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Biomedical subjects

M Ikemoto

Publications and source records attributed to M Ikemoto.

At least 19 recordsLinked to original sources
PubMed1995

Decrease in CRE binding activity by chronic morphine administration in mouse brain.

Recent studies have suggested that opiate addiction is associated with transcriptional changes. We developed a novel method, in situ DNA-protein binding (ISDB), for investigating the distribution and changes of DNA binding activity of transcription factors in the brain. Using this method, we found that cAMP response element (CRE) binding activity was decreased by chronic morphine treatment in specific regions including the amygdala complex, thalamus, cerebral cortex and hypothalamus in mouse brain. This effect persisted for at least 14 days after the cessation of morphine. These data suggest that chronic morphine treatment elicits a long-term change in cAMP-mediated gene expression in the brain.

Animals↗
PubMed1994

Modulation by chronic morphine administration of single-stranded cAMP response element (ssCRE) binding proteins in the mouse cerebellum.

The development of opiate tolerance and dependence are thought to be associated with gene expression. Our previous studies have shown that the binding activity of nuclear factors to a single-stranded oligo-DNA containing cAMP response element (ssCRE) is altered by long term treatment with morphine in cultured neuronal cells. In the present experiments, the effects of acute and chronic treatments with morphine on the binding of nuclear proteins to single- and double-stranded oligo-DNAs of the cAMP response element were studied in the mouse brains by using gel shift assay. The activity of single-stranded CRE binding proteins (ssCRE-BP) was decreased by chronic morphine treatment to about 40% of control in the cerebellum. The effect of chronic morphine treatment on the binding activity persisted for at least 2 weeks after morphine withdrawal. The activity of double-stranded CRE binding proteins was also detected in the cerebellum, but it was insensitive to the morphine treatment. The activity of ssCRE-BP was also decreased by acute morphine treatment in 5 h, but it returned to control level in 24 h. These data suggest that the change of ssCRE-BP can be involved in the development of tolerance and dependence.

Animals↗
PubMed1994

Immunosuppression by lymphokine-activated murine killer cell line with B-lymphoblast-lytic activity in vitro.

The in vitro immunosuppressive effect caused by a murine lymphokine-activated killer cell line with B-lymphoblast-lytic activity was studied. The cloned cells (named BC-1.10, phenotype Thy 1.2+, LFA-1+, TCR-alpha beta-, TCR-gamma delta-, Fc gamma RII-, CD2-, CD3 epsilon-, CD4-, CD8- and express mRNA of zeta chain) suppressed LPS-induced Ig synthesis by B lymphoblasts previously stimulated with LPS. Phase-contrast microscopy indicated disappearance of B lymphoblasts at 24 h after the addition of BC-1.10 cells. This suppressive effect was reduced when BC-1.10 cells were pretreated with anti-LFA-1 mAb, which inhibits cytotoxicity of this clone. These data suggest that the immunosuppressive effect of BC-1.10 is due to an elimination of B lymphoblasts, and that one of the physiological functions of lymphokine-activated killer (LAK) cells, which are induced as a consequence of immune reactions, might be immunosuppression.

Animals↗
PubMed1994

[Involvement of gene expression in drug tolerance and dependence].

The development of drug tolerance and dependence are thought to be associated with gene expression. Our studies showed that the binding activity of nuclear factors to several DNA sequences is altered by long-term treatment with methamphetamine, cocaine and morphine: 1) the binding activity of AP-1 increased markedly in the mouse brain after administration of methamphetamine and cocaine, 2) CRE-binding activity was decreased by chronic morphine treatment in the amygdala complex, cerebral cortex and hypothalamus of the mouse brain, and 3) the binding activity of single-stranded CRE binding proteins was decreased by chronic morphine treatment in the mouse cerebellum. These data suggest that the changes of DNA binding proteins can be involved in the development of drug tolerance and dependence.

Amphetamine↗
PubMed1994

[A case of Wernicke's encephalopathy which accompanied a passing blindness].

The case of a chronic alcoholic patient with Wernicke's encephalopathy accompanied by passing blindness is reported and the alcoholic amblyopia is discussed in this study. The patient was a 39 year-old male who had been a heavy drinker for 13 years, and was habitually inebriated for the last one year. Disturbance of consciousness ataxia of gait, nystagmus and blindness were manifested on admission. Decreased level of serum vitamin B1 was also recognized at admission. The symptoms diminished from about a month after admission except for horizontal nystagmus. Since the patient had racket-like scotoma in his central visual field, his blindness was thought to be alcoholic amblyopia. Although alcohol dependence is associated with many physical disabilities, there are few reports about Wernicke's encephalopathy with alcoholic amblyopia. This case demonstrates the importance of careful physical examination for understanding alcohol-related disabilities and alcohol dependence.

Adult↗
PubMed1993

PC-766B, a new macrolide antibiotic produced by Nocardia brasiliensis. II. Isolation, physico-chemical properties and structure elucidation.

A new macrolide antibiotic, PC-766B, was isolated from the cells of Nocardia brasiliensis SC-4710 by acetone extraction, and purified by gel filtration, silica gel chromatography, HPLC and TLC. The structure of PC-766B was determined by NMR spectral analysis to be a new class of the hygrolidin family antibiotics. PC-766B had a 16-membered macrocyclic lactone ring, a 6-membered hemiketal ring and a 2-deoxy-D-rhamnose moiety. DL-alpha-Tocopherol, known as an antioxidant agent, significantly improved the stability of PC-766B and prevented the decomposition of PC-766B during the storage of the antibiotic.

Anti-Bacterial Agents↗
PubMed1993

Effects of prostaglandin E1 on the production of IgM and IgG class anti-dsDNA antibodies in NZB/W F1 mice.

OBJECTIVE: To investigate the effects of prostaglandin E1 (PGE1) on IgM and IgG class anti-dsDNA antibody production by young and aged female New Zealand black/white (NZB/W) F1 mouse spleen cells in vitro. METHODS: Whole cells or B cells from NZB/W F1 mouse spleen cells were cultured with lipopolysaccharide (LPS) in the absence or presence of graded concentrations of PGE1 for 1 to 5 days. After cultures, the supernatants were collected and assayed for released IgM and IgG class anti-dsDNA antibodies by enzyme-linked immunosorbent assay. RESULTS: Young (3-month-old) mouse spleen cells produced similar levels of IgM class anti-dsDNA antibodies, while these cells produced considerably low levels of IgG class anti-dsDNA antibodies compared to aged (6-month-old) mouse spleen cells when stimulated with LPS. PGE1 suppressed the production of IgM class anti-dsDNA antibodies by about 50% at a concentration of 10(-6) M in both young and aged mouse spleen cell cultures. On the other hand, the production of IgG class anti-dsDNA antibodies was resistant to the inhibitory effects of PGE1. CONCLUSION: Our data suggest that PGE1 is effective in inhibiting the antibody synthesis by B cells precommitted to IgM class anti-dsDNA antibody production, but the production of IgG class anti-dsDNA antibody by memory B cells present in young and aged mice is resistant to the inhibitory effects of PGE1.

Aging↗
PubMed1993

Enzyme immunoassay of liver-type arginase and its potential clinical application.

We developed an efficient enzyme-linked immunosorbent assay (ELISA) system for measurement of human liver-type arginase in serum. A conjugate of the Fab' fragment of anti-human liver (recombinant) arginase IgG and horseradish peroxidase was used as the second antibody. This assay is highly specific, sensitive, and reproducible, enabling us to detect arginase at concentrations as low as several micrograms per liter without any prior processing of serum. The reaction is linear up to 200 micrograms/L. The arginase concentration in serum, as determined by this method, increased markedly and temporarily at the time of surgical operation or later injury to the liver. The increase was accompanied or followed by increases in serum concentrations of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, suggesting that the arginase emerged from damaged hepatocytes. In view of a limited tissue distribution of liver-type arginase, our ELISA system may be useful in diagnosis of various hepatic disorders as well as follow-up of postoperative conditions of patients.

Adolescent↗
PubMed1992

In situ DNA-protein binding: a novel method for detecting DNA-binding activity of transcription factor in brain.

A novel method, in situ DNA-protein binding (in situ DPB), was developed to detect the distribution and DNA-binding activity of AP-1 and Sp1 binding proteins in situ. The regional distribution of AP-1 binding protein in mouse brain was different from that of Sp1. Antibody against the DNA-binding domain of Jun protein markedly reduced the AP-1 but not the Sp1 binding activity. The binding activity of AP-1 probe increased markedly in the brain after administration of methamphetamine. These results suggest that the in situ DPB is convenient and sensitive for detecting the distribution and the DNA-binding activity of transcription factors in situ.

Animals↗
PubMed1992

[Liver transplantation and functions of the graft liver].

Partial liver transplantation from living donors is a new surgical operation on patients in the final stage of liver dysfunction. Among about 90 operations so far done in the world, 34 were performed at the Second Department of Surgery in Kyoto University Hospital (as of June, 1992). Good but limited cooperation between surgeons and clinical laboratories has contributed to saving the lives of as many as 28 patients. Analysis of laboratory data and clinical course of patients indicated that pre-, mid-, and postoperational examinations of blood flow through the graft liver by the use of Doppler echography and the monitoring of the liver capacity to generate ATP by the aid of the arterial ketone body ratio are most important for early detection of dysfunctioning liver grafts. An unusually high incidence of the transient hyperphosphatasemia-like elevation of alkaline phosphatase and a frequent appearance of liver-type arginase in serum during the postoperative stage seemed to indicate some pathological changes of the liver.

Adolescent↗
PubMed1991

Effects of chronic exposure of NG108-15 cells to morphine or ethanol on binding of nuclear factors to cAMP-response element.

The gel retardation assay with a single-stranded oligo-DNA of cAMP-response element (CRE) in a somatostatin promoter region was selected to examine the possibility of transcriptional regulation of cAMP-inducible genes by chronic morphine or ethanol treatment of NG108-15 cells. When the nuclear extracts from the cells treated with morphine (50 microM) or ethanol (100 mM) for several days were assayed, the amount of DNA-protein complex was decreased about 30-40% compared to that of the control. The decreased complex was recovered by 1-2 days after withdrawal of the drugs. Treatment of the cells with these drugs for 1 h did not change the amount of the DNA-protein complex. Thus, changes in CRE-binding proteins from the cells treated chronically with morphine or ethanol suggest that these drugs can modulate the expression of cAMP-inducible genes through which tolerance and dependence may develop.

Animals↗
PubMed1991

Absence of erythrocyte arginase protein in Japanese patients with hyperargininemia.

In Japan, hyperargininemia has been reported in only 5 unrelated families and four patients are alive at present. In this study we examined arginase protein in erythrocytes of these Japanese patients using two analytical methods of immunoblotting and two-dimensional gel electrophoresis. Immunoblotting study with anti-E. coli-expressed human liver arginase rabbit IgG revealed lack of cross-reacting materials in the erythrocyte lysates from these patients. On two-dimensional gels, arginase protein was detected in any control subject, but it was completely absent in all the patients studied. These results suggest that either arginase protein in erythrocytes is not produced or it is structurally labile in these patients.

Adult↗
PubMed1991

Interleukin-2-activated murine cell lines with macrophage- and B-lymphoblast-lytic activity.

Interleukin-2 (IL-2)-activated murine killer cell lines with macrophage- and B-lymphoblastic-lytic activity were established, and their target specificity, surface markers, recognition-related structures, and requirements for optimal cell growth were characterized. Sustained growth of IL-2-activated lymphocytes was supported by the combination of IL-2 and IL-4-enriched T cell conditioned medium (CM), but was not supported by IL-2 alone or the combination of IL-2 and IL-3-containing CM in the presence of macrophages (M phi). The established line required continuous contact with M phi to maintain anti-M phi cytolytic activity. Flow cytometric analysis showed that the original line isolated by the first cloning was Thyl+, CD4-, and weakly CD8+, FcR+. The majority of these cells were CD3+ and TCR-V beta 8+. From this line, the CD3+, TCR-V beta 8+ and CD3-, TCR-V beta 8- clones were isolated by subcloning. The former clone showed Thyl+, CD3+, CD4-, CD8-, TCR-V beta 8+, FcR(+)-phenotype, and the latter clone showed Thyl+, CD3-, CD4-, CD8-, TCR-V beta 8-, FcR- phenotype. The original line and subclones showed a similar target specificity and killed resident or thioglycollate (TG)-induced peritoneal M phi and B-lymphoblasts, but did not kill T-lymphoblasts. Allogeneic M phi, M phi-like cell line P388D1, and B cell hybridoma were sensitive, whereas fresh lymphocytes, T cell lymphoma BW5147, natural killer (NK)-sensitive YAC-1, and NK-resistant P815 tumor cells were resistant to lysis by these cytotoxic lines. The addition of anti-H-2 heteroserum, anti-MHC class 1, anti-MHC class II, anti-CD3, or anti-TCR-V beta 8 monoclonal antibody (mAb) to assay cultures did not inhibit the anti-M phi cytolysis by these killer cells. In addition, the CD3- TCR-V beta 8- clone killed M phi and B lymphoblasts better than the CD3+, TCR-V beta 8+ clone. These results suggest that cytotoxic lines established in this study do not use the T cell receptor (TCR) molecules to recognize target cells and the MHC molecules are not involved in recognition. Anti-LFA-1 mAb partially inhibited anti-M phi-lysis, suggesting that the cell contact between targets and effectors is important in cytolysis. Our present data suggest that the culture condition containing IL-2, IL-4, and M phi may support the continuous growth of non-MHC-restricted killer cells with relative target specificity against M phi and B-lymphoblasts.

Animals↗
PubMed1991

[Molecular mechanism of drug tolerance and dependence].

Morphine and ethanol drugs known to develop tolerance and dependence, induce changes in the adenylate cyclase system. Morphine inhibits the adenylate cyclase activity in NG108-15 cells and causes increases in adenylate cyclase synthesis and the down-regulation of opiate receptors in cells treated for several days. Chronic exposure of NG108-15 cells to ethanol also causes a decrease in the mRNA of the GTP-binding protein (Gs). These observations suggest the possibility that a group of genes is expressed in response to morphine or ethanol during the acquisition of tolerance and dependence. Recently, it has been reported that cAMP regulates a number of genes through a cAMP response element (CRE) in their promotor regions and that nuclear CRE-binding proteins bind specifically to the CRE to stimulate the transcription of cAMP-responsive genes. The gel shift assay with a single stranded oligo-DNA of CRE in a somatostatin promotor region was employed to examine the possibility of transcriptional regulation of cAMP-inducible genes by chronic morphine or ethanol treatment of NG108-15 cells. When the nuclear proteins from the cells treated with morphine or ethanol for several days were provided for the assay, the amounts of DNA-protein complex were decreased. The decreased complexes were recovered by 1-2 days after morphine withdrawal. The nuclear proteins were purified partially by a combination of chromatography on Q-Sepharose, Sephacryl S-300 and DNA affinity-Sepharose. Changes in CRE-binding proteins from the cells treated chronically with morphine or ethanol suggest that these drugs can modulate the expression of cAMP-inducible genes through which tolerance and dependence may develop.

Base Sequence↗
PubMed1990

Expression of human liver arginase in Escherichia coli. Purification and properties of the product.

Arginase is an enzyme that catalyses the hydrolysis of arginine to urea and ornithine. It is abundantly present in the liver of ureotelic animals (i.e. those whose excretion is characterized by the excretion of uric acid as the chief end-product of nitrogen metabolism), but its purification has hitherto not been simple, and the yield not high. Starting with a partially truncated cDNA for human liver arginase recently made available, we constructed an expression plasmid that had tandemly linked tac promotors placed upstream of a full-length cDNA. By selecting Escherichia coli strain KY1436 as the host micro-organism, we established an efficient system for the production of human liver arginase protein. Chromatographies on CM-Sephadex G-150, DEAE-cellulose and Sephadex G-150, followed by preparative agar-gel electrophoresis, yielded 10 mg of apparently homogeneous enzyme protein from 1 g (wet wt.) of E. coli cells. E. coli-expressed human liver arginase had chemical, immunological and most catalytic properties indistinguishable from those of purified human erythrocyte arginase. However, E. coli-expressed arginase was a monomer of Mr 35,000, whereas the purified erythrocyte arginase was trimer of Mr 105,000. They differed also in pH- and temperature-stabilities. Gel-filtration experiments with these two purified arginases under various conditions, as well as with unfractionated human liver and erythrocyte cytosol preparations, indicated that the native form of human arginase should be of Mr 35,000, and that the trimeric appearance of human erythrocyte arginase after purification was an artifact of the purification procedures. It was thus concluded that, in Nature, the liver and erythrocyte arginases are identical proteins.

Amino Acid Sequence↗
PubMed1990

A flow injection analysis system involving immobilized NADH oxidase in column form for clinical analysis.

A highly sensitive FIA system for chemiluminometric determination of reduced coenzyme, NADH, was developed, using immobilized NADH oxidase from Brevibacterium ammoniagenes. The enzyme catalyzed the oxidation of NADH generating hydrogen peroxide which emitted chemiluminescence when mixed with luminol and potassium ferricyanide. The immobilized enzyme reactor was a mini-column, measuring 1 or 2 mm in inner diameter and 20 mm in length, and the sample volume was only 1 microliter per assay, with a feeding speed of one sample per min and a lowest detection limit of 10 pmol NADH. A FIA system was also developed for the determination of magnesium in human serum, using an enzyme column reactor with simultaneously coimmobilized hexokinase, D-glucose-6-phosphate dehydrogenase, and NADH oxidase. The performance of the system was as satisfactory as a routine colorimetric assay, but with much higher sensitivity.

Colorimetry↗
PubMed1989

Purification and properties of human erythrocyte arginase.

An efficient method for purification of human erythrocyte arginase was developed. This method included two new procedures, hydrophobic chromatography and immunoaffinity chromatography, and yielded 0.7 mg of homogeneous arginase protein from 2.1 L of haemolysate. The molecular weight of native arginase was estimated to be 105,000 by gel filtration on a Sephadex G-150 column, and that of its subunit 35,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. This indicates that the native enzyme is composed of three homologous subunits. Amino acid composition of human erythrocyte arginase was found to be very similar to that of liver arginase of several other mammals. After dialysis against distilled water, the purified arginase still retained its enzymatic activity which was decreased by EDTA and reversibly restored by Mn(II) ion. A specific polyclonal antibody for use in an immunoassay was also produced. This antibody revealed one single band on immunoelectrophoretic analysis of the acetone powder extract, suggesting absence of arginase isoenzymes in human erythrocytes.

Amino Acids↗