Infection of chick embryos wih either Newcastle disease virus or mumps virus and infection of BGM cell cultures with mumps virus result in the elaboration of chemotactic activity for neutrophils and macrophages. These factors cannot be found in lysates of uninfected cells. They do not appear to be associated with the viral particles per se, but rather are present in virus-free supernates from i...

Background: This study was carried out to evaluate the pattern of reactive oxygen species (ROS) variations during in vitro oocyte maturation and embryo development in sheep, and to investigate whether embryo culture condition and the presence of cell-permeable superoxide dismutase mimetic [Manganese (III) meso-tetrakis (4-benzoic acid) porphyrin (MnTBAP)] can influence ROS pattern. Materials an...

Cells were isolated from the somite mesoderm and from the unsegmented (presomite) mesoderm of early chick embryos and exposed to actinomycin D in single cell culture. Actinomycin D inhibited proliferation in cell cultures derived from the unsegmented mesoderm, although the same concentrations of this antibiotic did not inhibit cultures derived from the somite mesoderm. This differential sensiti...

background: successful embryo transfer (et) technique is a fateful step of all efforts to achieve live births from in vitro produced embryos in assisted reproductive techniques or in knockout, transgenic or cloned animal projects. small reproductive tract of mice and limitation of current techniques may not well satisfy the requirements for mass production of genetically modified mice. genetic ...

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology (1). Although development and growth of mammalian embryos are critically dependent on the function of the placenta, WEC technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages during embryoni...

Many methods are available for determining the sensitivity of M. tuberculosis to various chemotherapeutic agents. These may be divided broadly into three groups. In the first group the streptomycin is incorporated into solid media, such as that of Herrold (1931) or of Lowenstein (1930) and Jensen (1932) (Pyle, 1947; Johnson, 1950; Youmans, Ibrahim, Sweany, and Sweany, 1950; Tinne and Henderson,...

Bang and Ellerman, and later Peyton Rous, reported the first identification of transmissible cancer-causing agents, which later turned out to be avian retroviruses. Today avian retroviruses are important models for study of retrovirus replication and pathogenesis, and also important pathogens of domestic fowl. Here we describe the use of RNA interference (RNAi) in live chick embryos to block re...

Research in anatomy, embryology, and developmental biology has largely relied on the use of model organisms. In order to study development in live embryos model organisms, such as the chicken, are often used. The chicken is an excellent model organism due to its low cost and minimal maintenance, however they present observational challenges because they are enclosed in an opaque eggshell. In or...