A new antibiotic, ascochlorin, C23H29O4CI, was obtained from the filter cake of the fermented broth of Ascochyta viciae Libert. Ascochlorin inhibits plaque formation of both DNA and RNA viruses in the agar-diffusion plaque inhibition method. However, it showed no antiviral activity by the tube culture method. It showed cytotoxicity to chick embryo fibroblast monolayer and HeLa cells at a concen...

Cells of the Krebs ascites tumor of mice grow well in the body of the chick embryo until about the 17th day of incubation, when degeneration of the tumor can be seen in tissue sections and viable tumor cells begin to disappear from the internal organs of the embryo. This death of tumor cells follows the appearance in the chick embryo of serum gamma globulins. Among these are antibodies which ca...

Both Hensen's node, the organizer center in chick embryo, and exogenous retinoic acid are known to induce limb duplication when grafted or applied to the host chick limb bud. Retinoic acid is known to be present in the node and has been proposed as the putative morphogen for chick limb development. Here, we report that Hensen's node from vitamin A-deficient quail embryo induces limb duplication...

A study of the activity and distribution of glutamic dehydrogenase in various tissues of the developing chick embryo has recently been made (Solomon, 1957). It was found that glutamic dehydrogenase showed marked fluctuations of activity in certain tissues at various stages of development. However, as only relatively low amounts of the enzyme were found in all tissues of the chick embryo and fow...

The chick embryo has played a major role in the advance of our understanding of embryonic development. It has been particularly helpful in relation to amniotes like the mouse, for unlike the mouse in the early embryo the epiblast is beautifully flat, while in the mouse it is all curled up. Here I briefly describe some history and a few of the major achievements that came from the chick embryo.

Introduction: There is considerable evidence that glutamate-mediated excitatory neurotransmission plays an important role in mediating the behavioral actions of acutely administered ethanol. The aim of the present study was to investigate the effect of acute ethanol exposure on NR1 subunit of NMDA (n-methyl-d-aspartate) receptor distribution in the cerebral cortex of chick embryo on the 10th...

Cell-to-cell recognition must play an important role in the nervous system during the formation and maintenance of specific connections between neurons and their target cells. This process of recognition in the nervous system might be based on ( I ) complementarity of structural components in the presynaptic and postsynaptic membranes of appropriate pairs of cells, ( 2 ) the release of a chemic...

Evidence was obtained indicating differences in the survival rate of Western equine encephalomyelitis virus after exposure to ultraviolet radiation and methyl methanesulfonate in commercial and leukosisfree chick embryo cells that differed in repair activity. The levels of spontaneous mutagenesis (on the basis of the yield of small palque variants of the encephalomyelitis virus) did not essenti...

It has been demonstrated that hypophysectomy decreased the rate of incorporation of radiosulfate into cartilage of rats and that the administration of growth hormone resulted in a remarkable rise of the uptake of labeled sulfate (Ellis et al., 1953;Denko and Bergenstal, 1955; Murphy et al., 1956). In order to clarify the mechanism of notable action of pituitary growth hormone on the growth of c...

The successful cultivation of vaccine virus in a medium consisting of minced chick embryo tissue suspended in Tyrode's solution and the use of this virus by means of dermal inoculation for Jennerian prophylaxis in man have been described in previous communications (1, 2). A continuation of investigations of culture vaccine virus has rendered possible at this time a statement regarding the desir...