata. ERG11 gene mutations are not found to be involved in the development of fluconazole resistance in Candida glabrata.
6.Pulse Signal Quality Estimation and Filtering Based on Cyclostationary Algorithm.
Aihua ZHANG ; Wenlong HU ; Yongxin CHOU
Chinese Journal of Medical Instrumentation 2015;39(2):83-86
In order to reduce the impact of various noise in pulse signal, the quality estimation and filtering algorithms based on cyclostationarity are proposed to reprocess pulse signal. First, A quality evaluation index of pulse signal which named quality factor is defined by cyclic spectrum to describe the quality variation of the pulse signal affected by noise; Second, a cyclic correlation matched filter (CCMF) is designed to remove noise. The simulation of pulse signal is produced by ourselves and noise signal is provided by MIT-BIH physiological database are used to test the function of proposed method, and then the method is applied to the actual pulse signal. The results show that the quality factor can accurately reflect the quality of the pulse signal and the CCMF can effectively remove noise from pulse signal.
Algorithms
;
Databases, Factual
;
Heart Rate
;
Humans
7.The point mutation of cytochrome P-450 lanosterol 14-? demethylase ERG11 gene in Fluconazole-resistant Candida albicans
Feng LONG ; Yongxin ZHANG ; Hekui LAN
Chinese Journal of Infectious Diseases 1997;0(04):-
Objective To investigate the point mutation of the open reading frame of cytochrome P-450 lanosterol 14-? demethylase gene ERG11. Methods In order to identify such alterations, the DNA was extracted by enzyme lysis methods and the PCR was performed. The PCR products were purified and cloned into PBS vector, then transformed into DH5? and sequenced. Results Twenty nine point mutations were identified in this 15 resistant isolates, most of which were different from susceptible strains. The mutations included 12 missense substitutions: F72L, D81G, D116E, K128T, Y132H, E266D, D294G, S361P, M374V, P386L, H400R, and Q474K, of which 6 had not been described previously (D294G, S361P, M374V, P386L, H400R, and Q474K). The other mutations included a frameshift, and 17 silent mutations. Conclusions The point mutation of resistant isolate is different from that of the susceptible isolate. It is suggested that the drug resistance is related with by the newly found alterations, including D294G, S361P, M374V, P386L, H400R, Q474K, and a frameshift.
8.Determination of Bergenin in Roots and Stems of Ardisia Crenata by HPLC
Weifeng FAN ; Yongxin SHI ; Wen ZHANG
Chinese Journal of Information on Traditional Chinese Medicine 2006;0(01):-
Objective To find out the differences of bergenin content in Ardisia crenata from different regions and its different parts,and suggest its medicinal parts. Methods The bergenin content in different parts of Ardisia crenata was identified by TLC and determined by HPLC. Results The difference of bergenin content in different parts of Ardisia crenata was significant,and that in stems was better than in roots,which in the leaves was the lest. Conclusion The stem was regarded as the available medicinal resources and is worth exploiting.
9.Construction of a genomic regulatory network based on gene expression profile of neonatal hypertrophic cardiomyocytes induced by phenylephrine
Yongxin ZHANG ; Zijian LI ; Jie YAN ; Youyi ZHANG
Chinese Journal of Pathophysiology 2009;25(11):2081-2087
AIM: To construct a genomic regulatory network based on gene expression profiling of hypertrophic cardiomyocytes induced by phenylephrine in neonatal rats. METHODS: Cultured neonatal hypertrophic cardiomyocytes were induced by phenylephedrine. The gene expression profiles of these cells were assessed by using a cDNA microarray, and the microarray data were further analyzed by Pathwaystudio and Agilent Literature Search software. RESULTS: A genes/proteins interaction network was constructed with 450 nodes and 592 edges by analyzing the gene expression in hypertrophic cardiomyocytes and literature mining. The network belongs to scale - free network by topological analysis, and 14 genes/proteins as key nodes, including PTPN11, TRAF6, HSPA8, VIM, RPS6KA3, PTHRP, GRB2 and PI3K, were predicted. Based on GO analysis, the genes/proteins associated with metabolism, signal transduction and cytoskeleton may play important roles in the process of cardiomyocytes hypertrophy induced by phenylephedrine in neonatal rat. CONCLUSION : The genomic regulatory network based on gene expression profiling and literature mining may provide integrated clue to elaborate hypotheses about the evolution of cardiomyocyte hypertrophy.
10.Research on PPG Signal Reconstruction Based on Compressed Sensing.
Aihua ZHANG ; Jiqing OU ; Yongxin CHOU ; Bin YANG
Chinese Journal of Medical Instrumentation 2016;40(1):5-9
In order to improve the storage and transmission efficiency of dynamic photoplethysmography (PPG) signals in the detection process and reduce the redundancy of signals, the modified adaptive matching pursuit (MAMP) algorithm was proposed according to the sparsity of the PPG signal. The proposed algorithm which is based on reconstruction method of sparse adaptive matching pursuit (SAMP), could improve the accuracy of the sparsity estimation of signals by using both variable step size and the double threshold conditions. After experiments on the simulated and the actual PPG signals, the results show that the modified algorithm could estimate the sparsity of signals accurately and quickly, and had good anti-noise performance. Contrasting with SAMP and orthogonal matching pursuit (OMP), the reconstruction speed of the algorithm was faster and the accuracy was high.
Algorithms
;
Humans
;
Image Processing, Computer-Assisted
;
Photoplethysmography