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Biomedical subjects

E Shimizu

Publications and source records attributed to E Shimizu.

At least 91 records · Page 5Linked to original sources
PubMed1997

Relationship between the glutamate production and the activity of 2-oxoglutarate dehydrogenase in Brevibacterium lactofermentum.

Enzyme activities of 2-oxoglutarate dehydrogenase complex and glutamate dehydrogenase of wild type Brevibacterium lactofermentum, one of the typical glutamate-producing coryneform bacteria, were investigated by using cells cultured under glutamate-productive and glutamate-non-productive conditions. Significant reduction of the former enzyme activity was observed in the cells under the several glutamate-productive conditions, namely, in the cells cultured in media containing a) limited concentrations of biotin, b) sub-lethal amounts of penicillin, and c) sub-optimal amounts of a surface-active agent, as compared with those under the non-productive conditions. The activity of the latter enzyme was essentially unchanged in every condition. The relationship between glutamate production and the enzyme activities as well as permeability of glutamate through cell membrane was discussed from the results obtained.

Biotin↗
PubMed1997

L-Myc overexpression and detection of auto-antibodies against L-Myc in both the serum and pleural effusion from a patient with non-small cell lung cancer.

Non-small cell lung cancer patient was found to have auto-antibodies against L-Myc in both the serum and pleural effusion. The titer of anti-L-Myc antibodies was higher in the pleural effusion than in the serum. Overexpression of L-Myc without DNA amplification was observed in the tumor cells. L-Myc antigen was not detected in either the serum or the pleural effusion. Anti-nuclear antibodies were also detected in both the serum and pleural effusion, although this patient did not have collagen-vascular disease.

Aged↗
PubMed1997

Tumor suppressor genes in human lung cancer.

Lung cancer is the most common cause of cancer death in Japanese males, the incidence having increased markedly in recent years. Carcinogen exposure such as to tobacco-smoke and air pollution are associated with the probability of developing lung cancer. Aquired somatic mutations play an important role in the pathogenesis of environmentally induced lung cancers. Cytogenetic and molecular analysis of lung tumors has made it possible to examine this hypothesis and to search for candidate genes that may be targeted by chronic exposure to these carcinogens. Early studies implicate several distinct chromosomal loci (3p, 9p, 13q, 17p, and others) and suggest sequential genetic events occur during the initiation and progression of lung carcinogenesis. Several suppressor genes including Rb (13q), P53 (17p), and P16 (9p) have been identified and cloned at these chromosomal loci. The identification of putative tumor suppressor gene at chromosome 3p is still under work. Understanding the interaction of P53, RB, cyclins, and protein kinase inhibitors including P16 will be essential to the development of the next generation of diagnostic and therapeutic studies for lung cancer.

Chromosomes, Human↗
PubMed1996

Expression, regulation and polymorphism of the mxi1 genes.

The myc proto-oncogene family plays an important role in the control of cellular growth and differentiation. Mxi1, one of the Max-associated proteins, has been known to have an antagonistic action on Myc activity. The mxi1 mRNA increased during growth inhibition and differentiation, and decreased with serum stimulation in mammal cell lines. We have also found an AAAAC polymorphic repeat in the 3' non-coding region of the human mxi1 cDNAs and a difference between the mxi1 mRNA half-lives in some different cell lines.

Base Sequence↗
PubMed1996

Detection of auto-antibodies against L-myc oncogene products in sera from lung cancer patients.

Auto-antibodies against L-myc oncogene products (L-Myc) in sera from lung cancer patients were examined using bacterially synthesized glutathione S-transferase (GST) L-Myc fusion proteins and Western blot analysis. The detection rate of anti-L-Myc antibodies in sera from lung cancer patients was 10%, while that in sera obtained from normal volunteers was 0%. Five patients with non-small-cell lung cancers (2 adenocarcinomas, 2 squamous-cell carcinomas and I large-cell carcinoma) were included in the group with anti-L-Myc antibodies. These auto-antibodies belonged to the IgG class and recognized the carboxy terminus of L-Myc. Circulating L-Myc was not detected in sera from patients with anti-L-Myc antibodies. Differences in age, sex, performance status, histology, stage, smoking history and prior treatment were not significantly different between anti-L-Myc antibody-positive and antibody-negative patients. Anti-nuclear antibodies were detected in 40% of lung cancer patients and 57% of those with anti-L-Myc antibodies. Our data suggest that detection of anti-L-Myc antibodies may be helpful in the diagnosis and evaluation of the host-immune response to L-Myc in a subset of lung cancer patients.

Aged↗
PubMed1996

Establishment and characterization of two cultured cell lines derived from malignant rhabdoid tumors of the kidney.

Malignant rhabdoid tumor of the kidney (RTK) is a rare renal sarcoma of childhood. Its histogenesis is unclear, and it is highly resistant to multimodality therapy. To elucidate the origin and the oncogenetic potential of RTK, we investigated the characteristics of 2 newly established RTK cell lines, SWT-1 and SWT-2. Both cell lines were verified to be RTK, since they did not exhibit contact inhibition and exhibited intermediate filaments, a specific marker for RTK. These cells possess the characteristics of mesenchymal cells based on their positive reactions with anti-vimentin and anti-laminin antibodies and their negative reactions with anti-keratin and anti-desmin antibodies. The karyotype of SWT-1 was 46,XX and that of SWT-2 was 46,XX,del(11)(pter-p13::p12-qter). Since 11p13 is the location of the WT-1 tumor-suppressor gene, and del(11p13) is associated with the aniridia-Wilms'-tumor syndrome, these findings link RTK with Wilms' tumor. While SWT-1 was negative for the tumor markers examined, SWT-2 released tissue polypeptide antigen into the culture supernatant. No rearrangement or amplification of the myc and ras oncogenes or of the p53 tumor-suppressor gene were detected. Wild-type RB protein and cyclin A were expressed in both cells. Our data suggest that these 2 cell lines may be useful in identifying the oncogenetic pattern of RTK.

Antineoplastic Agents↗
PubMed1996

Stem-cell factor regulates the expression of cyclin A and retinoblastoma gene product in the growth and differentiation pathway of human megakaryocytic cells.

The biological effects of c-kit ligand (stem-cell factor: SCF) on an immortalized human megakaryocytic cell line (CMK) was evaluated using methods including the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, surface marker analysis, DNA cell-cycle analysis and immunoblotting. SCF stimulated the growth of CMK cells. Incubation with SCF resulted in increased expression of IIb/IIIa platelet-related glycoprotein (gpIIb, IIIa), indicating enhanced differentiation of CMK cells. Treatment of CMK cells with SCF resulted in a decrease in the subpopulation in the G1 phase, with a reciprocal increase in those in the S phase and the G2 + M phase. Moreover, SCF significantly increased cellular expression of cyclin A, a regulatory subunit of cyclin-dependent protein kinase (CDK), and the ratio of phosphorylated/dephosphorylated retinoblastoma gene product (RB protein). These results suggest that SCF stimulates the growth and differentiation of megakaryocytic cells possibly through mechanisms related to the activation of cell-cycle-dependent serine/threonine kinase and inactivation of the nuclear tumor-suppressor gene product.

Cell Differentiation↗
PubMed1995

Copper/topa quinone-containing histamine oxidase from Arthrobacter globiformis. Molecular cloning and sequencing, overproduction of precursor enzyme, and generation of topa quinone cofactor.

The gene coding for histamine oxidase has been cloned and sequenced from a Coryneform bacterium Arthrobacter globiformis. The deduced amino acid sequence consists of 684 residues with a calculated molecular mass of 75,109 daltons and shows a high overall identity (58%) with that of phenethylamine oxidase derived from the same bacterial strain. Although the sequence similarities are rather low when compared with copper amine oxidases from other organisms, the consensus Asn-Tyr-Asp/Glu sequence, in which the middle Tyr is the precursor to the quinone cofactor (the quinone of 2,4,5-trihydroxyphenylalanine, topa) covalently bound to this class of enzymes, is also conserved in the histamine oxidase sequence. To identify the quinone cofactor, an overexpression plasmid has been constructed for the recombinant histamine oxidase. The inactive enzyme purified from the transformed Escherichia coli cells grown in a copper-depleted medium gained maximal activity upon stoichiometric binding of cupric ions. Concomitantly with the enzyme activation by copper, a brownish pink compound was generated in the enzyme, which was identified as the quinone of topa by absorption and resonance Raman spectroscopies of the p-nitrophenylhydrazine-derivatized enzyme and found at the position corresponding to the precursor Tyr (Tyr-402). Therefore, the copper-dependent autoxidation of a specific tyrosyl residue operates on the formation of the topa quinone cofactor in this enzyme, as recently demonstrated with the precursor form of phenethylamine oxidase (Matsuzaki, R., Fukui, T., Sato, H., Ozaki, Y., and Tanizawa, K. (1994) FEBS Lett. 351, 360-364).

Amine Oxidase (Copper-Containing)↗
PubMed1995

Cloning and sequencing of the murine Mxi1 cDNA.

The cloning and sequencing of the murine Mxi1 gene encoding Mxi1, one of Max-associated proteins, is described. Murine and human sequences showed 87.9% nucleotide (nt) and 90.3% amino acid (aa) sequence homology, whereas murine and zebra fish sequences showed 67.2% nt and 67.8% aa sequence homology.

Amino Acid Sequence↗
PubMed1995

Culture conditions for improvement of L-threonine production using a genetically self-cloned L-threonine hyperproducing strain of Escherichia coli K-12.

We had constructed an L-threonine-hyperproducing strain of E. coli K-12 by recombinant DNA techniques. In this paper, culture conditions for the practical production of L-threonine were investigated using this strain. Cultivation temperature, concentration of required amino acids, and dissolved oxygen greatly influenced the yield of L-threonine. High production of L-threonine was obtained at a high level of dissolved oxygen for the recombinant strain, but not for the parent. This improved production was accompanied by a high copy number of recombinant plasmids and high activity of aspartokinase. Initial addition of L-threonine together with required amino acids greatly reduced the net production of L-threonine. To remove the reductive effect, methods for the addition of the required amino acids were tested. Lowering the required amino acids at a later stage of cultivation seemed to be effective to avoid the reductive effect of the accumulated L-threonine. By using the optimal conditions, the highest level of L-threonine production, 65 g/l, 48% yield, was achieved.

Amino Acids↗
PubMed1995

Degradation of 2-ketoarginine by guanidinobutyrase in arginine aminotransferase pathway of Brevibacterium helvolum.

Guanidinobutyrase (EC 3.5.3.7) involved in the arginine oxygenase pathway of Brevibacterium helvolum IFO 12073 was found to catalyze also the hydrolysis of 2-ketoarginine (2-keto-5-guanidinovalerate) to 2-ketoornithine (2-keto-5-aminovalerate) and urea, the second step of the arginine aminotransferase pathway. No other enzyme that degraded 2-ketoarginine was found in cells grown on L-arginine. The enzyme hydrolyzed 2-ketoarginine with a relative rate of about 0.7% of that toward 4-guanidinobutyrate. The Km for 2-ketoarginine was 33 mM.

Arginine↗
PubMed1995

[Identification and analysis of immune cells infiltrating into the glomerulus and interstitium in lupus nephritis].

This study was performed to investigate the role of cell-mediated immunity in lupus nephritis (LN). Frozen sections from 38 patients with LN were examined by indirect immunoalkaline-phosphatase labeling using monoclonal antibodies to identify the immune cells infiltrating into the interstitium and glomerulus. 14 patients showed minor glomerular abnormality (MGA), 9 had mesangial LN (MesLN), 12 had diffuse proliferative LN (DPLN) and 3 had membranous LN (MLN). Monocyte/macrophage and helper/inducer T cells infiltrated in the interstitium predominantly, but intraglomerular infiltration of these cells was rare. Monocyte/macrophage and suppressor/cytotoxic T cell levels were significantly higher (p < 0.05) in the interstitium in DPLN patients and monocyte/macrophage level was significantly higher (p < 0.05) in MesLN patients than in MGA patients. In the interstitium, serum creatinine level was highly correlated with infiltrations of suppressor/cytotoxic T cell, monocyte/macrophage (p < 0.01), pan T cell and total leucocyte (p < 0.05). Clinical activity score was correlated with suppressor/cytotoxic T cell (p < 0.001), monocyte/macrophage and pan T cell (p < 0.01). These results suggest that suppressor/cytotoxic T cell and and monocyte/macrophage may play an important role in the progression of lupus nephritis.

Antibodies, Monoclonal↗
PubMed1995

Patient with extensive small cell lung cancer given moderately dose-intensified chemotherapy and peripheral blood stem cell support.

Although recent progress in multi-drug chemotherapy has increased the median survival of patients with extensive Small cell lung cancer (SCLC) to 7 months, 2-year survivors are still exceptional. We describe a 40-year-old man with extensive SCLC involving the lungs and systemic nodes who was initially treated with 6 cycles of an alternating combination regimen consisting of cyclophosphamide, doxorubicin, vincristine, cisplatin and etoposide. After the second cycle of the regimen, Peripheral blood stem cells (PBSC) were harvested and frozen. The patient then received a moderately dose-intensified regimen consisting of cisplatin (80 mg/m2) and etoposide (500 mg/m2 X 3), followed by infusion of the thawed PBSC. Hematopoietic recovery was rapid, and the patient remained tumor free for 12 months until multiple tumor recurrence.

Adult↗
PubMed1995

A case report of mixed P- and C-ANCA positive patients with pauci-immune crescentic glomerulonephritis.

We describe 2 patients with pauci-immune crescentic glomerulonephritis and elevated titers of perinuclear and cytoplasmic anti-neutrophil cytoplasmic antibody (P-ANCA and C-ANCA) which were associated with both 29 and 59 kD bands on Western blots. The presence of C-ANCA corresponds with a clinical and/or histological diagnosis of Wegener's granulomatosis, but although both patients suffered from pulmonary complications there was no clinical nor histological evidence of granulomatosis. Transbronchial lung biopsy showed only interstitial pneumonia and old hemorrhage. Therefore, the patients' conditions were interpreted as microscopic polyarteritis nodosa or hitherto undefined vasculitis associated with ANCA.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1995

FK506 and cyclosporin A inhibit granulocyte/macrophage colony-stimulating factor production by mononuclear cells in asthma.

Bronchial asthma is associated with eosinophilic inflammation and expression of T-cell-derived cytokines, which influence eosinophilic function. FK506, a newly established immunosuppressive agent, may have potential as a therapeutic instrument for asthma because of its suppressive effect on T-cell activation. To assess this, we compared the inhibitory effects of FK506 and cyclosporin A on production of granulocyte/macrophage colony-stimulating factor and interleukin-5 by interleukin-2- or Dermatophagoides farinae-stimulated mononuclear cells from patients with asthma, and their contribution to proliferation and survival of eosinophils in vitro. FK506 inhibited granulocyte/macrophage colony-stimulating factor production by stimulated mononuclear cells from asthma patients at lower concentrations than cyclosporin A. Both drugs inhibited eosinophil proliferation and survival activity from mononuclear cells at comparable concentrations. Interleukin-5 production by stimulated mononuclear cells was also inhibited both by FK506 and cyclosporin A. We conclude that both FK506 and cyclosporin A have potential for therapy of bronchial asthma.

Asthma↗
PubMed1994

Cloning and sequencing of phenylethylamine oxidase from Arthrobacter globiformis and implication of Tyr-382 as the precursor to its covalently bound quinone cofactor.

The gene of Arthrobacter globiformis encoding a quinoprotein, phenylethylamine oxidase, has been cloned and sequenced. In the deduced amino acid sequence comprising 638 residues is a tetrapeptide sequence, Asn-Tyr-Asp-Tyr, which has been found to be highly conserved in other copper amine oxidase. Mutation of the former Tyr (Tyr-382) of the recombinant enzyme into Phe resulted in the complete loss of catalytic activity and disappearance of the quinone compound that is specifically detected in the wild-type enzyme, suggesting that Tyr-382 is the precursor to the covalently-bound cofactor, most probably topa quinone. Furthermore, the expression of the active, quinone-containing enzyme in Escherichia coli cells was markedly dependent on the presence of Cu2+ ions in the culture medium, and the inactive, Cu2(+)-deficient enzyme produced without Cu2+ ions could be converted to the active quinone form by reconstitution with Cu2+ ions.

Amine Oxidase (Copper-Containing)↗