Phospholipides containing amino acids other than serine. I. Detection

In view of the widespread occurrence of the amino acid-containing lipides and the unique course of their metabolism during development of Drosophila, we have carried out extensive investigations concerned with their isolation and chemical nature. The present report is concerned primarily with techniques and procedures developed to insure removal of non-lipide contaminants from preparations of these lipides

Fine Structure of Changes Produced in Cultured Cells Sampled at Specified Intervals During a Single Growth Cycle of Polio Virus

Primary suspended cultures of rhesus monkey kidney cells were infected with poliomyelitis virus, type 1 (Brunhilde strain). The release of virus from these cells over a one-step growth curve was correlated with their change in fine structure, as seen in the electron microscope. Most of the cells were infected nearly simultaneously, and morphological changes developed in the cells were sufficiently synchronous to be classified into three stages. The earliest change (stage I) became visible at a time when virus release into the culture fluid begins, some 3 hours after adsorption. Accentuation of the abnormal characteristics soon occurs, at 4 to 7 hours after adsorption, and results in stage II. Stage III represents the appearance of cells after their rate of virus release had passed its maximum, and probably the abnormal morphology of these cells reflects non-specific physiological damage. There seems to be consistency between the previously described cellular changes as seen under the light microscope and the finer scale changes reported here. Cytoplasmic bodies, called U bodies, were seen in large number at the time when the virus release was the most rapid (stage II). While these bodies are not of proper size to be considered polio virus, they seem to be specifically related to the infection. No evidence was found for the presence of particles that could even be presumptively identified with those of polio virus

Immunochemical studies on human plasma lipoproteins

Some years ago, a series of human serum lipoproteins, distinguishable by their hydrated densities and lipid-protein ratios were recognized and isolated by ultracentrifugal techniques (1). Certain of these lipoproteins are invariably present in human serum and the concentrations of these and of others can be quantitatively correlated with disease (2). No difference in the lipoprotein distribution can be demonstrated between serum and plasma. The purpose of this investigation was to obtain information about the immunochemical specificity of some of the lipoproteins