RESUMO
During the month of February, the Ministry of Health and Population in Egypt reported two new human cases of Avian Influenza A [H5N1] including one death to WHO. These two cases are reported for the first time in 2017. Since March 2006, Egypt reported a total of 358 laboratory confirmed cases of Avian Influenza A [H5N1] including 122 deaths [CFR: 34.08%]
Assuntos
Humanos , Feminino , Masculino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Influenza Aviária/epidemiologia , Vírus da Influenza A/fisiologia , Virus da Influenza A Subtipo H5N1RESUMO
El virus influenza es causa frecuente de infección respiratoria. Pertenece a la familia Orthomixoviridae, existiendo tres géneros. Todos comparten características estructurales con un manto de lípidos y glicoproteínas hemaglutinina y neuraminidasa, que participan en la patogenicidad viral y determinando los diferentes subtipos de virus; en su interior una hebra de ácido ribonucleico de polaridad negativa. El presente artículo resumen las principales características de laboratorio, clínicas y de diagnóstico de este emergente virus respiratorio.
Assuntos
Humanos , Influenza Humana/diagnóstico , Influenza Humana/virologia , Vírus da Influenza A/fisiologia , Vírus da Influenza A/patogenicidade , RNA Viral/fisiologia , Influenza Humana/epidemiologia , Laboratórios , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/genéticaRESUMO
The mitochondrial pathway of swine influenza virus (SIV)-induced apoptosis was investigated using porcine kidney (PK-15) cells, swine testicle (ST) cells, and HeLa cervical carcinoma cells which are known not to support viral replication. As judged by cell morphology, annexin V staining, and DNA fragmentation, PK-15 and ST cells infected with three different subtypes of SIV (H1N1, H3N2, and H1N2) were obviously killed by apoptosis, not necrosis. SIV infection in PK-15 and HeLa cells was shown to decrease the cellular levels of Bcl-2 protein compared to that of mock-infected control cells at 24 h post-infection, whereas expression levels of Bax protein increased in the PK-15 cells, but did not increase in HeLa cells by SIV infection. Cytochrome c upregulation was also observed in cytosolic fractions of the PK-15 and HeLa cells infected with SIV. Apoptosome (a multi-protein complex consisting of cytochrome c, Apaf-1, caspase-9, and ATP) formation was confirmed by immunoprecipitation using cytochrome c antibody. Furthermore, SIV infection increased the cellular levels of TAJ, an activator of the JNK-stressing pathway, and the c-Jun protein in the PK-15 and HeLa cells. Taken together, these results suggest that the mitochondrial pathway should be implicated in the apoptosis of PK-15 cells induced by SIV infection.
Assuntos
Animais , Humanos , Anexina A5/metabolismo , Apoptose , Western Blotting , Fracionamento Celular , Linhagem Celular , Estudo Comparativo , Grupo dos Citocromos c/metabolismo , Citosol/química , Fragmentação do DNA , Ativação Enzimática , Regulação Viral da Expressão Gênica , Células HeLa , Vírus da Influenza A/fisiologia , Cinética , Mitocôndrias/metabolismo , Testes de Precipitina , Proteínas Proto-Oncogênicas c-bcl-2/genética , Suínos , Proteína X Associada a bcl-2/genéticaRESUMO
Influenza A viruses exhibit segmented nucleic acid coding for eight different proteins, two of them as glycoproteins exposed on their lipoprotein envelopes, hemagglutinin (HA) and neuraminidase (NA). Hemagglutinin exhibits recptor-binding activity while neuraminidase develps sialidase cleavage activity which acts on cell receptors. Influenza A strains responsible for human, avian, equine and porcine respiratory infections all over the world present antigenically different hemagglutinin (H1 to H14) and neutraminidase (N1 to N9) structures on their surface. The objective of the present investigation was study the role of N2, N8 and N9, anti-genically diverse neuraminidase structures of human (N2) and animal (N8 and N9) influenza viruses, in the receptor-binding process. REceptor-binding activity of N2 and N8 was anlyzed by crossed tests using H3N2 and H3N8 antisera and the hemagglutination inhibition test as a model. Hemangglutinating activity of antigenically different N2 and N8 structures was demonstrable and was inhibited by homologous antisera (N2-H3N2, N8-H3N8) but not by heterologous antisera (N2-H3-N8,N8-H3-N2). This previously demonstrated N9 hemagglutinating activity was analysed for receptor-binding specificity using hemagglutination test and NeuAc alpha2,3Gal and NeuAc alpha2,6Gal derivatized erythrocytes. This highly purified N9 strain was obtained from a virus strain isolated from terns by Dr. Peter Colman (CSIRO Division of Biomolecular Engineering, Parkville, Victoria, Australia)...
Assuntos
Hemaglutininas Virais/fisiologia , Hemaglutinação por Vírus/fisiologia , Neuraminidase/fisiologia , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologiaRESUMO
Se estudiaron eritrocitos de cobayo adsorbidos con virus de influenza antes y despupés de elución viral respecto a los sitios de adhesión viral. Una o dos partículas virales pueden adsorberse sobre microvellosidades de equinocitos libres y a veces pueden también pegarse sobre el cuerpo de un eritrocito adyacente. Después de la elución viral se pueden observar con microscopía electrónica de barrido de alta resolución gran cantidad de "lesiones" en la superficie celular. Los eritrocitos nucleados de pollo, adsorbidos en las mismas condiciones con el mismo líquido alantoideo infectado, no presentaron ni deformaciones, ni microvellosidades, y la unión de las particulas virales a las células era poco firme. La movilidad electroforética de los eritrocitos de cobayo, tanto viviente como fijados, disminuyó el 27% por la adsorción y la elución de partículas virales