PubMed Health⌕ Search

Biomedical subjects

M Iinuma

Publications and source records attributed to M Iinuma.

At least 109 records · Page 6Linked to original sources

Cross-linking of Newcastle disease virus (NDV) proteins.

The proxomity and spatial relationships of the structural proteins of Newcastle disease virus (NDV) were studied by chemical cross-linking with a series of imidoesters. When the virions were reacted by the cross-linker with a distance 6.1A or longer between the functional groups and analyzed by polyacrylamide gel electrophoresis, remarkable changes were observed in the migration patterns of the viral proteins. The most striking one was the extensive decrease in the intensity of the M protein band, and although not so strikingly, glycoprotein and nucleocapsid protein bands were reduced significantly. Instead, several protein complexes appeared at and near the top of the gels. The protein complexes formed by a reversible cross-linker, dimethyl-3,3'-dithiobispropionimidate (DTBP), were analyzed by two dimensional electrophoresis; the complexes on the first-dimension cylindrical gels were cleaved by reduction with 2-mercaptoethanol and electrophoresed laterally on the second-dimension slab gels. The results indicated that homodimers of glycoprotein, nucleocapsid protein and M protein were generated under the condition of the most gentle cross-linking employed. At the same time, however, trimer and higher homopolymers of M protein were already detectable. Under the more extensive conditions, the bulk of M protein was cross-linked to form a large protein complex with very high molecular weight. Further, small but significant amounts of glycoprotein and nucleocapsid protein were always detected in this complex. These results suggest that M protein may be present in the virion in close enough proximity to interact with each other and may further have some interactions with glycoprotein and nucleocapsid protein. On the basis of these findings possible roles of M protein in virus assembly were discussed.

Dimethyl Adipimidate↗

Restitution of hemagglutinating activity to spikeless particles of HVJ (Sendai virus) by glycoprotein components of Newcastle disease virus.

Spikeless particles of HVJ (Sendai virus) lacking in hemagglutinating (HA) activity were obtained by enzymatic digestion of virions with trypsin followed by centrifugation through a sucrose gradient. When they were mixed with glycoprotein components of Newcastle disease virus (NDV) obtained by treatment of purified virions with deoxycholate (DOC), the mixture showed hemagglutination reaction, which was inhibited by anti-NDV serum, but not by anti-HVJ serum. Sedimentation profile of the HA active agents was then examined by centrifugation of the mixture of spikeless particles of HVJ (labeled with 3H-uridine) and glycoproteins of NDV (labeled with 14C-amino acid mixture). The results showed that the peak of HA activity had both of the radioactivities, and that the sedimentation rate of the HA was faster than that of spikeless HVJ but slower than that of intact HVJ. Electron micrographs of such HA active structures showed that they were morphologically closely similar to intact virion of HVJ, although they had neither hemolytic activity nor infectivity. The mixture of spikeless HVJ and glycoproteins of HVJ or NDV which were removed from virions by proteolytic enzymes, on the other hand, did not show any detectable hemagglutinating activity.

Deoxycholic Acid↗

Intracellular development of membrane protein of influenza virus.

The intracellular development of membrane protein (MP) of influenza A virus was investigated by immunofluorescent staining. Monospecific antiserum was prepared by immunizing rabbits with MP eluted from SDS-polyacrylamide gels of SDS-disrupted NWS virions. In the productive infection in clone 1-5C-4 cells, MP antigen was first detected over the whole cell at 4 hr after infection, concomitantly with the appearance of hemagglutinin (HA) antigen in the cytoplasm, and bright nuclear fluorescence was then observed. Nucleoprotein (NP) antigen was detected in the nucleus prior to the appearance of fluorescence of MP antigen and thereafter the cytoplasmic fluorescence developed. Late in infection, all of these three antigens were observed predominantly in the cytoplasm with stronger fluorescence at the cell surface. Essentially similar findings were obtained in the abortive infections in L cells and BHK cells. The above results suggest that the membrane protein of influenza A virus is present in the nucleus as well as in the cytoplasm of infected cells.

Cell Line↗

Metabolic fate of carteolol hydrochloride, (OPC-1085) VIII, a new beta-adrenergic blocking agent. Pharmacokinetic studies of carteolol in man.

The pharmacokinetics of 5-(3-tert.-butylamino-2-hydroxy)-propoxy-3,4-dihydrocarbostyril hydrochloride (carteolol hydrochloride, OPC-1085) have been investigated in man following single or repetitive oral administration. The plasma half-lives. The plasma half-lives of carteolol at single doses of 10, 15 and 30 mg were 5.4, 5.5 and 5.0 h, respectively. The amounts of carteolol excreted into urine within 24 h at the same dose levels accounted for 64, 70 and 76% of the respective doses. The half-lives obtained by the Sigmaminus method were 5.6, 5.6 and 5.4 h, respectively, being essentially consistent with the aforementioned plasma half-lives of carteolol after administration at 15 mg daily for 7 successive days were determined to be 5.54 h on the 1st day and 6.91 h on the 7th day, displaying the increase in half-life value with the repetitive dosing. While, the predicted value determined using the experimental value on the 1st day agreed with the experimental value on the 7th day. Furthermore, the amounts of carteolol excreted in the urine were not significantly different between the 1st and 7th days. The 7-day repetitive administration with carteolol brought about the steady state of plasma levels. It was concluded from these results that carteolol has little ability to accumulate in man.

Adrenergic beta-Antagonists↗

Recovery of infectious proviral DNA from mammalian cells infected with respiratory syncytial virus.

The DNA fraction from a line of bovine embryonic kidney cells originally exposed as primary cultures several months earlier to a temperature-sensitive (ts) mutant of respiratory syncytial (RS) virus could be used to transfect human HEp-2 cells with the production of infectious RS virus. The DNA donor cells, designated BEK/RS ts, retained their healthy fibroblastic appearance during continuous cultivation at a temperature (39 degrees) restrictive for growth of the original infecting mutant and showed no evidence for RS virus replication or viral antigen synthesis when directly examined for these activities by conventional methods. The infectious property of the DNA from BEK/RS ts cells was abolished by exposure of the nucleic acid preparation to DNase (but not RNase) or by pretreatment of recipient HEp-2 cells with actinomycin D or mitomycin C. The latter drug treatments substantially enhanced the replication of infecting wild-type RS virus in HEp-2 cells. Viral isolates derived from the progeny of a DNA transfection included clones possessing several genetic markers of the RS ts mutant originally used to infect BEK/RS ts cells and other virus clones that appeared to be either hybrid or wild-type for phenotypic properties such as their temperature sensitivity. An infectious proviral DNA was also detected in a line of virogenic HEp-2 cells (HEp-2/RS) persistently infected with respiratory syncytial virus after exposure to the wild-type strain 2 years earlier.

Cell Line↗

Inhibition of virus growth by ouabain: effect of ouabain on the growth of HVJ in chick embryo cells.

The effect of ouabain (g-strophanthin), a cardiac glycoside, on the growth of several enveloped viruses was examined. It was found that the growth of HVJ (Sendai virus) in chick embryo cells was markedly inhibited by the drug at a concentration as low as 5 x 10(-5)m. A virus-inhibitory concentration of ouabain did not cause morphological changes in uninfected cells, nor did it have the capacity to inactivate virus infectivity. Ouabain interfered with the intracellular synthesis of viral macromolecules. Although viral ribonucleic acid and viral antigens were synthesized by the ouabain-treated cells, the rate of synthesis was slower, and the total amounts of these macromolecules were smaller than those in the untreated control cells. It is suggested that ouabain inhibits the function of membrane-bound Na, K-adenosine triphosphatase of the chick embryo cells and thus prevents accumulation of K ion in them. Accumulation of intracellular K ion to a certain level would be needed for events of exponential growth of virus to proceed, and ouabain might inhibit this step by preventing such accumulation of K ion. This view was supported by the finding that the concentration of K ion in the HVJ-infected cells was rapidly reduced by the treatment with ouabain, and that, when the ouabain-treated culture was shifted to a medium containing a higher concentration of K ion than normal medium, virus production started in parallel with the increase of intracellular K ion. The fact that the concentration of K ion in BHK-21 cells, which support virus growth in the presence of ouabain, is not reduced by the treatment with the drug also suggested this possibility.

Animals↗