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1.
Artigo em Inglês | MEDLINE | ID: mdl-30431406

RESUMO

Tick-borne encephalitis virus (TBEV) can cause fever, headache, neurological disorders, and/or peripheral flaccid paralysis; therefore, it is a major threat to public health. A rapid, sensitive, and simple method for detecting anti-TBEV antibodies is needed urgently to determine infection and for vaccine evaluation. Here, a luciferase-based immunocomplex assay system (Luc-IC) was developed to detect TBEV antibodies. The system is based on a reporter Nano luciferase (NLuc) that is co-expressed as a fusion protein with viral envelope domain III (ED3) in COS7 cells. The cell supernatant was used directly to detect antigen without the need for a purification step. This simple procedure effectively improved the sensitivity of the assay. Sera from 50 patients with an acute tick-borne encephalitis infection were tested to determine the sensitivity of the NLuc-IC assay. Furthermore, 62 sera from individuals infected with Japanese encephalitis virus, West Nile virus, yellow fever virus, dengue virus, or Zika virus were also tested to determine specificity. The results demonstrated that the assay was 100% sensitive and 100% specific for TBEV antibodies. Thus, this very simple NLuc-IC assay is potentially useful for rapid and accurate diagnosis of TBEV infection in both humans and animals.

2.
J Gen Virol ; 96(9): 2522-30, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25998916

RESUMO

Live-attenuated influenza vaccines (LAIVs) are now available for the prevention of influenza, with LAIV strains generally derived from serial passage in cultures or by reverse genetics (RG). The receptor-binding domain (RBD) in haemagglutinin (HA) of influenza virus is responsible for viral binding to the avian-type 2,3-α-linked or human-type 2,6-α-linked sialic acid receptor; however, the virulence determinants in the RBD of H5N1 virus remain largely unknown. In the present study, serial passage of H5N1 virus A/Vietnam/1194/2004 in Madin-Darby canine kidney cells resulted in the generation of adapted variants with large-plaque morphology, and genomic sequencing of selected variants revealed two specific amino acid substitutions (K193E and G225E) in the RBD. RG was used to generate H5N1 viruses containing either single or double substitutions in HA. The RG virus containing K193E and G225E mutations (rVN-K193E/G225E) demonstrated large-plaque morphology, enhanced replication and genetic stability after serial passage, without changing the receptor-binding preference. Importantly, in vivo virulence assessment demonstrated that rVN-K193E/G225E was significantly attenuated in mice. Microneutralization and haemagglutination inhibition assays demonstrated that immunization with rVN-K193E/G225E efficiently induced a robust antibody response against WT H5N1 virus in mice. Taken together, our experiments demonstrated that K193E and G225E mutations synergistically attenuated H5N1 virus without enhancing the receptor-binding avidity, and that the RG virus rVN-K193E/G225E represents a potential H5N1 LAIV strategy that deserves further development. These findings identify the RBD as a novel attenuation target for live vaccine development and highlight the complexity of RBD interactions.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/genética , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Influenza Humana/virologia , Mutação de Sentido Incorreto , Animais , Anticorpos Antivirais , Cães , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Imunização , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/química , Influenza Humana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Terciária de Proteína , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/química , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacinas Virais
3.
Arch Virol ; 158(10): 2185-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23605588

RESUMO

Amur virus (AMRV) is a member of the genus Hantavirus in the family Bunyaviridae. In this study, we determined for the first time the complete genome sequence of the AMRV H8205 strain, which was isolated from a patient with hemorrhagic fever with renal syndrome (HFRS) in China. The complete nucleotide sequence of the S segment of AMRV H8205 is 1699 nt long, with a 5' noncoding region (5'NC) of 36 nt, followed by a coding sequence of 1290 nt and a 3'NC of 373 nt. The complete sequence of the M segment is 3615 nt long, with a 5'NC of 40 nt, followed by a coding sequence of 3408 nt and a 3'NC of 167 nt. The complete sequence of the L segment is 6536 nt long, with a 5'NC of 37 nt, followed by a coding sequence of 6453 nt and a 3'NC of 40 nt. The major open reading frame (ORF) of each of the three segments (S, nt 37-1326; M, nt 41-3445; L, nt 38-6490) has a coding capacity of 430 aa, 1135 aa, 2151 aa, respectively. Phylogenetic analysis of the nucleotide sequences using the NJ method indicated that H8205 virus, together with the Amur strains isolated from Far-Eastern Russia and Korea, forms a well-supported lineage. Our results will provide insights into the genetic diversity of hantaviruses (HNTV).


Assuntos
Bunyaviridae/classificação , Bunyaviridae/genética , Genoma Viral , Animais , Cercopithecus aethiops , China , Dados de Sequência Molecular , Filogenia , Células Vero
4.
Virus Genes ; 46(1): 165-6, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23090832

RESUMO

In this study, the complete genomic nucleotide sequence of Chikungunya virus (CHIKV) strain S27 African prototype was determined and three 21 nucleotides repeated sequence elements (RSEs) at positions 11398-11418, 11533-11553, and 11620-11640 in the 3' untranslated region (3'UTR) were confirmed. In addition, the 3'UTRs of all CHIKV strains deposited in GenBank were analyzed. The results displayed that the majority of the CHIKV strains consisted of the three 21 nucleotides RSEs in the 3'UTRs, and the third RSE was the most conservative. The conservation of the three RSEs of 21 nucleotides within the 3'UTR of CHIKV genome may play an important role on the virus replication cycle.


Assuntos
Regiões 3' não Traduzidas , Vírus Chikungunya/genética , Genoma Viral , RNA Viral/genética , Sequências Repetitivas de Ácido Nucleico , Análise de Sequência de DNA , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/virologia , Febre de Chikungunya , Vírus Chikungunya/isolamento & purificação , Surtos de Doenças , Humanos , Dados de Sequência Molecular , Tanzânia/epidemiologia
5.
Beijing Da Xue Xue Bao Yi Xue Ban ; 44(3): 339-46, 2012 Jun 18.
Artigo em Chinês | MEDLINE | ID: mdl-22692300

RESUMO

OBJECTIVE: To explore the correlation between feeding index and growth development status of infants from two counties of western China by applying the method of multiple correspondence analysis. METHODS: Two sample counties were randomly selected from the ones that satisfied the research conditions in Shaanxi province and Chongqing in western China. In the study, 472 premature/low birth weight infants (PLBW) and 461 normal term infants (NT) of 6-36 months from the two counties were investigated from September 2010 to November 2010. The SPSS 19.0 software was applied to analyze the data using general statistical analysis and multiple correspondence analysis. RESULTS: In the two counties of western China, the proportion of infants with feeding index at the medium level was the highest, which was between 50% and 60%. In the PLBW group and the NT group, the proportion of low level of feeding index among 6-9 month-old infants was the highest, and the proportion was 33.3% for the PLBW group and 29.4% for the NT group. For both the PLBW group and the NT group, the distribution of feeding index among the different age groups showed significant difference (P<0.05).Among the infants with low level of feeding index, the growth development of the PLBW lay behind that of the NT. We could see a catching-up trend of the PLBW with medium or good level of feeding index, but their growth development index was still at a lower level than that of the NT with the same level of feeding condition. Through multiple correspondence analyses, the outcomes of PLBW corresponded and strongly correlated with low level of feeding index, low level of growth development index, mother's low education degree and low annual family income. And the outcomes of NT corresponded and strongly correlated with medium/good level of feeding index, medium level of growth development status, mother's medium/high education degree and medium/high level of annual family income. CONCLUSION: There are good correspondence correlations at different hierarchical levels of the infants' group, feeding index, growth development index and family factors in the two counties of western China. Multiple correspondence analysis could directly reveal the correlation among several variables, which is a suitable method for categorical data. The result can be illustrated directly through a two-dimensional graph and could provide the suggestion of feeding practice for different infants in western rural China.


Assuntos
Desenvolvimento Infantil , Análise Fatorial , Métodos de Alimentação/estatística & dados numéricos , Pré-Escolar , China , Feminino , Humanos , Renda , Lactente , Masculino , População Rural , Amostragem , Fatores Socioeconômicos , Inquéritos e Questionários
6.
Virol J ; 7: 113, 2010 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-20515509

RESUMO

A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009) influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose) for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same as that of each single-target RT-PCR for pandemic H1N1 and even more sensitive for H5N1 with the same primers and probes. No cross reactivity of detecting other subtype influenza viruses or respiratory tract viruses was observed. Two hundred and thirty-six clinical specimens were tested by comparing with single real-time RT-PCR and result from the duplex assay was 100% consistent with the results of single real-time RT-PCR and sequence analysis.


Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Humana/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Linhagem Celular , Primers do DNA/genética , Cães , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Virus da Influenza A Subtipo H5N1/genética , Influenza Humana/epidemiologia , Camundongos
7.
Zhonghua Wai Ke Za Zhi ; 47(4): 279-81, 2009 Feb 15.
Artigo em Chinês | MEDLINE | ID: mdl-19570391

RESUMO

OBJECTIVE: To discuss the feasibility of the operation of minimal invasive with gallbladder preserved via choledochoscopy. METHODS: From February 1992 to June 2006, there were 760 patients who underwent cholecystolithiasis treated with the minimal invasive operation with gallbladder preserved via choledochoscopy, among which there were 428 males and 332 females, aged from 18 to 81 years old. All cases were diagnosed by ultrasonography and their gallbladder functions were proved normal by the examination of oral cholecystography or ECT before operation. In the operation gallstones were removed from gallbladder completely. RESULTS: There were 612 cases who were followed up for 1-15 years and the follow-up rate was 80.5%. All patients recovered well after operation. The post-operation rate of recurrence of gallstone was 0.49%, 4.39%, 5.83%, 6.60%, 7.21% and 8.38% within the first year, the second year, the third year, the fifth year, the seventh year and the ninth year respectively, rate of recurrence of gallstone were 10.11% within both the tenth and the fifteenth year. CONCLUSIONS: The minimal invasive operation with gallbladder preserved via choledochoscopy is effective to cholecystolithiasis patients whose gallbladder function is normal. It is a feasible operation that preserves the normal functional gallbladder and improves the patients' life quality.


Assuntos
Colecistolitíase/cirurgia , Endoscopia do Sistema Digestório/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Seguimentos , Vesícula Biliar/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
8.
Zhonghua Gan Zang Bing Za Zhi ; 14(12): 898-901, 2006 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-17196132

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of a China made adefovir dipivoxil (ADV) treatment for hepatitis B e antigen-positive patients with chronic hepatitis B. METHODS: Two hundred and thirty patients with chronic hepatitis B who were positive for hepatitis B e antigen (HBeAg) were randomly put into groups A or B, and 58 patients with lamivudine-resistant chronic hepatitis B were randomly put into groups C or D. During the first 12 weeks of the trial, 112 patients in group A and 115 patients in group B received 10 mg of ADV and a placebo once a day; 28 patients in group C received 100 mg of lamivudine (LMV) and 10 mg of ADV; 29 patients in group D received 100 mg of LMV and a placebo once a day. In the second trial period, all patients received ADV for 36 weeks. The primary checking criterion was the serum HBV DNA change during the treatment. The secondary ones were alanine aminotransferase (ALT) normalization, HBeAg loss, and HBeAg seroconversion. RESULTS: At week 12, the median serum hepatitis B virus (HBV) DNA level of group A (ADV-ADV) was reduced 2.8 log10 copies/ml, significantly greater than that of group B (placebo-ADV) of 0.3 log10 copies/ml reduction (P = 0.000). At week 48, the median serum HBV DNA level of group A and group B were reduced 3.6 and 3.4 log10 copies/ml respectively. At week 12, the median serum HBV DNA level of group C (LMV+ADV) was reduced 3.0 log10 copies/ml, significantly greater than that of the group D (LMV+placebo) of 0.16 log10 copies/ml reduction (P = 0.000). At week 48, the median serum HBV DNA level of group C and group D were reduced 3.6 and 3.8 log10 copies/ml respectively. Only 5.56% (16/288) patients had adverse events that were mild to moderate. There was no significant difference in the change of serum creatinine compared with their baseline levels. CONCLUSION: In our HBeAg positive lamivudine-resistant chronic hepatitis B patients, 48 weeks of ADV treatment was safe and resulted in significant virological and biochemical improvements.


Assuntos
Adenina/análogos & derivados , Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Organofosfonatos/uso terapêutico , Adenina/uso terapêutico , Adolescente , Adulto , Idoso , Método Duplo-Cego , Farmacorresistência Viral , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/imunologia , Hepatite B Crônica/virologia , Humanos , Pessoa de Meia-Idade , Mutação , Adulto Jovem
9.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 21(1): 46-9, 2005 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-15629082

RESUMO

AIM: To construct human phage antibody library against SARS virus. METHODS: Human Fab genes were amplified by RT-PCR from lymphocytes of a convalescent SARS patient and cloned into vector pComb3 to construct phage antibody library. Antibodies against SARS virus were screened by biopanning with immobilized virus antigen. The binding specificity of phage antibody to SARS virus was detected by ELISA. RESULTS: 13 Ig genes were obtained by PCR. A human phage antibody library consisting of 1.3 x 10(6) clones was constructed by electrotransformation and 60 percent of the clones contained Fab genes. After three rounds of panning with SARS virus antigen, phage antibodies against SARS virus were specifically enriched. ELISA detection verified 10 positive phage antibodies that were highly specific for SARS virus. CONCLUSION: Human phage antibody library against SARS virus has been constructed successfully, from which 10 anti-SARS virus antibodies were obtained.


Assuntos
Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Bacteriófagos/genética , Biblioteca de Peptídeos , Vírus da SARS/imunologia , Animais , Especificidade de Anticorpos , Antígenos Virais/imunologia , Bovinos , Humanos , Reação em Cadeia da Polimerase
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