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Biomedical subjects

J Maeda

Publications and source records attributed to J Maeda.

At least 145 records · Page 8Linked to original sources

Studies on avian infectious bronchitis virus (IBV). III. Interferon induction by and sensitivity to interferon of IBV.

The induction of interferon by avian infectious bronchitis virus (IBV) and the sensitivity of IBV to interferon were studied. The results of experiments with ten IBV strains are summarized as follows. 1. All the IBV strains tested induced interferon in chick embryo (CE) cells, chicken kidney (CK) cells and embryonated eggs. The Iowa-609 strain induced about 1000 units of interferon in CE cells while the Beaudette-42 strain induced about 200 units of interferon in embryonated eggs; the interferon titers induced by other strains usually ranged from 5 to 60 units. No IBV strain induced interferon in HeLa or BHK-21 cells. 2. IBV particles inactivated by ultraviolet irradiation or by heating lost their ability to induce interferon. 3. The properties of the interferon produced in the present study are similar to those of other interferons produced in chicken cells. 4. HeLa or BHK-21 cells did not acquire resistance to virus infection, after incubation with interferon produced in CE cells. On the other hand, CK cells acquired the same degree of resistance to virus infection as CE cells after incubation with interferon produced in CE cells. 5. All the IBV strains tested were sensitive to interferon in CK cells. The sensitivities of Massachusetts-41 and Holte strains to interferon were similar to that of vesicular stomatitis virus.

Animals↗

Mycobacterial antigens relating to experimental pulmonary cavity formation.

Lipid-protein mixtures were obtained from 2 strains of mycobacteria, and their cavity-forming activities were examined in rabbit lungs. The mixtures were separated into lipid and protein fractions by gel filtration on Sephadex LH-20 column. Neither lipid nor protein fraction alone had cavity-forming activity; however, restoration of the cavity-forming activity was observed by recombining the fractions. The activity was also reconstructed by combining the protein fraction with cell walls of bacille Calmette-Guérin. The protein fraction from Mycobacterium phlei was further separated into 2 fragments. The larger molecular fragment with a molecular weight of 10,000 daltons consisted of 60% protein and 40% carbohydrate and had cavity-forming activity in combination with the cell walls. The roles of lipid and protein of mycobacteria in cavity formation are discussed.

Animals↗

Isolation and biochemical activities of trehalose-6-monomycolate of Mycobacterium tuberculosis.

A monoester of trehalose linked at the 6-position with mycolic acids (trehalose-6-monomycolate) was isolated from the wax D fraction of virulent human Mycobacterium tuberculosis, and its biochemical action on host-cell mitochondria was studied. Trehalose-6-monomycolate showed a delayed toxicity for mice. The 50% lethal dose at 2 weeks was 452 mug. It induced in vitro a swelling of mouse liver mitochondria and uncoupled respiration and phosphorylation in the nicotinamide adenine dinucleotide pathway of the electron transport chain. The site of functional damage was located specifically at coupling site II. Mitochondrial adenosine triphosphatase was slightly stimulated by trehalose-6-monomycolate. These findings indicate that trehalose-6-monomycolate affects mitochondrial oxidative phosphorylation in a similar manner to, but to a lesser extent than, trehalose-6, 6'-dimycolate (cord factor) of M. tuberculosis.

Adenosine Triphosphatases↗