Quantitative studies of collagen formation by chick embryonic lung tissue grown in media deficient in, or completely lacking, ascorbic acid have been carried out. Cell growth and collagen formation in such cultures can proceed almost normally in media lacking ascorbic acid. Ascorbic acid in combination with whole embryo extract, dialyzed media, or synthetic mixture number 703 was found to have ...

The RNA-P and DNA-P content of the nucleus and the RNA-P content of the whole cell of the livers of 8to 20-day chick embryos and of adult fowls have been determined. The DNA-P content of the liver nuclei was slightly higher in the 8and 10-day embryo than in all the other stages examined. A significant decrease in the RNA content of the cell occurred during embryonic development. The RNA content...

The P1.HTR cell line includes highly transfectable cells derived from P815 mastocytoma cells originating from mouse breast tissue. Despite its widespread use in immunogenic studies, no data are available about the behavior of P1.HTR cells in the chick embryo chorioallantoic membrane model. The objective of the present investigation was to study the effects of P1.HTR cells implanted on the chori...

In this study, immunohistochemical analysis has been performed using neuronal markers (GAP43, NCAM and PGP 9.5) to characterize the epithelial invagination in the medial wall of the olfactory pit in the chick embryos. At stages 26-27, the epithelial invagination was primarily composed of characteristic round-shaped cells, which were negative for neuronal markers. These cells were also found in ...

Thus, Bohnhoff et al. (1) made mice more susceptible to oral challenge with a streptomycin-resistant strain of Salmonella enteritidis by pretreatment with streptomycin. They concluded that this increase in susceptibility resulted from a disturbance of the normal intestinal microflora. Using a similar method, Freter (2-4) was able to induce an asymptomatie carrier state in guinea pigs and mice w...