Search PubMed⌕ Search

Biomedical subjects

M Kono

Publications and source records attributed to M Kono.

At least 343 records · Page 19Linked to original sources
PubMed1980

Nuclear magnetic resonance spectrometric assay of beta-lactamase.

Beta-Lactam antibiotics and the crude enzyme were mixed in deuterium oxide and placed in a nuclear magnetic resonance tube. The change of the nuclear magnetic resonance spectrum during the enzymatic reaction was then analyzed to determine beta-lactamase activity. By using beta-lactam antibiotics such as penicillins, cephalosporins, and cephamycins as substrates, a comparison of the beta-lactamase activities was made between the nuclear magnetic resonance spectrometric assay and the iodometric assay. There was a close correlation between these two methods.

Escherichia coli↗
PubMed1979

Lymphographic classification of malignant lymphoma.

In an attempt to raise the diagnostic accuracy of lymphography in malignant lymphoma, especially in early stages, the disease were radiographically classified into 3 groups such as atypical, typical and advanced group mainly based on the lymphographic findings. The findings showed characteristic features corresponding to the stages of the disease. Atypical group showed the following findings: small filling defects, increased number of lymph node and visualization of the marginal sinus. The findings were regarded as those of early stages of malignant lymphoma.

Humans↗
PubMed1978

Blockade by N-methylhydroxylamine of activation of guanylate cyclase and elevations of guanosine 3',5'-monophosphate levels in nervous tissues.

Hydroxylamine and N-methylhydroxylamine prevented the activation of soluble guanylate cyclase by the endogenous activator as well as by nitroso compounds such as N-methyl-N'-nitro-N-nitrosoguanidine or nitroprusside, while other derivaties of hydroxylamine were ineffective. Hydroxylamine and N-methylhydroxylamine did not alter the basal guanylate cyclase activity of purified enzyme preparations. Kinetics analysis indicated that N-methylhydroxylamine competes with N-methyl-N'-nitro-N-nitrosoguanidine for guanylate cyclase. The activation of guanylate cyclase by N-methyl-N'-nitro-N-nitrosoguanidine and its inhibition by N-methylhydroxylamine were reversible reactions. These effects of N-methyl-N'-nitro-N-nitrosoguanidine and N-methylhydroxylamine were observed with guanylate cyclase from other tissues. N-Methylhydroxylamine prevented the increase of guanosine 3',5'-monophosphate (cyclic GMP) levels in cerebellar slices of guinea pig by N-methyl-N'-nitro-N-nitrosoguanidine, veratridine and adenosine, while the elevations of adenosine 3',5'-monophosphate by these agents were not effected. N-Methylhydroxylamine also blocked the increases of cyclic GMP levels by carbachol, prostaglandin E1 and N-methyl-N'-nitro-N-nitrosoguanidine in neuroblastoma N1E 115 cells. Thus N-methylhydroxylamine prevents the activation of guanylate cyclase and the increased synthesis of cyclic GMP in response to transmitters without blocking the synthesis of cyclic GMP via basal enzyme activity.

Animals↗