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H Satake

Publications and source records attributed to H Satake.

At least 73 records · Page 4Linked to original sources
PubMed1986

Carbocyclic inosine as a potent anti-leishmanial agent: the metabolism and selective cytotoxic effects of carbocyclic inosine in promastigotes of Leishmania tropica and Leishmania donovani.

Carbocyclic inosine is a potent inhibitor for the growth of the promastigote form of Leishmania tropica and Leishmania donovani. In culture, the EC50 values of carbocyclic inosine are 8.3 X 10(-8) and 1.3 X 10(-7) M for the promastigotes of L. tropica and L. donovani, respectively. On the other hand, it is less toxic towards mouse mammary tumor FM3A cells: the EC50 value is 2.7 X 10(-4) M. Carbocyclic inosine is metabolized by Leishmania promastigotes to give carbocyclic adenosine-5'-triphosphate (aristeromycin-5'-triphosphate) and carbocyclic guanosine-5'-triphosphate. This metabolic conversion provides a mechanism for the parasite-selective toxicity of carbocyclic inosine.

Adenosine↗
PubMed1986

Synthesis of a mutagenic nucleoside, 2'-deoxy-2-(p-nitrophenyl)-adenosine.

The reaction of 2-amino-6-chloropurine riboside with i-amyl nitrite in benzene in the presence of Cu2O, followed by treatment with NH3/MeOH gave 2-phenyladenosine (1). The crude sample of 1 was found to be mutagenic to bacteria (Salmonella typhimurium TA 98 and TA 100, without metabolic activation). When this material was subjected to high pressure liquid chromatography, the mutagenic activity was found only in contaminating minor components, whose structures were assigned as 2-(m- and p-nitrophenyl)-adenosines (2m,p). In order to study structure-activity relationships, several nucleoside and base analogues were synthesized. Among them, 2'-deoxy-2-(p-nitrophenyl)-adenosine (8) was the most potent mutagen as tested either with TA 98 or TA 100.

Adenosine↗
PubMed1986

Anti-parasite activity of nucleoside analogues: the metabolism of carbocyclic inosine in promastigotes of Leishmania tropica and Leishmania donovani and its activity against amastigotes of Leishmania donovani in vitro.

Carbocyclic inosine is a potent inhibitor for the growth of the promastigote form of Leishmania tropica and Leishmania donovani. In culture, the EC50 values of carbocyclic inosine are 8.3 X 10(-8) and 1.3 X 10(-7) M for the promastigotes of L. tropica and L. donovani, respectively. On the other hand, it is less toxic towards mouse mammary tumor FM3A cells: the EC50 value is 2.7 X 10(-4)M. Carbocyclic inosine is metabolized by Leishmania promastigotes to give carbocyclic adenosine-5'-triphosphate(aristeromycin-5'-triphosphate) and carbocyclic guanosine-5'-triphosphate. This metabolic conversion provides a mechanism for the parasite-selective toxicity of carbocyclic inosine. Carbocyclic inosine was found to be active against L. donovani amastigotes in an in vivo-like cultivation in vitro.

Animals↗
PubMed1984

[CDDP-containing combination chemotherapy for advanced lung cancer].

The effect and toxicities of Cis-containing combination chemotherapy were tested in 28 patients with primary lung cancer. All patients were treated with 80 mg/m2 Cisplatinum on the first day and 750 mg ftorafur p.o. every day. In addition to these drugs, patients with squamous cell cancer were treated with continuous subcutaneous infusion of 4 mg/m2 Peplomycin for 5 days and one shot i.v. of 4 mg MMC. Patients with adeno- and large cell cancer were treated with 30 mg/m2 Adriamycin and 4 mg MMC, while patients with small cell cancer were given 150 mg/m2 VP-16 p.o. for 5 days. The following results were obtained. Of 22 evaluable patients, overall response rate was 50%. In each histologic type, response rate was 50% (5/10) for squamous cell carcinoma 50% (4/8) for adenocarcinoma 33% (1/3) for large cell carcinoma and 100% (1/1) for small cell carcinoma. No CR was obtained in this series. Main side effects due to Cisplatinum were nausea, vomiting, loss of appetite, mild leukopenia and thrombocytopenia, mild elevation of serum creatinine and BUN and alopecia, all of which were transient. Interstitial pneumonitis was observed in 40% of patients with squamous cell cancer. Two patients with adenocarcinoma died within 3 weeks after treatment due to embolism of the abdominal aorta and myocardial infarction probably caused by treatment with Adriamycin.

Adenocarcinoma↗
PubMed1983

[Daily fluctuation of background count rate of a liquid scintillation counter].

3H channel count rate of 3 background samples were measured for 8 days. Sample A and C were different scintillators in 100 ml teflon vials and sample B in a 20 ml glass vial. Count rate of sample A fluctuated from 3 to 7 cpm, and that of C from 6 to 12 cpm, respectively. However, count rate of sample B was about 6 cpm and rather constant. Trend of fluctuation in count rate of sample A and C were observed to be similar. On weekdays, count rate increased at night and decreased in day time. At weekend, count rate increased from Saturday evening and was constant from Sunday noon till Monday morning. Tritium Research Center where LSC is placed is ventilated from 9 a.m. to 6 p.m. on weekdays, and the ventilation is suspended on Sunday. The observed fluctuation of background was apparently related to the operation and suspension of ventilation. When ventilation was operated continuously, count rates of sample A (4 cpm) and sample C (6 cpm) became constant and corresponded to their minimum value. The fluctuation of background may be caused by radon, concentration of which varies in association with the operation and suspension of ventilation.

Background Radiation↗
PubMed1981

Structure and synthesis of a lipid-containing bacteriophage. Amphiphilic properties of protein IV of bacteriophage PM2.

Interactions between lipids and the DNA-binding protein (protein IV) purified from bacteriophage PM2 were studied in vitro. The efficiency of incorporation of protein IV into single-walled liposomes was more than 90%. Protein IV embedded in liposomes interacted more strongly with PM2 DNA than protein IV alone. The DNA--protein-IV--liposome complex was relatively stable as observed by sedimentation behavior on a sucrose gradient. The interaction between DNA and the protein-IV--liposome was abolished by tryptic digestion, even though 40% of the protein remained in the vesicle. More than 70% of the amino acids of this embedded peptide segment were hydrophobic. Carboxypeptidase digestion of the protein-IV--liposome caused a release of 20% of the radioactivity of the vesicle without changing the DNA-binding ability of the complexes. Modification of the protein-IV--liposome with the chemical probe, 2,4-dinitrofluorobenzene, and analysis of the tryptic peptides released from the protein-IV--liposome demonstrated that the N-terminal basic amino acid cluster segment responsible for the DNA binding was located on the outer surface of the bilayer. These results support an earlier model in which protein IV anchors itself in the inner leaflet of the PM2 bilayer membrane, interacting with the DNA in the virion.

Bacteriophages↗
PubMed1980

Multiple forms of cytochrome P-450 purified from liver microsomes of phenobarbital- and 3-methylcholanthrene-pretreated rabbits. I. Resolution, purificaton, and molecular properties.

A method is described for the separation and purification of different forms of cytochrome P-450 from liver microsomes of phenobarbital (PB)- and 3-methylcholanthrene (MC)-pretreated rabbits. It consists of solubilization of microsomes with cholate, followed by successive chromatography on omega-aminooctyl Sepharose 4B, hydroxylapatite and CM-Sephadex C-50 columns. Separation of different forms of cytochrome P-450 is achieved in the aminooctyl Sepharose and hydroxylapatite chromatograhy steps. This method permits the separation of three forms of cytochrome P-450, i.e. "P-450(1)," "P-450(2)," and "P-488(1)," from PB-induced microsomes; P-450(1), the main cytochrome P-450 component in these microsomes, and P-448(1) can each be obtained in a gel-electrophoretically homogeneous state, whereas P-450(2) can be obtained in a partially purified state. Application of the same method to MC-induced microsomes led to the purification of P-448(1), the main component in these microsomes, to homogeneity and to partial purification of a fourth form, i.e. "P-450(3)." P-448(1) from MC-induced microsomes seems to be identical with P-448(1) from PB-induced microsomes in monomeric molecular weight (54,000), amino acid composition and chromatographic behavior. However, P-448(1) from MC-induced microsomes, but not P-448(1) from PB-induced microsomes, contains 0.18 to 0.88 mol of tightly bound MC per mol of protein. P-450(1) has a molecular weight of 49,000 and its amino acid composition is clearly different from that of P-448(1). Although P-450(2) is similar in molecular weight, they differ from each other in chromatographic behavior. P-450(3) seems to be different from P-450(1) in molecular weight, though they are similar to each other in chromatographic behavior. All the cytochrome P-450 preparations can be freed from the detergents used in the purification procedure by CM-Sephadex C-50 chromatography. Detergent-free P-450(1), P-450(2), and P-448(1) exist in aqueous solution as oligomeric aggregates.

Amino Acids↗
PubMed1980

Structure and synthesis of a lipid-containing bacteriophage. Studies on the structure of the bacteriophage PM2 nucleocapsid.

The nucleocapsid of bacteriophage PM2, prepared according to Schäfer et al. [Eur. J. Biochem. 92, 579-588 (1978)], was studied by biochemical and biophysical methods. It was not possible to isolate the lipid-free nucleocapsid. More than 95% of the lipids were associated with the nucleocapsid. The asymmetric distribution of phospholipids across the viral membrane was retained in the nucleocapsid since less than 10% of the phosphatidylethanolamine was accessible to the non-penetrable membrane probe, 2,4,6-trinitrobenzenesulfonate. Micro-dissection of the nucleocapsid with thermolysin demonstrated the asymmetric orientation of core proteins across the nucleocapsid membrane. Protein III was embedded deeply in the lipid bilayer and about 20% of the molecule extended to the exterior. Protein IV interacts with PM2 DNA and is partially in the inner leaflet of the bilayer. Small-angle X-ray scattering studies on the nucleocapsid enabled us to localize the lipid bilayer structure at radii from 20.5 nm to 24.0 nm.

Bacteriophages↗
PubMed1979

Circular dichroism spectra of purified cytochromes P-450 from rabbit liver microsomes.

Circular dichroism (CD) spectra were measured for cytochromes P-450 (P-450) purified from phenobarbital- and 3-methylcholanthrene-induced rabbit liver microsomes. No striking difference in alpha-helix content was seen between phenobarbital-induced P-450 (PB P-450) (50%), phenobarbital-induced P-448 (PB P-448) (40%) and 3-methylcholanthrene-induced P-448 (MC P-448) (45--50%) in terms of ultraviolet CD spectra. Strong negative CD spectra associated with 3-methylcholanthrene transitions for MC P-448 in the near-ultraviolet region (250--310 nm) and weaker negative CD spectra associated with Soret transitions for PBP-448 ([theta] = 50 000) and MCP-448 ([theta] = 160 000), indicated that structures of these preparations are strikingly different from each other. Reduction of P-450 and P-448 led to a remarkable decrease of the Soret CD trough, suggesting that reduction was accompanied by a striking conformational change in the vicinity of the heme. Since CO complexes of reduced P-450 and P-448 showed a CD trough and an S-shaped CD, respectively, associated with the absorption peak at 450 nm, the heme vicinities are remarkably different from each other. The CD spectra in the visible region are also discussed. It was noticed that P-420, the denatured form of P-450, exhibited no CD spectra in the Soret and visible regions.

Animals↗