Theiler's murine encephalomyelitis virus is divided into two subgroups on the basis of their different biological activities. GDVII subgroup strains cause acute and fatal encephalomyelitis in mice, while TO or DA subgroup strains cause non-fatal polioencephalomyelitis in weanling mice followed by virus persistence and demyelination in the spinal cords. Nonstructural leader (L) protein is encode...

INTRODUCTION Vaccines and antiviral drugs are the most widely used methods of preventing or treating Influenza virus infection. The role of sea buckthorn (SBT) bud dry extract as a natural antiviral drug against Influenza was investigated. METHODS Influenza virus was cultured in the MDCK cell line, with or without SBT bud extract, and virus growth was assessed by HA and TCID50 virus titration...

We report the rescue of a defective vaccinia virus, forming the basis for a stringent selection protocol to generate replicating recombinant virus without the need for marker cassettes and selection agents. Plaques of recombinant virus could be isolated solely by their ability to grow in wild-type cells normally supporting the growth of vaccinia virus. All growth-competent clones analyzed conta...

One-step growth curves of five strains of influenza A, one strain of swine influenza, and three strains of influenza B virus have been analyzed. The influenza A and swine influenza strains showed constant periods of 5 to 6 hours before newly formed virus was liberated from the infected cells, whereas 8 to 10 hours elapsed in the case of the influenza B strains. The yield of virus in the allanto...

This report describes the successful generation of an influenza B transfectant virus altered in RNA segment 6, which encodes the neuraminidase (NA) protein. The procedure for selection of the transfectant virus relies on the use of strain-specific anti-NA monoclonal antibodies to inhibit growth of the helper virus within the system. A transfectant virus has been engineered which has a coding ch...

In the preceding two papers (1, 2) we have described aberrant strains of rabbit fibroma virus, a virus which normally gives rise to fibroma-like growths at the site of inoculation in cottontail or domestic rabbits (3). Those chiefly studied were derived from a growth in one cottontail rabbit (A); the strain in its original form is designated "original fibroma virus," fibromatous virus or OA str...

This experiment was conducted to determine the effects of Myrtle Essential Oil (MEO) on growth performance, carcass characteristics, antibody titer and blood parameters of broiler chickens. A total of 200 Ross 308 broiler chickens were allocated to five dietary treatments with four replicates of 10 birds each. Dietary treatments were prepared by formulating a corn-soybean meal-based diet free o...