RESUMEN
Coinfected mice were examined for a possible interaction between the scrapie agent and an adenovirus. A low titer (10(2) TCD50) of mouse adenovirus (MAdV) caused a significant acceleration of clinical signs of scrapie in mice infected 128 days previously with scrapie. In this experiment, the coinfected mice died 19 days earlier than mice infected with scrapie alone. When a higher titer of MAdV (10(4)-10(5) PFU) was used, a more drastic acceleration of scrapie disease was seen in mice infected 85 and 110 days previously with scrapie. At 85 days, coinfection caused mice to die 37 days earlier than mice infected with scrapie alone, whereas at 110 days, coinfection caused mice to die 52 days earlier than mice infected with scrapie alone. MAdV alone caused no clinical disease in normal mice. The brains of coinfected mice and mice that had been infected with scrapie alone showed a histopathology consistent with scrapie. A possible explanation for these findings is that the replication of the scrapie agent is accelerated by adenovirus. Defective parvoviruses are known to be helped by adenoviruses. Spleens from coinfected mice but not from mice infected with MAdV alone yielded, in cultures of BALB 3T3 cells, infectious MAdV and one or two smaller agents with the dimension and shape of a parvovirus.
Asunto(s)
Infecciones por Adenoviridae/complicaciones , Encéfalo/microbiología , Scrapie/complicaciones , Adenoviridae/fisiología , Infecciones por Adenoviridae/microbiología , Infecciones por Adenoviridae/patología , Animales , Encéfalo/patología , Cerebelo/patología , Corteza Cerebral/patología , Hipocampo/patología , Ratones , Priones/aislamiento & purificación , Priones/fisiología , Scrapie/microbiología , Scrapie/patología , Bazo/microbiología , Replicación ViralRESUMEN
Proteins associated with 36S virus RNA from Vero cells infected with San Miguel sea lion virus, type 2 (SMSV-2), were labelled with 125I. One protein, VPg, remained linked to RNA when subjected to deproteinization techniques. VPg labelled wtih 32P was observed on 36S RNA from purified virions; the quantity of label was compatible with two phosphates per genome. The estimated mol. wt. of SMSV-2 VPg was 15 000.
Asunto(s)
Caliciviridae/análisis , ARN Viral/análisis , Proteínas Virales/análisis , Animales , Células Cultivadas , Fraccionamiento Químico , Electroforesis en Gel de Poliacrilamida , Peso Molecular , Nucleósidos/aislamiento & purificación , Desnaturalización Proteica , Phocidae , Replicación ViralRESUMEN
RNA labeled with [3H]uridine from Vero cells infected with San Miguel sea lion virus in the presence of actinomycin D was analyzed by glycerol density gradient sedimentation and polyacrylamide gel electrophoresis. The predominant single-stranded RNA (36S, 2.6 x 10(6) molecular weight) was genome size. There was also a prominent 22S, 1.1 x 10(6)-molecular weight, single-stranded component and one or more double-stranded or partially double-stranded classes. Replicative forms, sedimenting at 18S, contained single-stranded RNA corresponding to the larger-molecular-weight class. All classes of intracellular RNA and virion RNA were polyadenylated. These findings and results with pig kidney cells infected with vesicular exanthema of swine virus and feline cells infected with feline calicivirus indicate that caliciviruses exhibit a strategy of replication different from typical picornaviruses and supports removal of the caliciviruses from the family Picornaviridae.
Asunto(s)
Picornaviridae/análisis , ARN Viral/análisis , Animales , Caniformia , Línea Celular , Dactinomicina/farmacología , Peso Molecular , Picornaviridae/clasificación , Picornaviridae/metabolismo , Poli A/análisis , ARN Viral/biosíntesisRESUMEN
A method is described which is suitable for assessing the effects of relative humidity (RH) on the viability of two unicellular algae in experimental aerosols. Viable cells of Nannochloris atomus collected from the airborne state were detected by plating onto agar surfaces of an appropriate growth medium, whereas viable airborne cells of Synechococcus sp., because of unreliable growth on solid media, were determined by a liquid assay system. The assays were performed at intervals during short-term and prolonged storage of algal aerosols in chambers preconditioned to a selected RH and temperature. Both species showed the greatest loss in viability during the first minute after atomization, and the extent of this inactivation, as a function of RH, reflected the subsequent long-term survival. The airborne eukaryotic alga was unable to survive at an RH below 91%, whereas the airborne prokaryotic alga was comparatively stable over a wide humidity range. Initial inactivation was least and long-term survival best, for both species, at 94% RH.
Asunto(s)
Microbiología del Aire , Eucariontes , Humedad , Aerosoles , Recuento de Células , Supervivencia Celular , Eucariontes/crecimiento & desarrollo , Eucariontes/aislamiento & purificaciónRESUMEN
Extracts from two species of marine red algae, Cryptosyphonia woodii and Farlowia mollis, specifically inhibited herpes simplex virus replication in vitro.