Infection of human erythroleukemic K562 cells by encephalomyocarditis virus readily resulted in establishment of persistently infected cultures. In contrast to the usual typical lytic infection by encephalomyocarditis virus, in which trypan blue staining of cells reaches close to 100% by about 15 h postinfection, K562 cell cultures required 3 to 4 days postinfection to reach a maximum of about ...

1. Denatured tobacco mosaic virus has a number of SH groups corresponding to its total sulfur content of 0.2 per cent. The SH groups were estimated by titration with ferricyanide, tetrathionate, and p-chloromercuribenzoate in guanidine hydrochloride solution and by reduction of the uric acid reagent in urea solution. 2. The SH groups of tobacco mosaic virus or their precursors can be abolished ...

After aerosolization of a bovine strain of parainfluenza type 3 virus, the pathogenesis of the virus was followed from the trachea to the bronchioalveolar compartments of the lung of colostrum-free calves and of conventionally reared calves during a 5- to 12-day postexposure interval. By tissue titration, plaque assay, and electron microscopy, it was found that virus infection could be establi...

Vero cells used by distinct measles vaccine control laboratories had their susceptibility to Moraten, Schwarz and Biken CAM-70 vaccine strains assayed. Of a total of 72 lots of measles vaccine whose potency was titrated by microtechnique in two Vero cell samples (Vero IB and Vero INCQS), 25 had been produced with Moraten strain, 24 with Schwarz and 23 with Biken CAM-70. The statistical analysis...

INTRODUCTION The cryopreservation of rabies virus has been described in detail in the literature. To date, little information is available on the use of cryoprotective agents for cold preservation of this virus, and the available data focus only on short-term virus preservation. In this study, we investigated the medium-term cryopreservation of samples of rabies virus using different cryopreser...

Foot-and-mouth disease (FMD) is a highly contagious, economically important virus disease of cloven-hoofed animals. The objective of the present study was to examine the early pathogenesis of FMD in pigs by a quantitative time-course study. Under experimental conditions, recipient pigs were infected by contact with donor pigs affected by FMD. Every 24 h from day 1 to day 4 after exposure, two r...

Polyomaviruses have repeating sequences at their origins of replication that bind the origin-binding domain of virus-encoded large T antigen. In murine polyomavirus, the central region of the origin contains four copies (P1 to P4) of the sequence G(A/G)GGC. They are arranged as a pair of inverted repeats with a 2-bp overlap between the repeats at the center. In contrast to simian virus 40 (SV40...