Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Infect Dis Poverty ; 9(1): 60, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32487256

RESUMO

BACKGROUND: China still suffers heavily from rabies, although reported human cases continue to decrease year over year. There are far fewer laboratory-confirmed human cases than clinically diagnosed cases, which is a big problem that needs to be addressed. In this report, we summarize analyses of all specimens from human cases tested in our laboratory over the past 15 years, in order to promote laboratory diagnosis of rabies. METHODS: From 2005 to 2019, a total of 271 samples from 164 suspected rabies cases were collected from local hospitals by the local Centers for Disease Control and Prevention (CDCs) in China. Saliva, cerebrospinal fluid (CSF), serum (blood) and urine were collected for ante-mortem diagnosis, and brain tissue, neck skin tissue and cornea were collected for post-mortem diagnosis. All of the specimens were tested by reverse transcription-polymerase chain reaction (RT-PCR), and brain tissues were also tested using fluorescent antibody test (FAT). The number of positive test results obtained using different fluids or tissues, and at different stages of the disease, were compared using a chi-square test and a more effective sampling program is recommended. RESULTS: As the national reference laboratory for rabies surveillance in China, our laboratory has tested 271 samples from 164 suspected rabies cases collected by local CDCs since 2005. We found that saliva gave the highest number of positive test results (32%), compared with CSF and other fluids. We also found that serum or blood specimens collected in the last 3 days of life can test positive by RT-PCR. CONCLUSIONS: Serum or blood samples collected in the last 3 days of a patient's life can be used to measure viral RNA, which means that serum samples, as well as saliva and CSF, can be used to detect viral RNA for anti-mortem diagnosis of rabies. Because of our findings, we have modified our "National Surveillance Project for Human Rabies", by adding the collection and testing of serum samples from the end of the survival period. This will improve our national surveillance and laboratory diagnosis of human rabies.


Assuntos
Vírus da Raiva/isolamento & purificação , Raiva/diagnóstico , Manejo de Espécimes/métodos , China , Humanos , Manejo de Espécimes/instrumentação
2.
Infect Dis Poverty ; 7(1): 117, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30514379

RESUMO

BACKGROUND: The injection of rabies immune globulin (RIG) is of the utmost importance in the management of category III exposures to rabies-suspect animals. Because of the high cost and limited availability of existing RIG, one possible replacement for RIG is monoclonal antibodies (MAbs) against the rabies virus (RABV). Consequently, it is necessary to determine the neutralizing activity of the MAbs against rabies viruses, especially street rabies virus. However, the method to detect the neutralizing activity of MAbs against street rabies virus remains undefined. METHODS: To establish a method for detecting the neutralizing activity of MAbs against street rabies virus, we constructed a library consisting of 12 strains of street RABV from 11 provinces in China. Using this street RABV library and the Reed-Muench formula, we established a method for detecting the neutralizing titer of the MAbs. The reliability and repeatability of the method were evaluated by repeatedly measuring the neutralizing activity of a MAb and a post vaccination serum. RESULTS: A total of 12 strains of street RABV were chosen for inclusion in the street RABV library, which covered six Chinese lineages (China I-China VI) and grew to high titers in N2A cells (> 105 FFD50/ml). On the basis of the library, we constructed the method to detect the neutralizing activity of the MAbs. The results of repeatedly measuring the MAbs and positive serum showed excellent reliability and repeatability of the method established in this study. CONCLUSIONS: This study established a street RABV library reflecting the epidemiological features of Chinese rabies viruses, which provides a platform for detecting the neutralizing activity of MAbs against rabies viruses circulating in China.


Assuntos
Vírus da Raiva/genética , Raiva/prevenção & controle , Animais , Anticorpos Monoclonais , Anticorpos Antivirais/imunologia , China/epidemiologia , Biblioteca Gênica , Humanos , Imunoglobulinas/uso terapêutico , Testes de Neutralização , Filogenia , Raiva/epidemiologia , Vacinas Antirrábicas , Vírus da Raiva/classificação , Vírus da Raiva/imunologia
3.
Vaccine ; 36(41): 6053-6060, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30195490

RESUMO

Ebola virus (EBOV) disease (EVD) leads to lethal hemorrhagic fever with a case fatality rate as high as 90%, thus posing a serious global public health concern. However, while several vaccines based on the EBOV glycoprotein have been confirmed to be effective in animal experiments, no licensed vaccines or effective treatments have been approved since the first outbreak was reported in 1976. In this study, we prepared the extracellular domain of the EBOV GP protein (designated as N20) by prokaryotic expression and purification via chromatography. Using CTA1-DD (designated as H45) as a mucosal adjuvant, we evaluated the immunogenicity of N20 by intranasal administration and the associated protective efficacy against mouse-adapted EBOV challenge in mice. We found that intranasal vaccination with H45-adjuvanted N20 could stimulate humoral immunity, as supported by GP-specific IgG titers; Th1 cellular immunity, based on IgG subclasses and IFN-γ/IL-4 secreting cells; and mucosal immunity, based on the presence of anti-EBOV IgA in vaginal lavages. We also confirmed that the vaccine could completely protect mice against a lethal mouse-adapted EBOV (MA-EBOV) challenge with few side effects (based on weight loss). In comparison, mice that received N20 or H45 alone succumbed to lethal MA-EBOV challenge. Therefore, mucosal vaccination with H45-adjuvanted N20 represents a potential vaccine candidate for the prevention of EBOV in an effective, safe, and convenient manner.


Assuntos
Aminoácidos/imunologia , Vacinas contra Ebola/administração & dosagem , Vacinas contra Ebola/uso terapêutico , Ebolavirus/imunologia , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Vacinação/métodos , Administração Intranasal , Animais , Feminino , Imunidade Celular/fisiologia , Imunidade Humoral/fisiologia , Camundongos , Camundongos Endogâmicos BALB C
4.
Infect Dis Poverty ; 7(1): 82, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30107857

RESUMO

BACKGROUND: Rabies, for which the mortality rate is almost 100%, is a zoonotic viral disease that can be transmitted via solid organs or tissue allotransplantation. Dozens of deaths from rabies via solid organs or tissues allotransplantation (ROTA) have been documented during the last decades. In 2015 and 2016, two cases of rabies virus transmission via solid organs or tissue allotransplantation were reported in China, which further underscore the risk and importance of this special type of rabies for organ transplant recipients. MAIN TEXT: From 1978 to 2017, at least 13 cases of ROTA, causing dozens of deaths, have been reported worldwide, whether in the high-risk or low-risk countries of rabies. The reported incubation period of ROTA ranges from 11 days to more than 17 months, while the historical incubation period of rabies is generally considered to range from ~ 1 week to several years. The pathogenesis of ROTA is not clear, but the use of post-exposure prophylaxis (PEP) can play a protective role in the transplant recipients. We also summarize reports about ROTA in China, combined with the actual situation regarding work on rabies surveillance and elimination, and suggest countermeasures for the prevention and control of ROTA in the future. CONCLUSIONS: Understanding the significance of ROTA, screening the suspected organs, assessing the risk and protecting the related population will be effective way to prevent and control further occurrence of ROTA.


Assuntos
Transplante de Órgãos/efeitos adversos , Profilaxia Pós-Exposição/organização & administração , Vacinas Antirrábicas/administração & dosagem , Vírus da Raiva/patogenicidade , Raiva/prevenção & controle , Transplante de Tecidos/efeitos adversos , China/epidemiologia , Feminino , Humanos , Masculino , Transplante de Órgãos/mortalidade , Raiva/epidemiologia , Raiva/mortalidade , Raiva/virologia , Vírus da Raiva/imunologia , Análise de Sobrevida , Transplante de Tecidos/mortalidade , Transplante Homólogo , Vacinação
5.
Biomed Environ Sci ; 31(5): 343-350, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29866216

RESUMO

OBJECTIVE: To eliminate the side effects of aluminum adjuvant and His-tag, we constructed chimeric VLPs displaying the epitope of EV71 (SP70) without His-tagged. Then evaluating whether the VLPs could efficiently evoke not only humoral but also cellular immune responses against EV71 without adjuvant. METHODS: The fusion protein was constructed by inserting SP70 into the MIR of truncated HBcAg sequence, expressed in E. Coli, and purified through ion exchange chromatography and density gradient centrifugation. Mice were immunized with the VLPs and sera were collected afterwards. The specific antibody titers, IgG subtypes and neutralizing efficacy were detected by ELISA, neutralization assay, and EV71 lethal challenge. IFN-γ and IL-4 secreted by splenocytes were tested by ELISPOT assay. RESULTS: HBc-SP70 proteins can self-assemble into empty VLPs. After immunization with HBc-SP70 VLPs, the detectable anti-EV71 antibodies were effective in neutralizing EV71 and protected newborn mice from EV71 lethal challenge. There was no significant difference for the immune efficacy whether the aluminum adjuvant was added or not. The specific IgG subtypes were mainly IgG1 and IgG2b and splenocytes from the mice immunized produced high levels of IFN-γ and IL-4. CONCLUSION: The fusion proteins without His-tagged was expressed and purified as soluble chimeric HBc-SP70 VLPs without renaturation. In the absence of adjuvant, they were efficient to elicit high levels of Th1/Th2 mixed immune response as well as assisted by aluminum adjuvant. Furthermore, the chimeric VLPs have potential to prevent HBV and EV71 infection simultaneously.


Assuntos
Enterovirus Humano A/genética , Infecções por Enterovirus/imunologia , Epitopos/imunologia , Imunidade Celular , Imunidade Humoral , Proteínas Recombinantes de Fusão/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais/sangue , Infecções por Enterovirus/virologia , Epitopos/metabolismo , Escherichia coli/metabolismo , Feminino , Camundongos
6.
Biomed Environ Sci ; 29(6): 417-23, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27470102

RESUMO

OBJECTIVE: Hepatitis Delt a Virus (HDV) antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for this purpose. METHODS: Reconstruct the gene of HDV antigen based on the bias code of Escherichia coli, the recombinant protein expresses by high-density fermentation with fed-batch feeding strategy, and purify by immobilized metal chromatography. The sensitivity and specificity of this antigen detect by ELISA method. RESULTS: The expression of HDV antigen can reach 20% of the total cell mass in the soluble form. The recombinant HDV antigen can be conveniently purified (98%) by immobilized metal ion affinity chromatography (IMAC) using the interaction between a His-tag and nickel ions. Production of recombinant HDV antigen can reach 0.5 g/L under conditions of high-density cell fermentation. Applied to the diagnostic ELISA method, the recombinant HDV antigen shows excellent sensitivity (97% for IgM and 100% for IgG) and specificity (100% for IgG and IgM) for the detection of anti-HDV antibodies. CONCLUSION: Expression and purification the recombinant HDV antigen as a candidate protein for application in a diagnostic ELISA for HDV infection. Large-scale production of the protein can be achieved using the high-density fermentation strategy.


Assuntos
Ensaio de Imunoadsorção Enzimática , Hepatite D/diagnóstico , Vírus Delta da Hepatite/imunologia , Antígenos da Hepatite delta/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , Hepatite D/imunologia , Hepatite D/virologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
7.
Medicine (Baltimore) ; 95(21): e3707, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27227931

RESUMO

Congenital diaphragmatic hernia (CDH) is a rare developmental anomaly of the diaphragm that mainly presents mainly in newborns. Even less common is late-onset CDH associated with hypersplenism. We report a 10-year-old male who presented with coughing, blood-stained sputum, and fever. He was diagnosed with CDH complicating hypersplenism after computed tomography was done. The patient was treated by CDH repair and splenectomy, and remained asymptomatic at 6-month follow-up. Computed tomography can be an important diagnostic option in this rare combination of CDH and hypersplenism, and surgical intervention is strongly recommended.


Assuntos
Hérnias Diafragmáticas Congênitas/complicações , Hérnias Diafragmáticas Congênitas/cirurgia , Hiperesplenismo/complicações , Hiperesplenismo/cirurgia , Criança , Hérnias Diafragmáticas Congênitas/diagnóstico por imagem , Herniorrafia/métodos , Humanos , Hiperesplenismo/diagnóstico por imagem , Masculino , Esplenectomia/métodos , Tomografia Computadorizada por Raios X
8.
Artigo em Chinês | MEDLINE | ID: mdl-24645316

RESUMO

OBJECTIVE: To construct full-length hepatitis B core particles presenting preS1 aa 21-47 epitope and truncated core particles presenting preS1 aa 37-45 epitope on their surface and compare their antigenicity. METHODS: PreS1 aa21-47 epitope and aa 37-45 epitope were inserted respectively into full-length hepatitis B core (aa 1-183) and truncated HBcAg (aa 1-144), between the 78th (Asp) and 79th (Pro). The genes synthesized after the codon optimization were ligated to the pET43. 1a vector with the same cohesive terminal (NdeI and XhoI) and expressed in the E. coli expression system. The morphology of the proteins of interest were observed by electron microscope and characterized by ELISA and Western Blotting. RESULTS: The morphology of the virus-like particles were confirmed by electron microscope. H2 were solid particles with a diameter of (31.61 +/- 1.27) nm, while H3 were hollow particles with a diameter of (28.46 +/- 1.16) nm. Statistical analysis showed that H2 is larger than H3 in the diameter (P < 0.01). The antigenicity of the inserted epitopes and carrier protein were identified by ELISA and Western Blotting. CONCLUSION: Chimeric hepatitis B core particles presenting the preS1 neutralizing epitopes on their surface have been expressed, purified and identified, which lays the foundation for its application in vaccine research.


Assuntos
Epitopos/imunologia , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Precursores de Proteínas/imunologia , Epitopos/química , Epitopos/genética , Hepatite B/virologia , Antígenos do Núcleo do Vírus da Hepatite B/química , Antígenos do Núcleo do Vírus da Hepatite B/genética , Antígenos de Superfície da Hepatite B/química , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/química , Vírus da Hepatite B/genética , Humanos , Testes de Neutralização , Precursores de Proteínas/química , Precursores de Proteínas/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia
9.
Artigo em Chinês | MEDLINE | ID: mdl-24579478

RESUMO

OBJECTIVE: To overexpress hepatitis B virus S gene in CHO cells cultured in serum-free media. METHOD: Plasmid was constructed by cloning of HBV S gene and then it was transfected into CHO cells. After cell screen, the positive clones were identified and isolated into a serum-free media followed by the serological and morphological characterization of the expression product. RESULT: CHO cell strains which can express HBsAg efficiently and stably were obtained. Spherical and filamentous HBsAg could be detected under electronic microscope. The titer of the expression product was up to 1:5000. CONCLUSION: Serum-free media cultured CHO cell strain for overexpression of HBsAg was successfully constructed and the expression product was high antigenic.


Assuntos
Expressão Gênica , Antígenos de Superfície da Hepatite B/genética , Animais , Células CHO , Cricetinae , Cricetulus , Antígenos de Superfície da Hepatite B/imunologia , Transfecção
10.
Artigo em Chinês | MEDLINE | ID: mdl-23002540

RESUMO

OBJECTIVE: To prepare HDAg with biological activities as a candidate of diagnostic reagent. METHODS: To synthesize HDV gene fragment after codon optimization. To construct a thio-fused recombinant plasmid based on M48 expression vector. To express in E. coli induced by IPTG. To purify the protein by affinity chromatography followed by characterization in ELISA: RESULTS: Plasmid construction was verified by enzyme digestion. SDS-PAGE indicated the molecular weight of the protein was the same as we expectation. ELISA proved its affinity with HDV antibodies. CONCLUSION: HDAg was obtained successfully and it will pave the road to the research of HDV diagnostic reagent.


Assuntos
Hepatite D/diagnóstico , Antígenos da Hepatite delta/imunologia , Ensaio de Imunoadsorção Enzimática , Antígenos da Hepatite delta/genética , Antígenos da Hepatite delta/isolamento & purificação , Humanos , Plasmídeos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação
11.
Artigo em Chinês | MEDLINE | ID: mdl-23547452

RESUMO

OBJECTIVE: To study the effect of gene optimization on the expression and purification of HDV small antigen produced by genetic engineering. METHODS: Based on the colon preference of E. coli, the HDV small antigen original gene from GenBank was optimized. Both the original gene and the optimized gene expressed in prokaryotic cells, SDS-PAGE was made to analyze the protein expression yield and to decide which protein expression style was more proportion than the other. Furthermore, two antigens were purified by chromatography in order to compare the purity by SDS-PAGE and Image Lab software. RESULTS: SDS-PAGE indicated that the molecular weight of target proteins from two groups were the same as we expected. Gene optimization resulted in the higher yield and it could make the product more soluble. After chromatography, the purity of target protein from optimized gene was up to 96.3%, obviously purer than that from original gene. CONCLUSION: Gene optimization could increase the protein expression yield and solubility of genetic engineering HDV small antigen. In addition, the product from the optimized gene group was easier to be purified for diagnosis usage.


Assuntos
Engenharia Genética/métodos , Antígenos da Hepatite delta/genética , Proteínas Recombinantes/biossíntese , Eletroforese em Gel de Poliacrilamida , Hepatite D/diagnóstico , Antígenos da Hepatite delta/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação
12.
Artigo em Chinês | MEDLINE | ID: mdl-23547464

RESUMO

OBJECTIVE: To investigate the seroprevalence of hepatitis D virus in Foshan of Guangdong province, to provide the data for the study about it in China. METHODS: ELISA kits from two different companies were used for detecting anti-HDV IgG of all the serum samples, and then RT-PCR was carried out about the selected serum to ensure the results. All the serum samples were collected in 2011 in The First People's Hospital of Foshan. RESULTS: The results from two ELISA kits and RT-PCR were identical. Eight samples were positive. CONCLUSIONS: The seroprevalence rate of HDV in Foshan is higher than that in China. It has no statistically significant difference between female and male. Morever, the older with HBsAg are susceptible to HDV.


Assuntos
Coinfecção/epidemiologia , Antígenos de Superfície da Hepatite B/sangue , Hepatite B/epidemiologia , Hepatite D/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , China/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...