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Biomedical subjects

K Kishida

Publications and source records attributed to K Kishida.

At least 109 records · Page 6Linked to original sources
PubMed1982

Importance of the antigen-binding valency and the nature of the cross-linking bond in ricin A-chain conjugates with antibody.

As a continuation of our work on toxin A-chain conjugates with antitumor antibodies for selective delivery of the toxin to the target cells, four ricin A-chain conjugates were prepared by linking A-chain to Fab' or F(ab')2 of rabbit IgG against L1210 with or without employing a cross-linking agent, N,N'-o-phenylenedimaleimide (PDM), N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) or N-succinimidyl m-(N-maleimido)benzoate (SMB), and the effects of antigen-binding valency and of the nature of the cross-linking bond on their in vitro cytotoxicity were studied. The relative potencies of the conjugates in terms of IC94's were as follows: F(ab')2-SPDP-A-chain, 100; Fab'-S-S-A-chain, 21; F(ab')2-SMB-A-chain, 1.3; Fab'-PDM-A-chain 0.38. Among the four conjugates, F(ab')2-SPDP-A-chain and Fab'-S-S-A-chain can be cleaved into the homing and the cytotoxic components with 2 mM 2-mercaptoethanol. These results suggest that divalency in antigen-binding and susceptibility of the cross-linking bond to cleavage by mercapto reagent are desirable for high potency. Protein synthesis in a cell-free system of rabbit reticulocyte lysate was inhibited by Fab'-S-S-A-chain and by Fab'-PDM-A-chain as effectively as by free A-chain, indicating that the liberation of A-chain is not important, at least on ribosomes, but it is important for the A-chain to reach a ribosome after binding of the conjugates to the cell-surface.

Animals↗
PubMed1981

Relationship between methylation of adenine near the 3' end of 16-S ribosomal RNA and the activity of 30-S ribosomal subunits.

The relationship between methylation of adenine near the 3' end of 16-S ribosomal RNA and the activity of 30-S ribosomal subunits has been studied using 30-S subunits from kasugamycin-sensitive and kasugamycin-resistant bacteria. Analysis of the proteins of 30-S subunits by gel electrophoresis showed that the content of protein S1 in 30-S subunits from a kasugamycin-resistant strain was smaller than that in 30-S subunits from the parent strain. Although polyphenylalanine-synthetic activity of 30-S subunits from a kasugamycin-resistant strain previously methylated by a methylase purified from Escherichia Q13 was nearly equal to that of untreated 30-S subunits, both phenylalanine-synthetic activity and the content of protein S1 in the 30-S particles reconstituted from 23-S core particles and split proteins from the kasugamycin-resistant strain increased by prior methylation of 23-S core particles by the methylase. These results suggest that methylation of adenine near the 3' end of 16-S rRNA induces an increase of polypeptide-synthetic activity by the acceleration of binding of protein S1 to S1-depleted 30-S subunits.

Adenine↗
PubMed1981

Decrease in the S1 protein of 30-S ribosomal subunits in polyamine-requiring mutants of Escherichia coli grown in the absence of polyamines.

The reason for the decrease of polypeptide-synthetic activity of 30-S ribosomal subunits obtained from two polyamine-requiring mutants of Escherichia coli, grown in the absence of polyamines, has been studied by analyzing the total and split proteins of 30-S subunits by disc gel and slab gel electrophoresis. It was concluded that the decrease of S1 protein in 30-S subunits was responsible for the decrease of polypeptide synthesis in polyamine-requiring mutants of E. coli grown in the absence of polyamines.

Electrophoresis, Polyacrylamide Gel↗
PubMed1979

Defect in the split proteins of 30-S ribosomal subunits and under-methylation of 16-S ribosomal RNA in a polyamine-requiring mutant of Escherichia coli grown in the absence of polyamines.

Polyphenylalanine synthesis was carried out with Escherichia coli Q13 50-S ribosomal subunits and reconstituted 30-S particles containing different combinations of 23-S core particles and 30-S subunit split proteins obtained from a polyamine-requiring mutant of E. coli during its growth in the presence or absence of putrescine. It was concluded that the defect in the amount of some kinds of 30-S subunit split proteins was responsible for the decrease of polypeptide synthesis in a polyamine-requiring mutant of E. coli grown in the absence of polyamines. The methylation of 16-S RNA during growth in the absence of putrescine was decreased, while the degree of methylation of 23-S RNA did not change significantly. The decrease in methylation of 16-S RNA in the absence of putrescine was due mainly to a decrease of methylation of adenine. The relationship between the decrease of polypeptide synthetic activity of 30-S ribosomal subunits obtained from a polyamine-requiring mutant of E. coli grown in the absence of polyamines and the decrease of methylation of 16-S RNA is discussed.

Aminoglycosides↗
PubMed1979

[Primary interhemispheric subdural abscess--case report (author's transl)].

A case of primary interhemispheric subdural abscess was reported, which was not accompanied by abscess formation in other places such as subdural spaces of the convexity or in the brain. A 13-year-old school boy was admitted with 8 days' history of fever, headache and progressive weakness of the left lower extremity. Prior to admission he developed 2 spells of jacksonian seizure initiating from the left leg. Right carotid angiography was performed on admission and separation of the pericallosal and callosomarginal arteries with small avascular area was shown indicating possible abscess formation in the interhemispheric fissure. There was no evidence of purulent infection in the laboratory findings including the CSF and EEG showed diffuse slow wave discharge, more in the right frontocentral leads. He was placed on the vigorous treatment with antibiotics and steroids, and one month later the left lower weakness as well as the EEG abnormality showed some improvement. However, the separation of the anterior cerebral arterial branches became more prominent and formed a lens shaped avascular area, although the pericallosal artery was in the midline. A diagnosis of interhemispheric subdural abscess was made and was confirmed by surgery. Patient showed progressive recovery of the left lower paralysis, and the abscess was totally collapsed in the repeated angiographic follow-up study. Angiographic characteristics of the interhemispheric subdural abscess were described and particular emphasis was placed on the peculiar neurological symptoms referring to the previous reports in the literature.

Adolescent↗