1. Treatment ofthe chick embryo with the lathyrus factor, ,-aminopropionitrile, produces inhibition of polymerization of newly synthesized collagen at the interand intra-molecular level (Levene & Gross, 1959; Martin, Gross, Piez & Lewis, 1961); this is manifest as an increase in the fragility and solubility of collagen from the connective tissues. 2. This treatment simultaneously produced incre...

The effects of papain protease and of vitamin A on explanted limb bone rudiments from 7- and 13-day chick embryos and fetal mice have been studied and compared. The incubation of cartilaginous rudiments from 7-day chick embryos in a solution containing papain and cysteine resulted in complete loss of the metachromasia of the cartilage matrix within 1 hour; explants treated in this fashion recov...

The effect of gamma-butyrobetaine alone and with the addition of carnitine on the development of the early excised chick embryo has been studied. gamma-Butyrobetaine in appropriate amounts exerts an inhibitory effect which can be relieved or annulled by the inclusion of appropriate amounts of carnitine. This has been interpreted as a metabolite-antimetabolite relationship, in which the normal m...

A chick gene homologous to the Drosophila homeobox gene labial has been cloned and sequenced. Regions of additional sequence identity outside of the homeobox reveal a close relationship to the mouse gene Hox 1.6. Northern blot analysis demonstrates that Ghox-lab and Hox 1.6 transcripts are both present at high levels during early stages of chick and mouse development, with a subsequent decline ...

A microsomal preparation from chick embryo cartilage has been shown to catalyze the incorporation of sulfate-36S from 3’-phosphoadenosine 5’-phosphosulfate-3% into microsomal glycosaminoglycan. This enzyme preparation is the same preparation that previously has been shown to catalyze the formation of chondroitin (nonsulfated) from sugar nucleotide precursors. The microsomal sulfate acceptor app...

1. Foreign body giant cells may be produced in vitro by the addition of foreign objects such as lycopodium spores and cotton fibers to cultures of chick embryo spleen. 2. These giant cells are formed by the fusion of large mononuclear wandering cells, probably endothelial cells and pulp cells. Connective tissue cells do not take part in their formation. 3. The large giant cells sometimes seen s...

The micronucleus (MN) test in bone-marrow and peripheral blood erythrocytes is one of the best established in vivo cytogenetic assays in the field of genetic toxicology, providing a convenient and reliable index of both chromosome breakage and chromosome loss. Therefore a study was made on micronuclei assay to evaluate the degree of genotoxicity of acrylamide and its toxicologic effects on chic...

The several and sometimes paradoxical effects of cortisone and its analogues on the course of a variety of infections may be duplicated in the relatively simple chick embryo-influenza virus model in which the interrelationships of a single obligate intracellular parasite and the cells of a single target organ (the allantoic entoderm) may be examined. Even in this simple system the influence of ...

The establishment of a successful plaque method for counting infectious virus particles by Dulbecco (1952), with subsequent refinements by Dulbecco and Vogt (1953, 1954a), makes it possible to quantitatively assay animal viruses with a high degree of accuracy in a manner comparable to assays of bacterial viruses. Two methods of assay commonly used in characterizing any particular Newcastle dise...