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Biomedical subjects

H R MORGAN

Publications and source records attributed to H R MORGAN.

At least 37 records · Page 2Linked to original sources
PubMed1959

Studies on the hemolysis of red blood cells by mumps virus. IV. Quantitative study of changes in red blood cell lipides and of virus lipides.

Hemolysis of chicken red blood cells by mumps virus is associated with the release of sphingomyelin from the stromal lipoprotein and the destruction of 65 per cent of the sphingomyelin of the red cell stroma. However, the virus had no effect on isolated phosphatides extracted from the erythrocytes. The hemolytic action of the virus and changes in sphingomyelin content of the erythrocytes fail to occur at a pH of 6.0. The viral hemolysis of human erythrocytes is not associated with similar alterations in their content of sphingomyelin. The absence of lecithin from sheep erythrocytes, which are also lysed by mumps virus, is additional evidence that a viral lecithinase is not associated with the hemolytic property of mumps virus. Mumps virus concentrated from the amniotic fluid of viral infected chick embryos contains about 7 per cent phosphatide, 60 per cent of which is sphingomyelin.

Animals↗
PubMed1958

Latent viral infection of cells in tissue culture. VI. Role of amino acids, glutamine, and glucose in psittacosis virus propagation in L cells.

Mouse fibroblasts (L cells) fail to support the growth of psittacosis virus (6BC strain) if they are maintained on a medium containing only inorganic salts and glucose for 2 days prior to infection. Virus propagation can be stimulated by the addition of a synthetic medium containing amino acids, water-soluble vitamins, glutamine, glucose, and inorganic salts. By omitting single amino acids from the complete synthetic medium, tyrosine, threonine, methionine, isoleucine, phenylalanine, tryptophan, leucine, valine, and cysteine or cystine were found to be essential for stimulation, while lysine, arginine, histidine, hydroxyproline, proline, glutamic acid, aspartic acid, serine, alanine, and glycine were not essential. The cells on deficient media showed varying degrees of degenerative changes, but there was little correlation between ability to support psittacosis virus growth and morphologic condition of the cells. Glucose is also an essential component of the medium for viral growth, but the absence of glutamine had no effect on stimulation of virus propagation. L cell cultures maintained on media deficient in phenylalanine or tryptophan for 2 days before infection were also found to be incapable of supporting virus growth. The implications of this study in latent viral infections are discussed.

Amino Acids↗
PubMed1958

Studies of hemolysis of red blood cells by mumps virus. III. Alterations in lipoproteins of the red blood cell wall.

Evidence from microscopic studies indicates that hemolysis caused by the mumps virus hemolysin is a chemical type of hemolysis. Chromatographic analyses of the reaction mixture of erythrocytes and mumps virus following hemolysis indicate that hemolysis is not due to the action of a lecithinase A and that lysolecithin does not play a part in this process. The alteration of a component of the erythrocyte similar to sphingomyelin suggests that some of the phosphatides other than lecithin may be either directly or indirectly affected in the process of hemolysis of red blood cells by the mumps virus.

Cell Death↗
PubMed1957

Latent viral infection of cells in tissue culture. IV. Latent infection of L cells with psittacosis virus.

By maintaining L cells in a balanced salt solution of inorganic salts and glucose (BSS) for 2 days or more, they are rendered incapable of supporting the growth of psittacosis virus (6BC), though it infects such cells and is present intracellularly for as long as 3 days in a non-infectious phase. The addition of an enriched medium to such a culture of cells at any time up to 4 days after infection results in the appearance of infectious virus within these cells, which multiplies and is released from the cells, providing the entire period of exposure of such cells to the BSS does not exceed 6 days, following which the cells die. A latent infection with psittacosis virus in a non-infectious phase has been established in a pure line of cells which possess properties of malignancy.

Chlamydophila psittaci↗
PubMed1957

Studies of delayed hypersensitivity in vitro. II. Delayed hypersensitivity in experimental mumps virus infections.

Guinea pigs experimentally infected with mumps virus develop a delayed, hypersensitive skin reaction following the intradermal injection of heat-inactivated mumps virus. This in vivo hypersensitivity is accompanied by a state of cellular hypersensitivity which can be demonstrated in vitro by the addition of mumps viral antigen to cultures of splenic macrophages, following which they become less motile and undergo lysis. These observations support the hypothesis that the state of hypersensitivity which develops early in mumps virus infections may have a role in the pathogenesis of the disease.

Animals↗