Search PubMed⌕ Search

Biomedical subjects

K Ueda

Publications and source records attributed to K Ueda.

At least 901 records · Page 50Linked to original sources
PubMed1991

Expression of human P-glycoprotein in yeast cells--effects of membrane component sterols on the activity of P-glycoprotein.

A human MDR1 cDNA was introduced into yeast cells. Immunoblot analysis and indirect immunostaining showed that some of the P-glycoprotein produced was situated in its native orientation in the yeast plasma membrane. Drug-binding activities of the recombinant P-glycoproteins were markedly decreased compared to that of the authentic P-glycoprotein. To identify the bases of decreased binding we studied the effects of membrane component sterols on the azidopine binding and found that ergosterol, which is the main sterol in the yeast membrane, and calciferol, which is produced from ergosterol by UV irradiation, inhibited azidopine binding. These sterols in yeast membrane probably inhibit the function of human P-glycoprotein as a multidrug transporter in yeast cells, because expression of P-glycoprotein in yeast cells did not confer resistance to doxorubicin.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

[Detection of hepatitis C virus RNA in serum during treatment of chronic hepatitis C with interferon alpha].

We estimated HCV RNA in serum of 20 patients with chronic hepatitis C during interferon therapy using a combination assay of reverse transcription and polymerase chain reaction (RT-PCR). RNA was extracted from 200 microliters of serum. The primers were chosen from the NS3 region of prototype HCV RNA sequence. After 40 cycles of PCR, the products were analyzed by Southern hybridization. HCV RNA was detected in 18 of 20 (90%) patients before therapy. In cases with improvement of serum GPT level, HCV RNA became undetectable at 4 weeks of the therapy. However, HCV RNA reappeared within 4 weeks after the therapy in cases with relapse. In the no response group, HCV RNA did not disappear during the therapy. Interferon therapy is beneficial in improvement of viremia of HCV, and the detection of HCV RNA in serum is useful to evaluate the antiviral effect of interferon.

Adult↗
PubMed1991

[The examination of DNA strand breaks induced by peplomycin-using non-radioactive in situ nick translation method].

In situ nick translation (ISNT) is a method to detect DNA single strand break (nick) at each cellular level. In this study, peplomycin (PEP)-induced DNA strand breaks and its repair were examined using non-radioactive ISNT method. Human fibroblasts were cultured with various concentrations of PEP for different durations, and then DNA strand breaks were evaluated by ISNT method. The signal intensity of DNA strand breaks of the PEP-treated fibroblasts was increased in a dose dependent manner. At the fixed concentration of PEP, it reached to a maximum level after 10 min. of culture and remained unchanged for at least 24 hours. In addition, DNA strand breaks induced by PEP was rapidly repaired in 10 min. after washing. Thus, the non-radioactive ISNT is thought to be a quick, sensitive and specific method not only to detect DNA strand breaks but also to observe its repair.

Bleomycin↗
PubMed1991

[The effect of recombinant human granulocyte colony-stimulating factor (rG-CSF) on childhood neutropenias].

The clinical effect of recombinant human granulocyte colony-stimulating factor (rG-CSF), produced by Chinese hamster ovary cells, was studied in 27 patients with childhood neutropenias. The sample consisted of 8 patients with congenital neutropenia (Kostmann type), 9 with neutropenia with miscellaneous causes (5 chronic benign, 2 associated with hypogammaglobulinemia, 1 drug-induced, and 1 hypoplastic type), 3 with cyclic neutropenia, and 7 with severe aplastic anemia. The rG-CSF was given subcutaneously (or in a few cases intravenously) at a dose of 2 micrograms/kg/day for 7 days and 5 micrograms/kg/day for additional 7 to 28 days in cases with poor response. The rG-CSF was effective in 18 of 27 cases (67%). Patients with congenital neutropenia and aplastic anemia responded less frequently and poorly. The mean level of absolute neutrophil counts of 8 congenital neutropenia cases increased from 88/microliters to 2,718/microliters. That of 9 miscellaneous cases changed from 189/microliters to 7,224/microliters at a dose of 2 micrograms/kg/day. In 7 aplastic anemia cases pretreatment level of 220/microliters rose to 851/microliters, usually after increasing the dose up to 5 micrograms/kg/day. The rG-CSF was apparently effective in 3 cases of cyclic neutropenia. In any type of neutropenia, the effect was largely transient; after the discontinuation of rG-CSF, the absolute neutrophil counts tended to decrease to pretreatment levels within 1 to 2 weeks. The G-CSF was well tolerated, and only one case with mild lumbago and another with minimal elevation of transaminases were observed. We conclude that the rG-CSF can be effective for treating various types of childhood neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

HLA typing using IL-2 activated T lymphocytes: usefulness in pediatric candidates for allogeneic bone marrow transplantation.

Following a preliminary study in healthy blood donors, we have performed serological HLA-A, B, C, DR and DQ typing using recombinant IL-2 activated T lymphocytes (IL-2.aTLs) in pediatric candidates for allogeneic bone marrow transplantation. In such patients, it is often difficult to obtain the quantity of lymphocytes required for HLA typing, particularly for class II typing using B lymphocytes, considering the timing of sampling and the volume of blood to be collected. Peripheral blood mononuclear cells (PBMCs) were activated and expanded with IL-2 until a sufficient number of IL-2.aTLs of good viability were available for the typing. In the first 10 cases, analyses of surface markers (CD2, CD20, CD25, CD36, HLA-DR and HLA-DQ, CD2/HLA-DR: two color) of IL-2.aTLs were done using flow cytometry at the time of HLA typing and indicated that IL-2.aTLs expressed HLA-DR and DQ antigens sufficient for evaluation. A small number (less than 10(6] of fresh or cryopreserved PBMCs, even those containing leukemic blast cells, were sufficient to induce and expand IL-2.aTLs for HLA typing. To date we have been able to successfully HLA-A, B, C, DR and DQ type 20/20 pediatric candidates. The HLA antigens identified on the patients' IL-2.aTLs were confirmed by a family study.

Adolescent↗
PubMed1991

[Current status of the conservative treatment of urinary bladder for invasive bladder cancer].

During the 3 years from 1987 to 1990, we gave hyperthermia to 11 of the patients who visited our department for the treatment of invasive bladder cancer. Results and prognosis are reported. Stage and grade of the cancer before the treatment in 11 cases were T2 in 5 cases, T3 in 3 cases, T4 in 3 cases, transitional cell carcinoma (TCC) grade 2 in 8 cases, TCC grade 3 in 2 cases, and TCC grade 3 + anaplastic carcinoma in 1 case. Complications were observed in 8 of the 11 cases, such as severe heart disease and others. Pretreatment of radiation therapy, transurethral resection or chemotherapy was given in all cases. Hyperthermia was performed combined with hydroxypropyl cellulose-(HPC)-adriamycin, or radiation therapy, and the following results were obtained: complete response (CR) in 4 cases, partial response (PR) in 4 cases, no change (NC) in 2 cases and progressive disease (PD) in 1 case. Among 4 cases of PR, total cystectomy was performed in 3 cases. These 3 cases and the 4 cases of CR are alive now, but the other 4 patients died.

Carcinoma↗
PubMed1991

[Relaxation and diastolic filling precisely evaluated in patients with left ventricular dysfunction].

To assess left ventricular (LV) diastolic function in patients with LV dysfunction, LV pressures (manometer tip) and biplane angiograms were analyzed for 27 patients with LV systolic dysfunction (EF < or = 0.45) (dilated cardiomyopathy or coronary artery disease) and 18 normal controls. LV volumes were obtained from frame-by-frame analyses of angiograms. LV relaxation was assessed by the time constant (T) of LV pressure decay. LV relaxation was impaired in patients with LV dysfunction, however, early diastolic filling assessed by the peak filling rate (PFR) and mean filling rate (MFR) during the rapid filling phase was maintained. Compared to the control group, early diastolic filling was significantly decreased in patients with LV dysfunction without mitral regurgitation (MR), but not in those with LV dysfunction with MR. In conclusion, although diastolic filling may be modified by MR, LV relaxation and early diastolic filling are essentially impaired in patients with LV dysfunction.

Adolescent↗
PubMed1991

Serum interleukin-1 and tumor necrosis factor activities in febrile children with acute leukemia.

In order to determine whether a relationship exists between levels of serum interleukin-1 (IL-1) and tumor necrosis factor (TNF) and the incidence of fever in malignant disease and infection, IL-1 and TNF levels in 60 children with acute leukemia, 18 children with bacterial infection, and 10 children with viral infection were compared with those of 20 healthy children. IL-1 levels greater than 100 pg/ml were seen in two febrile leukemic patients and six bacteria-infected patients, and the bacteria-infected group as a whole had IL-1 levels significantly higher than those of healthy children (p less than 0.05). TNF levels greater than 50 pg/ml were noted in six febrile leukemic patients and two bacteria-infected patients (both of whom were complicated by septic shock). No single group showed significantly higher levels when compared to healthy children. All patients showing high IL-1 or TNF levels had fevers at the time of diagnosis. These findings suggest that fever in bacterial infection is associated with the production of IL-1 but not TNF (except in cases of septic shock), whereas fever in acute leukemia may be associated with the production of either IL-1 or TNF. Monitoring patients with acute leukemia for IL-1 and TNF levels throughout the clinical course of disease may help clarify the causes of febrile episodes.

Child↗
PubMed1991

Effect of breast implants on mammography.

We developed an experimental, reproducible method of evaluating the radiographic characteristics of breast implants in vitro using a mammographic phantom and a cadaver. Implant shells tested included smooth silicone, textured silicone, and silicone coated with polyurethane foam. Each type of shell was subsequently filled with saline, silicone gel, and peanut oil; the images were recorded radiographically. Textured silicone and smooth silicone shells minimally impair detection of artifacts. Polyurethane-coated shells are less radiolucent but allow visualization of some microcalcifications. Saline and silicone-gel-filled implants are radiopaque regardless of shell type. Textured silicone and smooth silicone shells filled with peanut oil are radiolucent and allow visualization of microcalcifications and most soft-tissue masses. These data demonstrate that radiolucent breast implants are possible, and further efforts are under way to achieve Food and Drug Administration approval for clinical testing.

Breast↗
PubMed1990

Translation of hepatitis B virus DNA polymerase from the internal AUG codon, not from the upstream AUG codon for the core protein.

Hepatitis B virus DNA replicates via its own polymerase that also acts as reverse transcriptase (Summers and Mason, 1982). This enzyme is encoded by a 3.5 Kb mRNA transcript covering the whole genome. Since the same transcript also codes for the core protein, and since the core open reading frame (ORF) is located upstream of the pol ORF, it has been suggested that the polymerase is first produced as a core-pol fusion protein that subsequently undergoes cleavage. This is already known to be the case with retrovirus reverse transcriptase, for which a gag-pol fusion protein is made first and the latter protein is liberated by proteolytic cleavage. We investigated this problem using mutants that were modified at the translation initiation codon for the core and precore ORF. Our findings suggested that polymerase translation occurred from the internal AUG codon independently of core protein synthesis, and that obligatory production of the core-pol fusion protein is accordingly unlikely.

Base Sequence↗
PubMed1990

Expression of a human complementary DNA for the multidrug resistance gene in murine hematopoietic precursor cells with the use of retroviral gene transfer.

In multidrug resistance, cells become simultaneously resistant to anthracyclines, vinca alkaloids, epipodophyllotoxins, and certain other natural product cytotoxic drugs. Resistance results from synthesis of a multidrug transporter (P-glycoprotein) encoded by the MDR1 gene (also known as the PGY1 gene). In the present study, a retrovirus vector containing a complementary DNA for the human multidrug resistance gene HaMDR1/A was used to transfer the multidrug resistance phenotype to bone marrow cells of the DBA/2J mouse. A high proportion of transduced bone marrow cells showed resistance to both colchicine and vinblastine, as determined by in vitro colony formation of hematopoietic precursor cells. In addition, brief culturing of the cells in a cytotoxic drug following exposure to the retrovirus vector could be used to increase the proportion of bone marrow cell colonies that were resistant. These results may serve as a model for the generation and selection of bone marrow cells resistant to the toxic effects of chemotherapeutic agents in vivo.

Animals↗
PubMed1990

Cloning of a full-length cDNA encoding bovine thymus poly(ADP-ribose) synthetase: evolutionarily conserved segments and their potential functions.

The primary structure of bovine thymus poly(ADP-ribose) synthetase, as deduced from the nucleotide sequence of a cloned cDNA, indicated that this enzyme is composed of 1016 amino acids (aa) with an Mr of 113,481. An abundance of Lys and Arg residues was in accord with the known basic nature of this protein. A comparison with reported sequences of human counterparts revealed: (1) three functional domains separated by partial proteolysis, i.e., DNA-binding (N-terminal), automodification (central), and NAD-binding (C-terminal) domains, have, in this order, increasing degrees of homology; (2) the DNA-binding domain is composed of two distinct regions: one, less conserved, containing zinc-binding fingers and the other, more conserved, containing helix-turn-helix motifs; (3) all Glu and Asp residues in the automodification domain are conserved; and (4) a 78-aa stretch encompassing the nucleotide-binding fold in the NAD-binding domain is completely conserved. These results are compatible with specific features of each domain, i.e., complex DNA-enzyme interactions, multiple automodification at acidic aa residues, and a stringent specificity for the substrate, NAD.

Amino Acid Sequence↗
PubMed1990

Abnormal responses of myeloid progenitor cells to recombinant human colony-stimulating factors in congenital neutropenia.

The effects of recombinant human interleukin-3 (IL-3) and recombinant human granulocyte colony-stimulating factor (G-CSF) on the growth of myeloid progenitor cells (CFU-C) in semisolid agar culture were studied in two patients with Kostmann-type congenital neutropenia. CFU-C growth in bone marrow cells from patients was significantly reduced in response to various concentrations of either IL-3 or G-CSF alone, compared with that from normal subjects. There was no inhibitory effect of bone marrow cells from patients on normal CFU-C formation supported by IL-3 or G-CSF. However, the simultaneous stimulation with IL-3 and G-CSF induced the increase of CFU-C formation in patients with congenital neutropenia. Furthermore, CFU-C growth in both patients was supported when bone marrow cells were preincubated with IL-3 in liquid culture followed by the stimulation with G-CSF in semisolid agar culture. In contrast, that was not supported by the preincubation with G-CSF and the subsequent stimulation with IL-3. This evidence suggests that the hematopoietic progenitor cells in patients with congenital neutropenia have the potential for developing CFU-C in the combined stimulation with IL-3 and G-CSF, and that this growth may be dependent on the priming of IL-3 followed by the stimulation with G-CSF. The level of mature neutrophils in peripheral blood was not fully restored to normal levels by the daily administration of G-CSF in doses of 100 to 200 micrograms/m2 of body surface area for 20 to 25 days in both patients. These observations raise the possibility that the combination of IL-3 and G-CSF might have a potential role for the increase of neutrophil counts in patients with congenital neutropenia.

Agranulocytosis↗
PubMed1990

Inhibition of poly(ADP-ribose) synthetase by unsaturated fatty acids, vitamins and vitamin-like substances.

Various vitamins and vitamin-like substances inhibited the activity of poly(ADP-ribose) synthetase in vitro. The most potent were essential fatty acids, i.e. arachidonic acid, linoleic acid, and linolenic acid; their 50% inhibitory concentrations (IC50) were 44-110 microM, indicating a higher potency than nicotinamide, a well-known vitamin inhibitor (IC50 = 210 microM). Vitamins K3, K1, and retinal were the next strongest inhibitors, followed by alpha-lipoic acid, coenzyme Q0, and pyridoxal 5-phosphate. Nicotinamide and vitamin K3 exhibited mixed-type inhibition with respect to NAD+, while arachidonic acid exhibited dual inhibitions, competitive at 50 microM and mixed-type at 100 microM.

Animals↗
PubMed1990

Use of recombinant P-glycoprotein fragments to produce antibodies to the multidrug transporter.

Multidrug-resistance of human cancer cells may result from expression of a 170,000 dalton multidrug efflux pump called P-glycoprotein. To identify this multidrug transporter, and to study its structure and function, we have generated polyclonal rabbit antibodies against the amino-terminal and carboxy-terminal halves of the molecule using recombinant protein fragments produced in Escherichia coli. Two recombinant P-glycoprotein fragments, representing amino acids 140-228 and 919-1280, were overproduced in Escherichia coli by an inducible T7 expression system, gel-purified and injected into rabbits. Both antisera specifically immunoprecipitate 3H-azidopine and 35S-methionine labeled P-glycoprotein from multidrug-resistant cells and detect P-glycoprotein on Western blots with high sensitivity. Because these antisera were raised against epitopes in the amino- and carboxy-terminal halves of P-glycoprotein, they should be useful as research tools to define the function of these two halves of the molecule.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Genomic organization of the human multidrug resistance (MDR1) gene and origin of P-glycoproteins.

The MDR1 gene, responsible for multidrug resistance in human cells, encodes a broad specificity efflux pump (P-glycoprotein). P-glycoprotein consists of two similar halves, each half including a hydrophobic transmembrane region and a nucleotide-binding domain. On the basis of sequence homology between the N-terminal and C-terminal halves of P-glycoprotein, we have previously suggested that this gene arose by duplication of a primordial gene. We have now determined the complete intron/exon structure of the MDR1 gene by direct sequencing of cosmid clones and enzymatic amplification of genomic DNA segments. The MDR1 gene includes 28 introns, 26 of which interrupt the protein-coding sequence. Although both halves of the protein-coding sequence are composed of approximately the same number of exons, only two intron pairs, both within the nucleotide-binding domains, are located at conserved positions in the two halves of the protein. The other introns occur at different locations in the two halves of the protein and in most cases interrupt the coding sequence at different positions relative to the open reading frame. These results suggest that the P-glycoprotein arose by fusion of genes for two related but independently evolved proteins rather than by internal duplication.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Quantitative analysis of pre-S1 and pre-S2 in relation to HBsAg expression.

Sera from four patients with acute hepatitis B and 87 patients with chronic hepatitis B were examined quantitatively for pre-S1 and pre-S2 antigens by solid-phase enzyme immunoassays. Pre-S1 and pre-S2 antigens were detected in HBsAg-positive sera irrespective of the presence of viral replicative markers, and their titers correlated with those of HBsAg (r = 0.74, p less than 0.01; r = 0.74, p less than 0.01, respectively). Sera positive for HBeAg showed higher titers of pre-S1 (p less than 0.01) and pre-S2 (p less than 0.01) antigens than sera negative for HBeAg. The titers of pre-S1 and pre-S2 antigens also correlated with the levels of HBV-associated DNA polymerase activity (r = 0.51, p less than 0.01; r = 0.59, p less than 0.01, respectively) and HBV-DNA (r = 0.50, p less than 0.01; r = 0.46, p less than 0.01, respectively). However, the ratios between the titers of pre-S antigens and HBsAg had no significant relationships with those viral replicative markers. These findings suggest that the expression of pre-S antigens is intimately related to the expression of HBsAg and that they are not useful as markers of viral replication. The ratios between the titers of pre-S antigens and HBsAg tended to be high in patients with chronic active hepatitis and high aminotransferase levels. This finding may have been due to the hepatic release of pre-S antigens, over-production of which may have some relationship to liver injury.

Acute Disease↗