Chick embryo heart cells in tissue culture actively oxidize [1-(14)C]palmitate to (14)CO(2). Fatty acid oxidation by cell monolayers was linear with time and increasing protein concentration. The addition of carnitine to the assay medium resulted in a 30-70% increase in the rate of fatty acid oxidation. The specific activity of palmitic acid oxidation did not change significantly with time in c...

This study evaluates the suitability of flow cytometry with the fluorochrome BCECF for measuring the intracellular pH (pHi) of cultured cells, and monitors the changes in pHi in murine hybridoma in batch culture and chick embryo fibroblast in monolayer culture (5th passage). The technique produced highly reproducible, repeatable results. The theoretical sensitivity from the calibration curve wa...

Normally, about half of the ciliary ganglion neurons in 8-day-old chick embryos die before day 14 in ovo. However, when dissociated ciliary ganglion neurons were prepared from either 8- or 14-day-old embryos and grown in cell culture with skeletal myotubes, essentially all of the neurons survived for at least 3 weeks. Many of the neurons formed functional synapses on myotubes under these condit...

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...

PURPOSE The molecular mechanism underlying retinal ganglion cell (RGC) differentiation is not fully understood. In this study, the role of the basic helix-loop-helix (bHLH) genes ath5 and NSCL1 in RGC differentiation was examined, by testing whether their coexpression would promote RGC differentiation to a greater extent than either gene alone. METHODS The replication-competent avian RCAS ret...

Between 8 and 12 days of incubation the embryonic duodenum serially constructs with relative regularity the previllous ridges upon which the definitive villi later form. The effects of cytochalasin B (CB) on the formation of these previllous ridges of the duodena of developing chick embryos were studied, varying the concentrations and exposure time of CB in the organ culture system. The results...

In general, seasonal influenza vaccines are trivalent, containing a mixture of influenza A and B strains thought most likely to circulate in the coming season. However, monovalent vaccines have been produced against candidate pandemic strains. It is now common practice to use reassortant strains for production that give high yields of the appropriate surface antigens. Reassortant strains for va...

Erythropoietic cell cultures from very early chick blastoderms survive for several days They show four to seven doublings of the erythroid cells and the appropriate morphological changes from proerythroblasts to mature erythrocytes Cell cycle times are the same as in ovo for the first day of culture, but slow down thereafter The hemoglobins of both the primitive and the definitive red cell seri...

The development of glutamine synthetase (GS) in the neural retina of chick embryos has recently been employed in studies on the control of specific biosynthesis in differentiating cells (Kirk and Moscona, 1963; Moscona and Kirk, 1965). Retinal GS activity is characterized by a sharp increase that begins about the 16th day of embryonic development, continues until after hatching, and coincides w...

A number of workers have employed tissue culture techniques in pneumoconiosis research since Fenn (1921) examined the phagocytosis of quartz and coal by rat exudate leucocytes. However, most attention has been directed to the degree of phagocytosis achieved rather than to evaluating accurately the toxicity of dust to the phagocytic cell. Moreover, the techniques used did not provide concordant ...