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Biomedical subjects

M Nishijima

Publications and source records attributed to M Nishijima.

At least 253 records · Page 14Linked to original sources
PubMed1982

New approach to regional anticoagulation in hemodialysis using gabexate mesilate (FOY).

Gabexate mesilate (FOY), a synthetic serine proteinase inhibitor, prevented and controlled bleeding during hemodialysis of 3 patients with active bleeding sites and/or hemorrhagic tendencies. The effectiveness of regional anticoagulation was evaluated by activated coagulation time (ACT). The ACTs of blood sampled from the outlet of dialyzer were significantly prolonged; however, systemic ACTs were almost normal. ACTs immediately after dialysis were not prolonged compared with those before dialysis. In 1 patients, renal function was improved after dialysis. No harmful side effects of FOY were observed. We consider FOY to be superior to other drugs for hemodialysis in that: (1) it can provide sufficient regional anticoagulation; (2) it has a very short half-life and need not be antagonized after dialysis; and (3) it can be used in patients with sepsis and/or disseminated intravascular coagulation (DIC) because it inhibits proteinase and also prevents platelet aggregation.

Aged↗
PubMed1981

Isolation of Escherichia coli mutants with elevated levels of membrane enzymes. A trans-acting mutation controlling diglyceride kinase.

We have developed a rapid autoradiographic colony assay for detecting mutants with elevated levels of certain biosynthetic enzymes. Four Escherichia coli strains in which the specific activity of the membrane enzyme diglyceride kinase is increased 5-10-fold have been obtained with this approach. The mutant kinase has the same thermal denaturation profile and subcellular localization as the wild type. Five other membrane enzymes involved in phospholipid bilayer assembly are unaffected. In one of these strains (GK-1) the mutation (dgkR-1) responsible for the elevated kinase has been mapped at a new site near minute 92, while the previously identified structural gene (dgk) lies near minute 90. When the structural gene for the kinase (dgk) is cloned on a multi-copy vector-like ColE1, the kinase can be overproduced 5-10-fold on the basis of gene dosage (Lightner, V. A., Larson, T. J., Tailleur, P., Kantor, G. D., Raetz, C. R. H., Bell, R. M., and Modrich, P. (1980) J. Biol. Chem. 255, 9413-9420). Introduction of such hybrid plasmids into a mutant harboring dgkR-1 leads to a multiplicative (rather than additive) effect, resulting in specific activities of diglyceride kinase that are 35-75-fold higher than normal. These results show that dgkR-1 is a trans-acting mutation and suggest the existence of novel regulatory proteins (or metabolites) that direct the expression of certain membrane enzymes.

Cell Membrane↗
PubMed1981

Incorporation and metabolism of 2-acyl lysophospholipids by Escherichia coli.

The incorporation of 2-acyl lysophospholipids into Escherichia coli, and their metabolism were studied. 2-[14C]Acyl lysophosphatidylethanolamine could penetrate into E. coli cells and was mainly incorporated into phosphatidylethanolamine. 2-Acyl lysophosphatidylethanolamine was partially degraded, but some of it was incorporated into membrane phospholipids by acylation. 2-Acyl lysophosphatidylcholine also entered cells and was acylated to phosphatidylcholine. The acylation of 2-acyl lysophospholipid by the envelope fraction was also studied. Fatty acids were incorporated into 2-acyl lysophospholipids by the envelope fraction in the presence of ATP and Mg2+, and the incorporation was stimulated by acyl carrier protein, but not by coenzyme A. No acylation was observed with acyl coenzyme A as acyl donor. The acylation activities of the inner and outer membranes were examined. Pathways for degradation and modification of membrane phospholipids in E. coli are proposed.

Carbon Radioisotopes↗
PubMed1981

Two interacting mutations causing temperature-sensitive phosphatidylglycerol synthesis in Escherichia coli membranes.

A conditionally lethal mutant of Escherichia coli lacking phosphatidylglycerol in vivo at 42 degrees C has been previously isolated by two-stage mutagenesis (M. Nishijima and C. R. H. Raetz, J. Biol. Chem. 254:7837-7844, 1979). In the first step (designated pgsA444) the phosphatidylglycerophosphate synthetase is partially inactivated, but the resulting strain continues to make about two-thirds of the normal level of phosphatidylglycerol and is not temperature sensitive. The second lesion, termed pgsB1, causes temperature-sensitive growth and phosphatidylglycerol synthesis in strains harboring pgsA444. The pgsA locus appears to be the structural gene for the synthetase and maps near min 42. In the present study we mapped the pgsB1 mutation and characterized its interaction with pgsA444 by genetic and biochemical methods. Unexpectedly, pgsB1 was not a second lesion in the pgsA structural gene, but rather mapped at a distinct site near minute 4. P1 vir-mediated contransduction suggested the gene order pantonA-dapD-pgsB-dnaE (clockwise). Independent evidence for the genetic mapping was provided by the identification of two hybrid ColE1 plasmids (pLC26-43 and pLC34-20. L. Clarke and J. Carbon, Cell 9:91-99, 1976) which both carry pgsB+ and dnaE+. Introduction of either the pgsA+ or the pgsB+ gene (via episomes, hybrid plasmids or P1 vir transduction) suppressed the temperature sensitivity of the double mutant (pgsA444 pgsB1) and restored normal levels of phosphatidylglycerol at 42 degrees C. In addition, strains with the pgsA+ pgsB1 genotype produced a novel lipid (X) at all temperatures, whereas the double mutant (pgsA444 pgsB1) contained two unusual lipids (X and Y) after 3 h at 42 degrees C. Both X and Y are precursors of lipopolysaccharide, and introduction of pgsB+ into the double mutant caused the disappearance of X and Y. Although the biochemical basis of the pgsB1 lesion is unknown, its existence suggests a previously unrecognized link between lipopolysaccharide and phosphatidylglycerol syntheses in E. coli.

Chromosome Mapping↗
PubMed1981

[FHR long term variability under various obstetrics analgesia (author's transl)].

Changes of FHR long term variability (LTV) were studied in four groups of patients under different types of analgesia. The LTV was evaluated according to our visual criteria in each episode of more than one minute of duration on baseline fetal heart rate level between contractions. In the balanced anesthesia group incidence of the episodes with LTV decreased significantly after the administration of Diazepam and Methoxyflurane (64%-30%), further decreasing after the injection of Pethilorfan, but it increased to some degree within 20 min. before delivery. In the epidural group the change of LTV was mild, but the LTV decreased after each administration of 0.25% Bupivacaine (58%-44%-36%). It is also showed mild increase within 20 min. before delivery. Loss of variability was persistently noted until the end of labor from 20-40 min. after the administration of Diazepam and Pentazocine in the modified NLA group. The change in paracervical block group was quite different from the other groups. The incidence of episodes with LTV was increased after the injection of 1% Lidocaine Hydrochloride (35%-41%). There was no significant different of blood gas and acid-base balance among four types of analgesia.

Anesthesia, Epidural↗
PubMed1981

Simultaneous detection of several Fusarium mycotoxins in cereals, grains, and foodstuffs.

A systematic method is described for the simultaneous determination of Fusarium mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, diacetoxyscirpenol, neosolaniol, T-2 toxin, HT-2 toxin, butenolide, moniliformin, and zearalenone) in cereals, grains, and foodstuffs. Mycotoxins were extracted with aqueous methanol and purified by a 2-step chromatographic procedure using Amberlite XAD-4 and Florisil columns. The column eluates were concentrated and spotted on a thin layer chromatographic (TLC) plate which was then developed in CHCL3-methanol (93 + 7) and toluene-acetone-methanol (5 + 3 + 2). Each mycotoxin was quantitated by gas chromatography (GC) and TLC densitometry. The minimum detectable concentrations (microgram/kg) in various test materials were: nivalenol, deoxynivalenol, and fusarenon-x, 2.0; diacetoxyscirpenol, neosolaniol, T-2 toxin, and HT-2 toxin, 80; zearalenone, 10; butenolide, 30; and moniliformin, 50. Recoveries of the mycotoxins added to various cereal samples at 1.0-2.0 microgram/g were greater than 71% and averaged 85%.

Chromatography↗