The non-pathogenic (unadapted) line of the Rhodes strain of influenza virus multiplied readily in the mouse lung, but its rate of multiplication was slower and its hemagglutination titer attained at the peak of growth was much lower than that of the adapted line of the same virus. The implication of these findings to mouse adaptability of the virus is discussed.

The role of the cell nucleus in the development of African swine fever virus in Vero cells has been studied. No viral growth could be detected in enucleated cells under conditions that allow normal development of Sindbis virus. Furthermore, African swine fever virus DNA synthesis was inhibited more than 95% after infection of enucleated Vero cells as compared with normal cells.

Human rhinovirus type 14 contained polyadenylated RNA. Virus growth in HeLa cells was inhibited by cordycepin or polyuridilic acid and stimulated by polyadenylic acid. Polyadenylic acid also reversed cordycepin inhibition of virus-induced cytopathology of infected HeLa cells.

For preparation of antigen, cells from an ascites lymphoma, induced by the Gross virus and transplanted in syngeneic C3H/BÃŒmice, were infected with parainfluenza I or Newcastle disease virus. After 48 hr of incubation to permit growth of virus, cells were extracted by freezing and thawing in 0.03% NaCl solution. Extracts representing about IO7tumor cells were injected repeatedly at intervals

Pseudorabies virus has been cultivated in series in rabbit testicle, guinea pig testicle, and chick embryo media, and its growth requirements have been studied. Intranuclear inclusions, similar to those produced by pseudorabies virus in vivo, have been found in rabbit testicle cultures. The virus has not changed its pathogenic properties for rabbits, guinea pigs, or mice during the course of cu...

The Epstein-Barr virus (EBV) is a B lymphotropic virus that infects the majority of the human population. All EBV strains transform B lymphocytes, but some strains, such as M81, also induce spontaneous virus replication. EBV encodes 22 microRNAs (miRNAs) that form a cluster within the BART region of the virus and have been previously been found to stimulate tumor cell growth. Here we describe t...

Extracts of canine liver inhibited growth of infectious canine hepatitis (ICH) virus, a canine adenovirus. Purified extracts from mammalian, but not avian, liver tissue contained the inhibitor, and evidence is presented that the inhibitory factor is the enzyme arginase (arginine ureohydrolase). This study further emphasized the need for arginine in adenovirus growth and may explain some of the ...

Production of HVJ (Sendai virus) wild-type in rat glial cells was characteristically restricted at high temperature. The synthesis of the M protein was selectively decreased in infected cells at 39 degrees C. This temperature-sensitive (ts) character of HVJ was not observed in infection of LLCMK2 cells or chick embryo fibroblast cells. Newcastle disease virus, mumps virus and vesicular stomatit...

The antiviral mode of action of the synthetic brassinosteroid (22S,23S)-3beta-bromo-5alpha,22,23-trihydroxystigmastan-6-one (6b) against replication of vesicular stomatitis virus (VSV) in Vero cells was investigated. Time-related experiments showed that 6b mainly affects a late event of the virus growth cycle. Virus adsorption, internalisation and early RNA synthesis are not the target of the i...