Whole sequence of spoIIIE-like, sporulation-inhibitory, and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus and detection of spi-like gene in the actinomycete chromosome

The nucleotide sequence of spoIIIE-like and the sporulation-inhibitory and transfer gene (spi) in a conjugative plasmid, pSA1.1, of Streptomyces azureus were examined to detect the promoter region. Using Southern blotting and a spi fragment as probe, spi-like genes were detected in chromosomes of the host and other actinomycetes. These results suggest that there is a spi- and spoIIIE-like gene in chromosomes of some actinomycetes.     

Preparation of highly active Cr-catalysts for ethylene polymerization

A Cr(CH₃COO)₃ · (CH₃CO)₂O/MgCl₂/AlEt₂Cl/2-EHA catalyst was prepared by modifying the Battelle catalyst with MgCl₂ in 2-ethyl-1-hexanol(2-EHA), and the polymerization of ethylene was carried out in toluene at 20–60°C. The rate of polymerization increased to reach an individual stationary value during the course of polymerization, and the stationary rate markedly increased with an increase in the molar ratio of Mg/Cr. The polyethylene obtained without MgCl₂ had a rather low molecular weight with a very broad polydispersity, whereas those obtained in the presence of MgCl₂ had extremely high molecular weights with narrow polydispersities.Polymerization of ethylene was subsequently performed under similar conditions using various types of metal chlorides in place of MgCl₂. A clear relation was found between the polymerization activity and the electronegativity X(M^x+) of metal ion in Mclx:metal chlorides having the electronegativities below X(Cr²⁺) accelerated the activity, whereas those above X(Cr²⁺) retarded it. A plausible mechanism for the enhancement of the activity by metal chlorides was proposed on the basis of these results.     

Development of advanced power system analog simulator

The digital simulation method has been utilized to analyze phenomena in power systems. Since different algorithms can be applied, depending on the phenomena to be analyzed, digital simulation allows for high-precision analysis. However, it also has a disadvantage: it produces continuous phenomena which occur in actual systems only fragmentarily. Thus, when discussing important projects at research centers such as IREQ in Canada, an analog simulator issued to continuously analyze the phenomena from the moment the fault occurs until steady state. These analog simulators, however, consist of only a few generator models. They are only effective for analyzing phenomena in small-scale systems and do not allow for analysis of phenomena in large-scale systems over a long period of time. For this reason, the Kansai Electric Power Company (KEPCO) in cooperation with Hitachi, Ltd., and Fuji Electric Co., Ltd., has developed the world's largest power system simulator (APSA: Advanced Power System Analyzer). The simulator will be used to analyze the evolution of accidents in actual systems and to analyze continuous system phenomena over a long period. This paper describes an outline of the simulator.     

Improvement of plasma etching durability of positive working resist by copolymerization,blending, and crosslinking

The plasma etching durability of O₂ and CCl₄ was investigated for copolymer and polymer blend of poly(methyl methacrylate) (PMMA) and poly(α-methylstyrene) (PMSt) as a function of MSt content. Further, the effects of crosslinking on plasma etching were studied by incorporating N-methylolated methacrylamide into the copolymer as a crosslinkable site during prebaking. The plasma-etching resistance of PMMA was largely improved by incorporating or adding only a small amount of MSt. Especially in the case of the CCl₄ plasma etching, the copolymer and the polymer blend with 10 mol% of MSt showed etching resistance as great as that of PMSt homopolymer. Stabilization of the polymers against the plasma etching can be explained by the sponge effect, the energy migration followed by the quenching by the phenyl ring. The polymer blend offered similar etching resistance as the copolymer, indicating an effective occurrence of the energy migration between the polymer chains. Etching resistance was also improved by crosslinking, also due to the enhancement of the sponge effect.     

Clinical evaluation of Azasetron Hydrochloride: a new selective 5-HT3 receptor antagonist--antiemetic profile and plasma concentration in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma

We performed a clinical evaluation on the antiemetic profile and the plasma concentration of Azasetron Hydrochloride (a new selective 5-HT3 receptor antagonist), in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma. Antiemetic effects were examined in 32 patients in the serotone group (administration of serotone 10 mg + methylprednisolone 125 mg) and in 77 patients of the control group (administration of metoclopramide 20-30 mg + methylprednisolone 500 mg). The response rate and the CR ratio in serotone group was 97% and 66%, respectively. These results were statistically higher than in the control group. Although all patients had chronic liver diseases, no side effects and complications related to administration of serotone were observed. The average area under the concentration (AUC) curve of plasma serotone in five patients with liver cirrhosis was 531 ng.h/ml, which was greater than that of a healthy volunteer. In conclusion, serotone is a new, safe and useful antiemetic drug in TACE therapy for hepatocellular carcinoma.     

Effect of ischemic preconditioning on myocardial oxygen consumption during ischemia

Ischemic preconditioning (IPC) in the heart may reduce myocardial energy demand. The present study was undertaken to examine changes in myocardial oxygen consumption (MVO2) during ischemia by IPC in Langendorff perfused rat hearts. We assessed MVO2 during ischemia from the measurement of mitochondrial cyt. aa3 redox state by a two-wavelength reflectance spectrophotometry where T(1/2), the time from the onset of ischemia to the point for half reduction of cyt. aa3, was assumed to represent MVO2. The heart was preconditioned by three cycles of 5 min ischemia plus 5 min reperfusion and then subjected to 30 min global ischemia followed by reperfusion for 30 min. The T(1/2) was significantly longer in the preconditioned heart (30 +/- 6 s, n = 10) than the control heart (14 +/- 5 s, n = 9, P<0.001), indicating a reduction of MVO2 during ischemic period by IPC. The prolongation of T(1/2) was evident after only one IPC episode. When the heart was perfused with high K+ solution to abolish MVO2 for contractions, we still found the prolongation of T1(1/2) in the preconditioned heart (116 +/- 12 s, n = 6) compared to the control heart (86 +/- 10 s, n = 6, P<0.01), suggesting that decrease in contractile activity may be, in part but not completely, responsible for the reduction of MVO2. In contrast, the prolongation of T(1/2) was completely abolished by administration of a NO synthase inhibitor N omega-nitro-L-arginine in the high K+ arrested heart, demonstrating involvement of NO in the reduction of MVO2, presumably by suppression of mitochondrial respiratory chain. In conclusion, IPC reduces MVO2 during ischemia. The reduction of MVO2 in the preconditioned heart may be accounted for by decreased contractile activity and by depression of respiratory chain by NO.     

Two-stage arterialized flow-through venous flap transfer for third-degree burn defects on the dorsum of the hand

A modified, two-stage arteriovenous flow-through venous flap was designed to repair skin defects due to third-degree burns on the dorsum of the hand in four patients. Two weeks after plasty of an arteriovenous (A-V) shunt between the greater saphenous vein and dorsalis pedis artery, the arterialized flow-through venous flap was transferred using the greater saphenous vein as the pedicle. The size of the flaps utilized ranged from 7 x 13 cm to 9 x 13 cm. In three patients the entire flap survived without complication. In one patient whose flap had only one drainage vein, the flap survived with superficial necrosis of about 10 percent of the flap at the borders. During the 2 weeks after A-V shunt creation, the authors believe that microcirculation around the arterialized vein probably develops, contributing to better irrigation and thereby to flap survival. Using this two-stage procedure, it might be feasible to obtain larger grafts and to attain a higher flap survival rate.     

Light-emitting polymers and their LED devices

Highly luminous polymers have successfully been prepared by copolymerization of various arylene vinylene units. The random copolymerization of the monomers having different energy gaps or conjugation degrees can generate the irregularity in poly(arylene vinylenes) and enhance the fluorescence of the polymer. Among the copolymers synthesized, the m/p-phenylene vinylene copolymer showed fairly strong fluorescence and gave the most efficient polymer light-emitting diode (P-LED) device because of the good balance of the exciton confinement and the charge transporting property. The optimized P-LED device showed a maximum luminance of 70000 cd/m²