Search PubMed⌕ Search

Biomedical subjects

M Nobuhara

Publications and source records attributed to M Nobuhara.

At least 37 records · Page 2Linked to original sources
PubMed1985

Coronary thrombolysis in dogs with intravenously administered human pro-urokinase.

Coronary thrombolysis was induced by infusion of highly purified human pro-urokinase isolated from a transformed kidney cell line (ACHN) or by infusion of urokinase of urinary origin in anesthetized dogs with 1-hr-old clots in the left anterior descending coronary artery. The clots were induced with a copper coil and thrombolysis was detected by repeat coronary angiography. Intravenous infusion of pro-urokinase at a rate of 10 micrograms/kg/min for 30 min in two dogs did not induce thrombolysis, which was only obtained after 8 and 15 min of its subsequent intracoronary administration. Intravenous infusion of pro-urokinase at a rate of 20 micrograms/kg/min for 30 min in four dogs induced coronary thrombolysis within 23 +/- 2 min (mean +/- SEM). This was not associated with systemic fibrinolytic activation because the alpha 2-antiplasmin and fibrinogen levels did not decrease. Intravenous infusion of urokinase at a rate of 10 micrograms/kg/min for 30 min elicited thrombolysis in four of seven dogs within an average of 19 +/- 2 min. In the other three dogs thrombolysis was only obtained within 11 +/- 3 min of its subsequent intracoronary infusion. Administration of urokinase was associated with systemic fibrinolytic activation as evidenced by a decrease of alpha 2-antiplasmin to about 10% and of fibrinogen to 43 +/- 13% of the preinfusion value. It is concluded that intravenous infusion of pro-urokinase at a sufficiently high rate produces coronary thrombolysis without systemic fibrinolysis in dogs.

Animals↗
PubMed1984

In vitro and in vivo studies on potentiation of cytotoxic effects of anticancer drugs or cobalt 60 gamma ray by interferon on human neoplastic cells.

A possibility that interferon may potentiate the cytotoxic effects of anticancer drugs or 60Co gamma ray on human neoplastic cells was studied by in vitro and in vivo experimental procedures. The human neoplastic cells used were HeLa (uterine cervical cancer) and WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by 60Co gamma ray) cells. As normal human cells, WI-38 cells were used. Interferon was a preparation of beta-type produced by human fibroblasts. The cytotoxicity was determined by colony formation for in vitro experiments and by tumor growth for animal experiments. Of 17 anticancer drugs, the cytotoxic effects of six drugs, namely, peplomycin, bleomycin, aclacinomycin, cisplatin, 5-fluorouracil (5-FU), and Adriamycin (doxorubicin) were potentiated by concomitant application of interferon. The cytolethal effects of 60Co gamma ray were also enhanced by interferon. The growth of tumor induced by transplantation of HeLa cells into a nude mouse was remarkably reduced by combination therapy of interferon and 5-FU. The current results indicate a possibility that combined therapy of certain types of anticancer drugs or 60Co gamma ray with interferon may be effective in treatment of cancer patients.

Animals↗
PubMed1984

Potentiation of cytotoxic effects of 5-fluorouracil by inosiplex on cancer cells.

The antitumor effect of 5-fluorouracil (5-FU) was significantly enhanced by inosiplex which has been developed as a drug possessing antiviral activity. The enhancement of antitumor effect of 5-FU was demonstrated by experiments both in vitro and in vivo, viz. depression of the colony formation rate in cultures of HeLa cells (an established cell line of human cervical carcinoma), and prolongation of the survival of mice bearing transplanted Ehrlich ascites tumor of murine mammary carcinoma origin. The HeLa cell colony formation was synergistically decreased in the presence of 0.5-2.0 micrograms/ml of 5-FU combined with 100 micrograms/ml of inosiplex. Inosiplex did not cause any appreciable inhibition of cell growth at this concentration when added alone to the culture. The mean duration of survival of tumor-bearing mice was 18.2, 20.3, 31.9 and 47.1 days in the control group and groups receiving inosiplex, 5-FU, or a combination of 5-FU and inosiplex, respectively; hence significantly prolonged in the combined therapy regimen group as compared with the control and the 5-FU treated group (P less than 0.01).

Animals↗
PubMed1984

[Potentiation of cytotoxic effects of 5-fluorouracil by inosiplex on cancer cells].

Inosiplex, a 3:1 molarcomplex of N, N-dimethylamino-2-propanol-p-acetamidobenzoate and inosine, which has been reported to exhibit antiviral activity in vitro and in vivo, enhanced cytotoxic effects of 5-fluorouracil (5-FU). Effects of inosiplex on the potentiation of cytotoxicity of 5-FU were investigated in vitro and in vivo. In vitro studies demonstrated that cytotoxic effects of 5-FU on cloning efficiency of HeLa cells were prominently enhanced by inosiplex, while inosiplex alone showed no cytotoxicity at the concentrations examined. Further, the survival time of mice intraperitoneally inoculated with Ehrlich ascites tumor cells was investigated. The mean survival time of mice treated with the combination of 5-FU and inosiplex significantly prolonged as compared with that of control animals or mice treated with inosiplex alone or 5-FU alone. Since inosiplex has been clinically studied as an antiviral agent and proved to be harmless to humans, the present results indicate that a combined administration of 5-FU and inosiplex may be effective in the treatment of human cancers.

Animals↗
PubMed1983

In vitro studies on potentiation of cytotoxic effects of anticancer drugs by interferon on a human neoplastic cell line (HeLa).

Experiments were performed to ascertain whether the antitumor effect of various anticancer drugs might be enhanced by interferon, using cultures of HeLa cells originating from a human carcinoma of the uterine cervix. The effects of drugs were assessed by counting cell colonies formed in culture. The drugs studied included 4 metabolic antagonists: cytosine arabinoside (Ara-C), 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP) and methotrexate (MTX), 7 antibiotics: aclacinomycin (ACM), adriamycin (ADM), actinomycin D (ACD), cycloheximide, mitomycin C (MMC), peplomycin (PEP) and puromycin; 2 alkylating agents: nimustine hydrochloride (ACNU) and melphalan, and 3 other drugs, vincristine (VCR), cisplatin (CDDP) and hydroxyurea (HU). Interferon was a preparation of the beta-type produced by human fibroblasts. A specific additive or synergistic potentiation of the cytotoxic effect by concomitant application of interferon was observed with PEP, ACNU, ACM, CDDP, 5-FU and ADM; the drug concentration given a 50% inhibition of cell growth was reduced by one-half or more in cultures with the combination of interferon and these drugs. The treatment of cells with interferon alone caused only 10-30% inhibition of cell proliferation.

Alkylating Agents↗
PubMed1983

Interferon potentiates cytotoxic effects of 5-fluorouracil on cell proliferation of established human cell lines originating from neoplastic tissues.

A potentiation of the cytotoxic effects of 5-fluorouracil (5-FU) on human tumor cells by interferon was examined. The human neoplastic cell lines used were HeLa (uterine cervical cancer), MCF-7 (mammary cancer), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by Co-60 gamma-ray irradiation), KMM-1 (myeloma) and Raji (Burkitt's lymphoma). The normal human cell strain used was WI-38 (normal human lung fibroblasts). The cytotoxic effects were determined by colony formation for HeLa, MCF-7, WI-38 CT-1 and WI-38 cells, and by cell growth for KMM-1 and Raji cells. Each cell line was different in sensitivity to interferon or 5-FU. Interferon potentiated synergistically the cytotoxic effects of 5-FU on HeLa, WI-38 CT-1 and KMM-1 cells. In the case of Raji cells, the cytotoxic effects of the combination of interferon and 5-FU were additive. Neither synergistic nor additive lethal effects of the combination of the 2 agents were observed in MCF-7 and WI-38 cells. The present results indicate a possibility that interferon and 5-FU can mutally reduce the amount of the other needed to treat cancer patients.

Cell Line↗
PubMed1983

[Potentiation of the cytotoxic effects of various anticancer drugs by interferon on human neoplastic cells (HeLa) in culture].

Potentiation of the cytotoxic effects of various anticancer agents by interferon on human malignant cells was examined in culture. The human neoplastic cells used were HeLa cells derived from uterine cervical cancer. The interferon was produced in human diploid fibroblasts treated with Poly I:C. Anticancer drugs examined were as follows; antibiotics (aclacinomycin, actinomycin D, adriamycin, cycloheximide, mitomycin C, peplomycin, puromycin), antimetabolites (cytosine arabinoside, 5-fluorouracil, 6-mercaptopurine, methotrexate), alkylating agents (ACNU, melphalan), and others (cisplatin, hydroxyurea, vincristine). The cytotoxic effects were determined by colony formation. Our results demonstrated that interferon potentiated significantly the cytotoxic effects of peplomycin, aclacinomycin, cisplatin, 5-fluorouracil, and adriamycin on HeLa cells. The present results indicate that a combined administration of interferon and these drugs may be effective in the treatment of human cancers.

Aclarubicin↗
PubMed1983

Chemical synthesis of a human fibroblast interferon gene and its expression in Escherichia coli.

Using the solid phase phosphotriester method, a gene coding for human fibroblast interferon consisting of 166 amino acid residues was chemically synthesized. The gene obtained by ligation of 61 synthesized oligodeoxyribonucleotide fragments was inserted into the downstream of tryptophan promoter, and expressed in E. coli. Lysate of this E. coli showed the antiviral activity which was specifically neutralized by anti-fibroblast interferon antibody. No particular advantage was observed in the expression efficiency by the synthetic gene over that by the native gene.

Amino Acid Sequence↗
PubMed1982

Combined effects of 5-fluorouracil and interferon on proliferation of human neoplastic cells in culture.

The growth inhibitory effects of the combination of 5-fluorouracil (5-FU) and human fibroblast interferon on human neoplastic cell lines and normal human fibroblasts were examined. The neoplastic cell lines used were HeLa (cervical carcinoma), MCF-7 (mammary carcinoma), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by 60Co gamma-ray irradiation), KMM-1 (myeloma), and Raji (Burkitt's lymphoma). The normal human cell line used was WI-38. The growth inhibitory effects were determined by measuring colony formation for HeLa, MCF-7, WI-38 CT-1, and WI-38 cells, and by measuring cell growth for KMM-1 and Raji cells. Each cell line showed different sensitivities to 5-FU or interferon. The combination of 5-FU and interferon showed synergistic inhibitory effects on the growth of HeLa, WI-38 CT-1, KMM-1, and Raji cells. Neither synergistic nor additive growth inhibitory effects of the combination of 5-FU and interferon were observed in MCF-7 and WI-38 cells.

Animals↗
PubMed1982

[Combined effects of 5-fluorouracil and interferon on proliferation of human neoplastic cells in culture].

Potentiation of the cytotoxic effects of 5-fluorouracil (5-FU) by interferon on human tumor cells was examined. The human neoplastic cell lines used were HeLa (uterine cervical cancer), MCF-7 (mammary cancer), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by Co-60 gamma-ray irradiation), KMM-1 (myeloma), and Raji (Burkitt's lymphoma). As a normal human cell strain, WI-38 (embryonic lung fibroblasts) was used. The cytotoxic effects were determined by colony formation. Each cell line was different in sensitivity to interferon or 5-FU. Interferon potentiated synergistically the cytotoxic effects of 5-FU on HeLa, WI-38 CT-1, and KMM-1 cells. In the case of Raji cells, the cytotoxic effects of the combination of interferon and 5-FU were additive. Neither synergistic nor additive lethal effects of the combination of the two agents were observed in MCF-7 and WI-38 cells. The present results indicate a possibility that a combined treatment with interferon and 5-FU may be effective in certain types of human cancers.

Cell Division↗
PubMed1981

A comparative study of high molecular weight urokinase and low molecular weight urokinase.

Two forms of urokinase [EC 3.4.99.26] with molecular weights of 51,600 and 34,500 were purified from human urine. The specific activities of the high molecular weight urokinase (HMW-UK) and low molecular weight urokinase (LMW-UK) were 157,400 and 246,700 International Units (IU/mg), respectively. Purified HMW-UK was 97% active and LMW-UK was 88% active, as judged by using p-nitrophenyl-p'-guanidinobenzoate. LMW-UK had five multiple isoelectric subforms, compared with HMW-UK which had only one. Not only HMW-UK but also LMW-UK was composed of two polypeptide chains linked by disulfide bond(s). The molecular weight of the heavy chain of both forms was the same (34,000 daltons), while the molecular weight of the light chain of HMW-UK was 17,600 and that of LMW-UK was approximately 1,200-3,400. Enzyme kinetic studies revealed that the kinetic constants, Km and Kcat, of both forms toward the synthetic substrates, acetyl-Gly-Lys-methylester (AGLMe) and glutaryl-Gly-Arg-4-methylcoumarin-7-amide (GGA-MCA), were almost the same, but the dissociation constant of HMW-UK toward Glu-plasminogen was 2.4-2.6 times less than that of LMW-UK. HMW-UK incubated at 37 degrees C was converted into LMW-UK in an autocatalytic digestion manner leading to no loss of the total activity. These results show that HMW-UK with a higher affinity toward Glu-plasminogen is converted into LMW-UK with a lower affinity, a greater portion of the light chain of HMW-UK splitting off.

Amino Acids↗
PubMed1980

Structure of slow-reacting substance of anaphylaxis (SRS-A).

To elucidate the chemical structure of slow-reacting substance of anaphylaxis from rat (SRS-A rat), SRS-A rat were purified by the method of Orange with modification using DEAE-Sephadex A-25 chromatography. Ultraviolet absorption spectrum of purified SRS-A rat indicated the presence of conjugated triene. Arylsulfatase B degradation products and HCl degradation products were subjected to analysis by a gas chromatography and mass spectrometry and a thin layer chromatography. Products obtained by arylsulfatase b catalysis contained 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid. HCl degradation products showed the presence of glycine, glutamic acid and cysteic acid. Furthermore, the analysis of anhydrous hydrazine degradation products of SRS-A rat and of HCl hydrolyzed products of dinitrophenylated SRS-A rat revealed the presence of glycine at C-terminal and glutamine acid at N-terminal. The study of the substrate specificity of arylsulfatase B against various materials including SRS-A rat suggested the presence of sulfone in SRS-A rat. The molecular ion peak of SRS-A rat sodium salt was observed at m/e 680 in field desorption mass spectrum of SRS-A rat. On the basis of these data, we identified the structure of SRS-A rat as [gamma]glutamyl-4(5-hydroxy-7,9,11,14-eicosatetraenoic acid-6-yl)-4,4-dioxyocysteinyl] glycine.

Animals↗