RESUMEN
Porcine circovirus type 2 (PCV2) nucleic acid and/or antigens are consistently observed in cells of monocytic morphology in lesions of pigs affected by post-weaning multisystemic wasting syndrome (PMWS). In this study, PCV2 antigen was detected in the cytoplasm of monocytes, pulmonary macrophages (PMs) and monocyte-derived macrophages exposed to the virus in vitro, by immunofluorescence analysis (IFA) and the phenotype of these cells confirmed by detection of monocytic cell surface markers using flow cytometry. Viral antigen was not observed in lymphocytic cells. Replication of the virus in PMs was investigated further by comparison to that observed in the continuous pig kidney cell line (PK15A) using quantitative virus titration, quantitative PCR and by the detection of double stranded DNA intermediates of viral replication by Southern blotting analyses. Although increases in viral DNA and levels of infectious virus progeny and the presence of replicative intermediates, indicative of viral replication, were observed in PK15A cells, no such changes were observed in PMs in spite of the fact that infectious virus, viral antigen and viral DNA persisted in the cells for at least the duration of the experiment. These results suggest that in vivo, monocytic cells may not represent the primary target for PCV2 replication.
Asunto(s)
Infecciones por Circoviridae/veterinaria , Circovirus/fisiología , Leucocitos Mononucleares/virología , Macrófagos Alveolares/virología , Enfermedades de los Porcinos/virología , Síndrome Debilitante/veterinaria , Animales , Antígenos Virales/inmunología , Southern Blotting/veterinaria , División Celular/inmunología , Infecciones por Circoviridae/inmunología , Infecciones por Circoviridae/virología , Circovirus/genética , Circovirus/inmunología , ADN Viral/química , ADN Viral/genética , Citometría de Flujo/veterinaria , Técnica del Anticuerpo Fluorescente Directa/veterinaria , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/inmunología , Macrófagos Alveolares/citología , Macrófagos Alveolares/inmunología , Reacción en Cadena de la Polimerasa , Porcinos , Enfermedades de los Porcinos/inmunología , Replicación Viral , Síndrome Debilitante/inmunología , Síndrome Debilitante/virologíaRESUMEN
Because the Carboniferous deposits at Joggins, Nova Scotia, contain the earliest fauna of terrestrial vertebrates, the extremely well-preserved teeth of these ancient animals are of special interest. The " mineral" composition of teeth from the Joggins microsaur Hylerpeton dawsoni is crystallochemically identical with francolite, a carbonate fluorapatite. The fluorine content of the fossilized dentin is 3.1 percent, which is much higher than any previoulsly recorded for fossil teeth.
