Biomedical subjects

M Azuma

Publications and source records attributed to M Azuma.

At least 433 records · Page 24Linked to original sources

PubMed1976

A glass-insulated "Elgiloy" microelectrode for recording unit activity in chronic monkey experiments.

A glass-coated microelectrode made of a stiff cobalt--nickel alloy is described. The thickness of the glass coating and the length of the uninsulated tip can be varied as desired. The electrode is stiff enough to insert through the relatively tough dura of the monkey in chronic experiments. Further, the recording site can be marked by electrolytic deposition of iron and the Prussian blue reaction.

Alloys↗

PubMed1976

Viral factors required for interferon induction by Newcastle disease virus in mouse macrophages and chicken embryo cells.

The triggering mechanism for interferon synthesis in mouse peritoneal macrophages and chick embryo (CE) cells by Newcastle disease virus (NDV) exposed to hydroxylamine or homologous antiserum was investigated in relation to the intracellular fate of these agents. Inactivation of NDV at 22 degrees C by I M-hydroxylamine proceeded with first-order kinetics, whereas the interferon-inducing capacity of hydroxylamine-treated virus in macrophages was unimpaired. In contrast to infective NDV, hydroxylamine-inactivated virus produced interferon in CE cells, and such a virus still had partial RNA-dependent RNA polymerase activity. Hydroxylamine-inactivated NDV was adsorbed to and uncoated in both normal and chloroquine diphosphate treated cells, but no viral double-stranded RNA was detected. Hydroxylamine treatment of virion-extracted RNA and neutralization of intact virions by antibody abolished the capacity of the virus to induce interferon. Infective as well as neutralized NDV interacted with macrophages to the same degree, but association between NDV and CE cells was prevented by antibody-coating. In macrophages, the RNA of neutralized NDV became more sensitive to RNase than RNA of infective NDV, but this process was inhibited in chloroquine diphosphate-treated cells. These results suggest that interferon induction by NDV involves components of the virion which are present up to the regular uncoating process.

Animals↗

PubMed1975

Circular dichroism of cephalopod rhodopsin and its intermediates in the bleaching and photoregeneration process.

In the bleaching process of cephalopod rhodopsin, a new intermediate was found in the conversion process from lumirhodopsin to metarhodopsin. This intermediate of octopus has an absorption peak at about 475 nm and has been named as M475. The circular dichroism value of M475 is too small to be evaluated. On the other hand, lumirhodopsin shows a negative CD at 470 nm, a positive CD at 350 nm and a large positive CD band with three peaks at 280, 287 and 295 nm. Such a large CD band in the ultraviolet region is not observed in rhodopsin, M475 and metarhodopsin. This CD seems to be mainly due to tryptophan and tyrosine residues restricted in free rotation in the protein moiety of lumirhodopsin. The intermediate in the photoregeneration process of cephalopod rhodopsin, P380, has a positive CD band at the main peak, 380 nm, and also a large positive CD band in the ultraviolet region like lumirhodopsin.

Animals↗

PubMed1975