ABSTRACT
Objective To establish a one-step recombinase polymerase amplification (RPA) method for pathogen screening and rapid detection in the field targeting for five hemorrhagic fever related viruses (Zaire ebola virus, Sudan ebola virus, Marburg virus, Lassa virus and Yellow fever virus). Methods The specific nucleic acid (NA) fragments of each virus were selected as target genes by genome sequence analysis, and the primers and probes for RPA assays were designed according to the sequence. A series of diluted template genes were used for RPA detection to determine the sensitivity. The hemorrhagic fever-related viral nucleic acids were used for RPA detection to determine the specificity. The amplification experiments were carried out at different temperature ranging from 37℃ to 42℃ to validate the reaction temperature range. Results The RPA reaction systems of the five hemorrhagic fever viruses could effectively amplify the target genes, the sensitivities were between 1.5×102 and 1.5×103 copies. No cross reactions existed with the other hemorrhagic fever-related viral genes. Meanwhile, RPA assay could effectively amplify the target genes at 37-42℃. Conclusion The isothermal RPA assays of five hemorrhagic fever viruses are established, which may amply target genes fast and react at a wide temperature range, and be potentially useful for in field pathogens detection.
ABSTRACT
Objective To prepare quality control samples for St.Louis encephalitis virus(SLEV)molecular detection by constructing pseudovirus containing target sequences of SLEV.Methods According to the principles of armored RNA technique, the prM gene sequence of SLEV was cloned into the prokaryotic expression vector to generate recombinant plasmid pSE380-MS2-SLEV.Then, recombinant E.coli transformed with the corresponding plasmid was induced with IPTG to produce recombinant pseudovirus particles.The particles were purified by chloroform and further characterized by double enzyme digestion and transmission electron microscopy.The temperature sensitivity experiments and quantitative RT-PCR were performed to validate the potential of these pseudovirus particles as quality control samples.Results PCR amplification and sequencing analysis confirmed that the prM gene sequence of SLEV was cloned into vector pSE380-MS2.Transmission electron microscopy showed that homogenous spherical particles with a diameter of about 25 nm were produced upon IPTG induction.The SLEV genomic RNA within the pseudovirus particles was resistant to DNaseⅠand RNase A digestion, and remained stable for 20 days at 37℃.These samples were validated with quantitative RT-PCR for SLEV.Conclusion The RNase-resistant and stable pseudovirus particles containing prM fragment of SLEV are constructed successfully, which can be used as positive quality control samples for RNA extraction and molecular detection.
ABSTRACT
Objective To construct the pseudovirus containing nucleic acid(NA)fragments of Marburg virus,Zaire Ebola virus,Sudan Ebola virus,Lassa fever virus and Yellow fever virus by using a lentiviral vector system in order to provide a reference standard for the detection of the five viruses.Methods The gene fragments of the above five viruses were synthesized in vitro,connected into a single gene by fusion PCR technique,and cloned into lentiviral vectors with its auxiliary vector.After co-transfecting into 293T cells,the supernatants were collected on 48 h and 72 h post transfection. The naked NA was cleaned from the supernatants using DNase and RNase digestion before pseudotype virus was purified and concentrated.After the NA of the pseudotype virus,were extracted normal PCR and real-time PCR were conducted. Results Sequence analysis showed that the five target genes in vitro synthesis were properly connected and inserted into lentivirus vectors.Using the NA of the pseudotype virus as the template,both normal PCR and real-time PCR could sensitively amplify the target gene with the primers and probes of the above five,viruses respectively.The result indicated that the pseudovirus particles containing the five kinds of hemorrhagic fever virus target genes were successfully packaged. Conclusion The pseudovirus particles containing gene fragments of five viruses are constructed,which can be used as a common reference standard for NA detection.
ABSTRACT
Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.
Subject(s)
Animals , Humans , Arachnid Vectors , Virology , China , Encephalitis Viruses, Tick-Borne , Classification , Genetics , Encephalitis, Tick-Borne , Virology , Genome, Viral , Ixodes , Virology , Molecular Sequence Data , PhylogenyABSTRACT
Objective To investigate the diversity of mosquito-borne viruses in Xinjiang , China, and to identify mosquitos-borne viruses of medical importance rapidly .Methods The virus-derived RNAs in mosquitos captured in wild were screened and confirmed by using Illumina deep sequencing approach and reverse transcription PCR , respectively .The alignment analysis was performed by using gene sequences from GenBank.Results One hundred and forty-four Culex Flavivirus ( CxFV, Flavivirus genus, Flaviviridae) specific sequences were identified .The overlapping reads were assembled into 7 uncontinuous viral genomic contigs.The gaps between the contigs were further filled by RT-PCR products, which resulted in reconstruc-tion of viral genomic 5′and 3′terminus (687 nt and 411 nt).Phylogenetic analysis showed that the newly identified CxFV belonged to America/Asian genotype , which specifically clustered into a clade with other CxFV strains from China mainland ,sharing 98.2%-99.5%homologies in nucleotide sequences and 99.5%in amino acids sequences among them .Conclusion Illumina deep sequencing approach was successfully applied to arthropod-borne virus surveillance .The recently emerged Culex Flavivirus was detected for the first time in Xinjiang, China.
ABSTRACT
Objective To express and purify Japanese encephalitis virus ( JEV) EDⅢprotein and evaluate the possibility of using it as a candidate antigen in JEV diagnostic kit .Methods PCR primers spe-cific for the gene encoding JEV EDⅢprotein were designed and used to amplify the gene fragment by RT-PCR.The cloned gene fragment was then inserted into pET-30a (+) to construct the recombinant expression plasmid.The transformed E.coli BL21 carrying expression plasmid were induced by IPTG to express JEV EDⅢ protein.The expressed JEV EDⅢprotein and a control antigen of tick-borne encephalitis virus protein were deposited in small spots to set up ELISA microarray .The serum samples from patients with Japanese encephalitis and healthy people were detected by Array-ELISA.The results obtained by Array-ELISA were compared with those by using indirect immunofluorescence assay .Results The gene fragment encoding JEV EDⅢprotein was successfully cloned and expressed in E.coli BL21.The recombinant protein could be used in Array-ELISA assay for the detection of serum samples from patients with Japanese encephalitis and healthy subjects .The results were consistent with those by using indirect immunofluorescence assay.Conclusion The recombinant JEV EDⅢprotein can be used as a candidate antigen for the diagnosis of JEV infection .
ABSTRACT
Objective To express and purify the recombinant nucleoprotein fragments of hemor-rhagic fever with renal syndrome ( HFRS) virus and to evaluate their diagnostic efficacy by using array-ELISA technology .Methods The target genes encoding nucleoprotein fragments of HFRS virus were amplified by PCR, and then inserted into prokaryotic expression vectors to construct the recombinant plasmids of pET -32a (+)/Pn and pET-32a(+)/Pc.The plasmids were transformed into E.coli BL21 ( DE3) to induce the ex-pression of nucleoprotein fragments by IPTG and the expressed products were purified by affinity chromatog -raphy using Ni-NTA agarose.The specificity and sensitivity of the recombinant antigens were evaluated by the assay of array-ELISA using commercial colloidal gold assay kit as a comparison .Results The recombi-nant nucleoprotein fragments of HFRS virus were correctly expressed in E.coli and highly purified by affinity chromatography .Array-ELISA showed that 13 of 16 suspected serum samples were positive by using the His-Pn protein as diagnostic antigen , consistency with the commercial colloidal gold assay kit reaching 94%. Conclusion The recombinant His-Pn protein expressed in E.coli cells could be used for specific serodiag-nosis of HFRS virus as its high antigenicity and sensitivity .The array-ELISA is an effective assay for the de-tection of virus at protein level .
ABSTRACT
Objective To identify the infection and the replication of Tick-borne encephalitis virus(TBEV) in human neuroblastoma cells.Methods After being inffected with TBEV,the cell culture supernatant of human neuroblastoma cell line SK-N-SH was collected and assayed at different time points.Byusing real-time RT-PCR and plaque assay to measure the titer of virus in the supernatant,the replication andproliferation of TBEV in human neuroblastoma cell was identified.Meanwhile,the morphological change of SK-N-SH after TBEV infection was also visualized by observation under microscope and immunmquorescenceassay.Results Real-time RT-PCR and plaque assay both demonstrated that TBEV could replicate effectively in SK-N-SH cells,the peak titer could reach 2.92× 107 PFU/ml on 3 days post-inoculation.And significant morphological change occured on infected SK-N-SH cells after 2 days post inoculation.By immunofluorescence assay,the virus particles could be detected and visualized.Conclusion TBEV can replicate andproliferate effcctively and cause significant cell morphological changes in human neuroblastoma cell SK-N-SH,which demonstrated that SK-N-SH could be a suitable cell model for TBEV culture.
ABSTRACT
ObjectiveTo develop an antibody-array system for multiple detection of antibodies against Japanese B encephalitis virus (JEV),Tick-borne encephalitis virus (TBV),Dengue virus ( DENV ),West Nile virus (WNV),Western equine encephalitis virus (WEEV) and East Equine encephalitis virus (EEEV).MethodsRecombined antigens were spotted on array as capture antigens.Specific antibodies were detected by using a sandwich ELISA format.Rabbit antiserum was employed to select and confirm the specificity of antigens and to optimize the conditions of the assay.The detection efficiency of the system was validated by 40 clinical suspected serum samples and compared with the relative ELISA assays.ResultsEleven recombined antigens were selected as diagnostic antigens with high specificity.Better detection could be achieved when scale of antigen concentrations were within 0.125-0.900 mg/ml and the serum dilutions were 1:100-1:1000.When detecting the 26 clinical suspected TBE serum samples,20 were IgG positive (76.9％),and 17 were IgM positive (65.3％) which was 96.1％ and 84.6％ consistent with the relevant ELLSA tests,the 8 clinical suspected JEV serum samples,4 were IgG positive (50.0％),and 5 were IgM positive (62.0％),which was 86.3％ and 90.1％ consistent with the relevant ELLSA tests.As for the 22 DEN serum samples,13 were IgG positive (60％) and 15 were IgM positive (68％) which was 85％ and 93％ consistent with ELISA.The specificity of the assay was 100％ and the sensitivity was higher than the relative ELISAs.ConclusionThe developed antibody-array is highly specific and reliable,which could be used for the detection of antibodies against the 6 arboviruses.
ABSTRACT
Objective To explore the relationship of DVL2 expression and the development of (CCRCC) by comparing the changes of DVL2 mRNA and protein expression in CCRCC specimens and matched normal renal specimens and its clinical significance. Methods DVL2 mRNA expressions in 22 CCRCC tissues, the matched adjacent normal tissues, and 10 CCRCC tissues alone were examined by semiquantitative RT-PCR and fluorescence quantitative PCR (real-time RT-PCR). Meanwhile, the different expression of the CCRCC between TNM Stage Ⅲ + Ⅳ and Stage Ⅰ +Ⅱ was also examined. Furthermore,immunohistochemistry was employed to examine DVL2 protein expression in 22 CCRCC and the matched adjacent normal tissues, and the other 10 CCRCC tissuses without the matched tissues. Results The DVL2 mRNA expression levels in 17 CCRCC tissues were increased by semi-quantitative RT-PCR and by real time RT-PCR compared with that in corresponding adjacent normal tissues, with the difference being significantly different (t = 2.535, P =0.0197). The DVL2 expression of 8 in 13 Ⅲ + ⅣCCRCC was higher than Ⅰ +ⅡCCRCC. Immunohistochemical examination showed that the DVL2 protein was located in cytomembrane and cytoplasm. Moreover, the positive level of DVL2 protein in CCRCC tissues[81.8 % (18/22)]was significantly higher than those in the adjacent tissues. However the expression was not associated with patients' age, gender, TNM stages (Fisher exact frenquently, P >0.05). Conclusion The DVL2 expression in CCRCC is obviously higher than the corresponding normal tissues in the level of mRNA and protein. And the higher DVL2 expression might be closely associated with the development and progression of CCRCC in the level of mRNA, which may be a potential molecular marker of CCRCC development and metastasis mechanism.
ABSTRACT
Objective To evaluate the Flavivirus specific monoclonal antibody(McAb) 2A10 as detective antibody for simultaneously identify tick borne encephalitis virus( TBEV), Japanese encephalitis virus( JEV), dengue ( DEN )-2, DEN-4 and yellow fever virus ( YFV ) by antibody microarray technique.Methods The antibody microarray was developed by spotting TBEV, JEV, DEN-2, DEN-4 and YFV specific McAb on chip as capture antibodies. After incubating with cultured viral supernatants of the above viruses, CY3 labeled detective antibody 2A10 was added to the chips. After reaction, the antibody microarray was scanned and the results were analyzed. By comparing the signal intensities of different spots on chips,the detecting titre and sensitivity of 2A10 for Flavivirus were determined, and the value of 2A10 in detection of Flavivirus was evaluated. Results The hybridization results demonstrated that the titre of 2A10 for Flavi2A10 was specific for Flavivirus and could be used as universal detective antibody for Flavivirus on antibody microarray.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression sequence and distribution characteristics of the protooncogenes c-fos, c-myc and endogenous basic fibroblast growth factor (bFGF) genes in burned tissues, and to explore the possible effects of changes in these genes' functions on wound healing.</p><p><b>METHODS</b>Partial-thickness burns of 30% TBSA were established on backs of Wistar rats. In situ hybridization and histological methods were used to detect expression of c-fos, c-myc and bFGF genes in normal and burned tissue at 3 h, 6 h, 1 d, 3 d, 7 d and 14 d postburn.</p><p><b>RESULTS</b>Although expression of c-fos and c-myc genes and bFGF gene could be found in normal skin, the expression of all three were markedly induced by burn wounds and the expression models in sequence and distribution were quite different. Expression of c-fos gene increased and peaked at 6 h. Signals were mainly localized in both nuclei of dermal fibroblasts and monocytes. The expression of bFGF gene increased at 6 h and peaked at 1 d postburn, and was distributed in the cytoplasm of fibroblasts. C-myc gene peaked 3 d postburn and was also distributed in the cytoplasm of fibroblasts.</p><p><b>CONCLUSIONS</b>These results indicated that thermal injury could induce the expression of c-fos, c-myc and bFGF at gene level, showing phasic control and regional distribution. The phasic expression of these genes suggests that there is an interaction between protooncogenes and bFGF, which may play an important role in wound healing. The different expressions of c-fos and c-myc play an inducing role in regulating bFGF, and in turn affect wound healing.</p>
Subject(s)
Animals , Male , Rats , Burns , Metabolism , Fibroblast Growth Factor 2 , Genetics , Gene Expression Regulation , Genes, fos , Genes, myc , In Situ Hybridization , Rats, Wistar , Time FactorsABSTRACT
<p><b>OBJECTIVE</b>To explore the expression characteristic of fibronectin gene in hypertrophic scars and diabetic ulcer tissues.</p><p><b>METHODS</b>The biopsies from normal skins, hypertrophic scars and diabetic foot ulcers were taken. The technique of quantitative polymerase chain reaction (PCR) was used to evaluate the gene expression of fibronectin in the above biopsies.</p><p><b>RESULTS</b>Fibronectin gene expression was enhanced in hypertophic scars and decreased in diabetic foot ulcers compared with that in normal skins. Quantitative comparison showed about 2-fold increase of fibronectin mRNA level in hypertrophic scars and about 3-fold decrease of fibronectin mRNA level in diabetic ulcers as compared with that in normal skins.</p><p><b>CONCLUSIONS</b>Fibronectin gene expression is influenced by the tissue environment. Different expression and synthesis of fibronectin may cause different outcomes in wound healing.</p>
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Cicatrix, Hypertrophic , Metabolism , Diabetic Foot , Metabolism , Fibronectins , Genetics , Gene Expression , RNA, Messenger , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To investigate the proliferative effect of keratinocyte growth factor (KGF-2) on human adult keratinocytes.</p><p><b>METHODS</b>The standard medium was keratinocyte growth medium without bovine pituitary extract (BPE), hydrocortisone or epidermal growth factor (EGF). Keratinocytes from a 48-year-old subject were cultured and seeded on dishes with standard medium of EGF in cell density of 2 x 10(4)/32 mm(2). After 24 hours, the medium was replaced by the standard medium with 0, 4, 16, 125 and 500 ng/ml KGF-2, respectively. The standard medium with EGF was used as the positive control and the standard medium without EGF or KGF-2 was used as the negative controls. The growth of keratinocytes was monitored by 3-(4,5-dimethythiazol-2-yl)-2,5 dipheyl tetrazolium bromide (MTT) assay and by photographs on days 3, 5 and 7, respectively.</p><p><b>RESULTS</b>KGF-2 in concentrations of 4-500 ng/ml showed a significant proliferative effect on days 5 and 7 as compared with that of the negative controls (P < 0.01). On day 3 the cells were proliferated to 1.5-2.5-fold, on day 5 to 3-5-fold and on day 7 to 3-12-fold in KGF-2 medium as that of the negative controls. The optimal response occurred when the concentration of KGF-2 was 125 ng/ml on day 7. Cell proliferation was also consistently higher in all KGF-2 concentrations as compared with that of the positive controls.</p><p><b>CONCLUSIONS</b>KGF-2 has significant effects on the proliferation of adult keratinocytes, which are more effective than that of EGF. This study supports KGF-2 can improve the healing of chronic wounds in adults in clinic.</p>
Subject(s)
Humans , Middle Aged , Analysis of Variance , Cell Division , Physiology , Cells, Cultured , Culture Media, Conditioned , Epidermal Growth Factor , Pharmacology , Fibroblast Growth Factor 7 , Fibroblast Growth Factors , Pharmacology , Keratinocytes , Physiology , Probability , Reference Values , Sensitivity and SpecificityABSTRACT
<p><b>OBJECTIVE</b>To investigate the characteristics of PCNA expression in hypertrophic scars and chronic ulcers and to discuss its relation to their formation.</p><p><b>METHODS</b>The expressive quantity and sites of PCNA were detected with the immunohistochemical SP method.</p><p><b>RESULTS</b>PCNA was expressed in all samples. The expressive quantity in hypertrophic scars was higher than chronic ulcers(P < 0.01). The expressive sites of all samples were in the nucleus of fibroblasts and capillary endothelial cells.</p><p><b>CONCLUSIONS</b>The expressive quantity of PCNA was more in hypertrophic scars and less n chronic ulcers. The quantitative difference of expression between hypertrophic scars and chronic ulcers may be correlated to their formation.</p>
Subject(s)
Adult , Female , Humans , Male , Cicatrix, Hypertrophic , Metabolism , Pathology , Proliferating Cell Nuclear Antigen , Skin Ulcer , Metabolism , PathologyABSTRACT
<p><b>OBJECTIVE</b>To obtain information about the quality of scars of healed venous leg ulcers compared with intact skin on the opposite leg by using high-frequency ultrasound.</p><p><b>METHODS</b>Twenty-eight patients (16 women, 12 men, aged 31 - 89 years) whose venous ulcers had healed and scars formed were included in this study. The echogenicities of scars were measured with a 20 MHz high-frequency ultrasound Dermascan. The thickness of epidermis and dermis was assessed and the number of low echogenic pixels (LEPs) in the papillary dermis and reticular dermis were counted using image analysis software.</p><p><b>RESULTS</b>The average epidermal thickness of the scars after 1 week to 20 years of healing was significantly increased compared to those of the control (P < 0.01), whereas the average dermal thickness of scars after healing was significantly decreased compared to the control (P < 0.01). The numbers of LEPs and the distributions of LEPs between scars and controls had no statistically significant differences. There were no correlations among scar echogenicities, age of healed venous ulcers, initial ulcer areas, age of venous ulcers or age of patients. In the control skin samples, the young group aged 31 - 69 years had fewer LEPs than did the elderly group aged 70 - 89 years.</p><p><b>CONCLUSION</b>Our study demonstrates that after the healing of venous leg ulcers, there are significant differences in the thickness of the epidermis and dermis, but no significant alterations in water content and distribution in the dermis when compared to the controls.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Age Factors , Cicatrix , Diagnostic Imaging , Skin , Diagnostic Imaging , Time Factors , Ultrasonography , Varicose Ulcer , Diagnostic ImagingABSTRACT
Objective To develop a real-time quantitative PCR(RQ-PCR) assay based on TaqMan technology for rapid detection and quantification of tick-born encephalitis virus (TBEV) RNA. Methods According to all the TBEV genome sequences in GenBank, RQ-PCR primers and probes were designed in the conservative regions of TBEV C gene and NS5 gene. In addition, primers for conventional PCR were designed using E gene as target. The detective system was established and validated by using TBEV MDJ01 strain. In order to examine the specificity of the system, other viruses of flavivirus were assayed with the RQ-PCR simultaneously. The TBEV standard curve was drawn respectively by measuring TCID_ 50 titre and copy number. The sensitivity of RQ-PCR and the conventional PCR assays were compared, and TBEV infected mice model was reproduced for evaluation. Results The sensitivity of RQ-PCR assay was 100copies/reaction or 1 TCID_ 50 , which was 10 fold higher than conventional PCR. The results were all negative when used to detect other flavivirus including the yellow fever virus, dengue virus type 1, 2, 3 and 4, Japanese encephalitis virus, West Nile virus. The coefficient of variability was less than 5% from inter- and intra-assay showing that both the repeatability and stability of the system were good. Conclusion A sensitive, specific and convenient RQ-PCR method has been established, which is valuable for early detection of TBEV.
ABSTRACT
AIM: To explore the localization and expression of transfo rming grow th factor-? 1,2 (TGF-? 1,2 ) and alpha-smooth muscle actin (?- ASMA) in fetal a nd adult skins. METHODS: Skins of 15 cases of fetuses with different gestational ages and 5 cases of adults were taken, embedded with paraffin wax, and sectione d. Immunohistochemistry method and pathological method were used to detect the e xpression intensity and distribution of TGF-? 1,2 and ?-ASMA. RESULTS: Positive immunohistochemical signals of TGF-? 1,2 and ?-A SMA were found in fetal and adult skins. In skins derived from young fet us, the positive signals of these three proteins were very weak. Along with the incr ement in gestational age, the positive cellular rates of TGF-? 1,2 and ?- ASMA were elevated pro gressively. In elder fetal and adult skins, TGF-? 1,2 were mostly distributed i n epidermal cells, endothelial cells and some fibroblasts, while ?-ASMA was mainly located in myofibroblasts and sweat gland epithelial cells. CONCLUSION: The endo genous TGF-? 1,2 might be involved in the cutaneous development at embryoni c stage, in the cutaneous structure maintenance at adult stage, and in the wound healing af ter injury.
ABSTRACT
OBJECTIVE: To explore the expression of mRNA and its protein in burned rats and their effects on burn wound healing. METHODS: A partial-thickness burn of 30% total body surface ar ea was created on the back of 40 Wistar rats. In situ hybridization and immunohi stochemical methods were used to evaluate the location and the amount of the c-fos mRNA and its protein in normal skin and the burned skin, respectively, at 3 h, 6 h, 1 d, 3 d, 7 d and 14 d after burn. RESULTS: Under a light microscope, both the expression of c-fo s mRNA and its protein could be found in the normal skin, but their induction le vels were much higher in the burned skin. The level of fos protein expression reached peak at 3 h after burn while that of c-fos mRNA reached peak at 6 h aft er burn. CONCLUSIONS: The expression of c-fos can be induced by burns. And the peak level expression of c-fos mRNA comes later than that of c-fos p rotein. It indicates that the action of fos protein is induced by post-translat ional modification of pre-existing fos molecules.
ABSTRACT
Objective To detect 10 RNA viruses including Alphavirus in Togoviridae, Flavivirus in Flaviridae, Hantavirus and Nairovirus in Bunyavirudae and SARS-CoV in Coronavirudae by using genechip technique. Methods The universal PCR primers of Alphavirus and Flavivirus and the PCR primers specific for HFRSV in Hantavirus and XJHFV in Nairovirus were designed by DNAStar software. PCR primers specific for SARS-CoV were adopted from WHO website. In addition, all the PCR primers specific for each virus were designed inside the regions of universal primers. These specific primers were utilized for amplification of cDNA probes. The concentration of probes, the hybridization temperature and duration, the formulation of hybridization solution and the washing conditions were optimized. Results The specific hybridization signals could be obtained when the concentration of probes was 0.3?g/?l. Good hybridization signals could be obtained for all the 10 RNA viruses when the hybridization solution contained 20% formamide, and the hybridization reaction was conducted at 60℃ for 1.5 hours. Two or four pathogens could be detected simultaneously when the target nuclear acids were amplified by multiplex PCR. Conclusion The results showed that the virus pathogens could be detected by genechip technique, and the key step was to design suitable primers and probes.