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An efficiency calibration method has been developed to measure radioactivity of volume samples with HPGe detectors. The method has two main procedures. One is a point-source calibration at a representative point near the detector. The position of the representative point is determined by Monte Carlo simulations. The other is correction for absorption by a sample matrix and a sample container. This paper presents application of the method for obtaining efficiency curves for volume samples in the energy range from 22 to 1836 keV. In addition to the standard volume sources of cement and water matrices, measurement was made with some kinds of environmental samples that are often used in environmental monitoring for radiation control works. The composition of the environmental sample was determined by elemental analysis. For these samples, measured absorption correction factors were compared with those by the Monte Carlo simulations. As a result, detection efficiency curves were obtained with good accuracy for variety types of volume samples.

We previously reported that (+/-)-6-(4-(benzylamino)-7-quinazolinyl)-4,5- dihydro-5-methyl-3(2H)-pyridazinone (+/-)-1, KF15232) showed potent cardiotonic activity with a strong myofibrillar Ca(2+)-sensitizing effect. As an extension of our work, we attempted to synthesize optically active 1. (+/-)-4-(4-(Benzylamino)-7-quinazolinyl)-3-methyl-4-oxobutyric acid (-)-menthyl ester (6) was separated into both diastereoisomers, and each was converted to optically pure 1 (99% ee) in an enantioselective manner. In order to determine the absolute configuration of the isomers, an alternative synthesis of optically active 1 was employed. The precursor of (-)-1 ((+)-9) was obtained by enantioselective synthesis from (R)-D-alanine. Consequently, we concluded that the absolute configuration of (-)-1 at the 5-position of the pyridazinone ring was R. The cardiotonic effects and inhibitory activities to PDE III and V of racemic 1 and (-)-1 were more potent than those of (+)-1. These compounds also demonstrated greater vasorelaxant effects in guinea pig aorta. In contrast, (+)-1 showed only weak cardiotonic and vasodilating effects, although the compound displayed potent Ca(2+)-sensitizing activity. Racemic and (-)-1 attracted our interest for the treatment of congestive heart failure.

MS-282a and MS-282b were isolated from the culture broth of Streptomyces tauricus ATCC 27470 as inhibitors of smooth muscle myosin light chain kinase (MLCK). MS-282a and MS-282b inhibited the activity of chicken gizzard MLCK with IC50 values of 3.8 microM and 5.2 microM, respectively. Cyclic AMP-dependent protein kinase, cyclic GMP-dependent protein kinase and protein kinase C were not inhibited by 150 microM MS-282a at all. It is likely that MS-282a blocks MLCK activity by antagonizing calmodulin since 1) the compound inhibited calmodulin-dependent but not calmodulin-independent activity of MLCK; 2) the inhibition of MLCK was antagonized by increasing concentrations of calmodulin, and 3) the compound inhibited calmodulin-dependent cyclic nucleotide phosphodiesterase.

A new xanthine oxidase inhibitor named hydroxyakalone was isolated from the culture broth of a marine bacterium Agrobacterium aurantiacum N-81106. Structure of hydroxyakalone was determined to be 4-amino-1H-pyrazolo[3, 4-d]pyrimidine-3-one-6-ol by the spectral studies of hydroxyakalone and its permethyl derivative. The concentration to induce 50% inhibition (IC50) was 4.6μM against xanthine oxidase.

By using a simple pulse shape discrimination technique, rise time spectra of α and β(γ) rays from solid sources were measured with several solid scintillators (CsI(Tl), NaI(Tl), CaF 2 (Eu), BaF 2 , BGO − , NE102A and stilbene). The best scintillator among them for resolution between α and β(γ) rays was a CsI(Tl) crystal (a figure of merit: 2.4). After the resistance of thin Au- and Al-coated Mylar films to various solutions was examined, the discrimination between α and β(γ) rays from the solutions was also proved to be feasible by measuring with the CsI(Tl) scintillators protected with the films (a figure of merit: 1.8–2.0).

The anticellular and antitumor activities of novel antitumor antibiotics, duocarmycins (DUMs), were examined against human and murine tumor cells. DUMs consist of live compounds, A, B1, B2, C1, and C2, which possess a pharmacophore similar to that of CC‐1065, a previously isolated antibiotic. Among them, DUMA exhibited ultrapotent growth‐inhibitory activity with an IC50 value of 6 pM against human uterine cervix carcinoma HeLa S3 cells. DUMA and DUMB1 also inhibited the growth of adriamycin (ADM)‐resistant lines of human nasopharynx carcinoma KB cells and breast carcinoma MCF‐7 cells as well as their sensitive lines. DUMs inhibited the growth of s.c.‐inoculated murine tumors such as B16 melanoma, sarcoma 180, M5076 sarcoma and colon 26. DUMs were also significantly effective in increasing the lifespan of i.p.‐inoculated B16 melanoma‐bearing mice, although their effect was marginal against other i.p.‐inoculated tumors. As a whole, DUMB1 exhibited superior activity to the other four compounds. DUMB1 rapidly inhibited the incorporation of [3H]‐TdR into macromolecules of HeLa S3 cells as compared with that of [3H]UR or [3H]leucine. DNA strand breaks were detected in DUMB1 ‐treated HeLa S3 cells by agarose gel electrophoresis with a contour‐clamped homogeneous electric field apparatus. These results indicate that DUMs possess interesting biological activities as DNA‐targeting antitumor antibiotics.

We investigated the basic technology of cell culture conditions for production of useful substances such as cytokines, and related proteins produced by Namalwa cells. Namalwa cells (Klein, 1972), human B lymphoblastoid cells, were used for large scale production of alpha-interferon (Klein, 1979). Namalwa KJM-1, a subline of Namalwa cells, adapted to serum- and albumin-free medium, can grow at a high density above 1 × 10(7) cells/ml in suspension mode by the use of a perfusion culture system, Biofermenter(™), containing a cone-type cell-sedimentation column as cell separator (Sato, 1983).Several kinds of cytokine cDNA can be introduced and expressed in Namalwa KJM-1 cells (Miyaji, 1990a,b,c). Some of these were produced in large quantities by use of a gene amplification method with dhfr (Miyaji, 1990c), even though the Namalwa KJM-1 cells contained endogenous dhfr genes. For stable production of the target protein, Namalwa KJM-1 cells are very useful host cells, because they have no effective endogenous protease activity in the conditioned medium.Using Biofermenter with micro-silicone fibers and a dialysis system, the specific productivity of the target proteins was not depressed at a high cell density.

A new xanthine oxidase inhibitor named hydroxyakalone was isolated from the culture broth of a marine bacterium Agrobacterium aurantiacum N-81106. Structure of hydroxyakalone was determined to be 4-amino-1H-pyrazolo[3,4-d]pyrimidine-3-one-6-ol by the spectral studies of hydroxyakalone and its permethyl derivative. The concentration to induce 50% inhibition (IC50) was 4.6 microM against xanthine oxidase.

Phoswich detectors for simultaneous counting of α, β and γ rays have been developed, which were prepared by combining two or three scintillators, ZnS(Ag), NE102A and/or BGO or NaI(TI), with different rise times from each other. In order to adjust the pulse height ascribed to each scintillator within a dynamic range, a sheet of Au—Mylar was used, if necessary, as an optical neutral density filter for lowering the transmittance of scintillation of the ZnS(Ag). Characteristics of these phoswiches were examined by a pulse shape discrimination technique. Excellent discrimination among the radiations was attained for the prepared phoswiches.

Nine azaphilones designated RP-1551-1, -2, -3, -4, -5, -6, -7, -M1, and -M2 were isolated from the culture broth of Penicillium sp. SPC-21609 as inhibitors of PDGF binding to its receptor. RP-1551s inhibit the binding of PDGF AA to the extracellular domain of PDGF alpha-receptor with IC50 values ranging from 0.1 to 2 microM without affecting PDGF BB binding to the extracellular domain of PDGF beta-receptor. PDGF binding was not restored after the PDGF alpha-receptor extracellular domain was washed in an attempt to remove the RP-1551-1 bound to the receptor. This result suggests that RP-1551-1 may irreversibly interact with the PDGF alpha-receptor. Since many azaphilone compounds possess high reactivity with an amino group, RP-1551-1 may prevent PDGF AA binding by reacting with amino groups on the alpha-receptor extracellular domain.

RES-1149-1 and -2, produced by Aspergillus sp. RE-1149, were found to be non-peptidic antagonists for endothelin type B receptor (ET(B) receptor). RES-1149-1 and -2 selectively inhibited the endothelin-1 (ET-1) binding to ET(B) receptor in a competitive manner with IC50 values of 1.5 microM and 20 microM, respectively. RES-1149-1 inhibited the increase in intracellular Ca2+ concentration elicited by 1 nM ET-1 in COS-7 cells expressing human ET(B) receptor, but not in the case of cells expressing ET(A) receptor. In addition, some structure-activity relationships are described.

A human erythroleukemia cell line, K-562 T1, was adapted to a protein-free chemically defined medium (1); that is, the medium does not contain any proteins such as exogenous hormones, growth factors, serum and serum albumin. The K-562 T1 cells which can proliferate in a protein-free medium are one of the model systems suitably supporting the autocrine hypothesis (2), which claims that cancer cells produce and respond to their own growth factors (3). The K-562 T1 cells were cultured in a protein-free medium at large scale and the growth factors were purified from the conditioned medium. It was found that K-562 T1 cells produce at least two growth factors; one is LGF-I (leukemia-derived growth factor-I) which can stimulate the proliferation of a wide range of human leukemia cell lines and the other is LGF-II (leukemia-derived growth factor-II), which can contribute to the growth of fibroblasts. LGF-I was purified using QAE-Sephadex, Bio Gel P-60 and Mono S FPLC. The purified protein was found to be homogenous by SDS-polyacrylamide gel electrophoresis and NH2-terminal sequence analysis. The molecular weight of LGF-I was 20,000 by SDS-polyacrylamide gel electrophoresis. The 30 NH2-terminal residues of LGF-I are the same as that of ubiquitin. Ubiquitin is a protein found in eukaryotic cells with molecular weight of 8,600. In the nucleus ubiquitin is conjugated to histone 2A to form the nuclear protein A24 which may play a role in regulation of chromatin structure (3), and in the cytoplasm is part of an ATP-dependent non-lysosomal proteolytic pathway (4). However, its physiological significance has not yet been fully resolved. Ubiquitin purified from bovine thymus did not show cell proliferating activity for any cells tested. The results suggest that LGF-I is a new autocrine growth factor with a molecular weight of 20,000 daltons, containing ubiquitin at the NH2-terminal end.

Glycerol oxidase, a novel glycerol oxidizing enzyme, has been found in several strains belonging to genera Aspergillus, Neurospora, and Penicillium. Aspergillus japonicus AT 008 showed significantly high enzyme activity. Glycerol oxidase was formed in the mycelia of the fungi grown on glycerol as a carbon source. The enzyme was purified from the cell-free extract of Aspergillus japonic us AT 008 by a procedure involving fractionation with ammonium sulfate, column chromatographies on DEAE-Sephadex A-25 and hydroxylapatite, and gel filtration on Sephadex G-200. The overall purification was approximately 190-fold with a yield of 35.5%. The purified enzyme gave a single band on acrylamide gel electrophoresis. The enzyme catalyzed the oxidation of glycerol using molecular oxygen as a primary electron acceptor and producing glyceraldehyde and hydrogen peroxide according to the following scheme: CH2OHCHOHCH2OH+O2 → CHOCHOHCH2OH + H2O2.

A distribution apparatus has been developed for preparing the gaseous tritium standard sources in ampoules suitable for calibration of gas-monitors. The apparatus consists of a gas handling loop for mixing and exhausting, ampoule racks and a radioactivity measurement loop.The radioactivity measurement loop contains a standard spherical glass ionization chamber which has an effective volume of 1, 210cm3. The ionization chamber was calibrated with the gaseous standard sources supplied by LMRI in France. The dependences of the ionization efficiency of a spherical ionization chamber on effective volume and internal air pressure were derived on the basis of Monte Carlo calculation. They could give a good explanation of the measured results.The standard sources prepared by this apparatus could cover the activity range from 1×10-2μCi to 1mCi. The uncertainty of the activity in an ampoule was estimated to be within ±5% in consideration of the errors of radioactivity measurement and ampoule sealing.

Thin iron crystals having the (001) plane parallel to their surfaces are prepared from zone melted iron, and 90° magnetic domain walls and black-white images appearing at the junctions of {110} 90° walls are examined by transmission X-ray topography. The topographs are taken with various reflections. The displacement of lattice points in the neighbourhood of a {110} 90° wall is in the planes parallel to the wall plane. Black-white images are formed by axially symmetrical strain fields around the junctions of {110} 90° walls. Long straight images lying in the directions in the crystal surfaces and short images in rows in the directions are found. These images are due to the strain fields around the junctions, having the directions, in the interior of the crystals. The strain fields giving rise to the black-white images are discussed in terms of the dynamical theory of diffraction contrast in deformed crystals.