Rokuji Matsushita

Insulin-mimetic vanadyl—dithiocarbamate complexes

Abstract As candidates for insulin mimetics, we prepared five vanadyl—dithiocarbamate complexes with VO(S 4 ) coordination mode, and determined their structures by elemental analysis, visible absorption, IR and electron spin resonance spectra; the five complexes were bis( N,N -dimethyldithiocarbamate)oxovanadium(IV) (VO-DMD), bis( N,N -diethyldithiocarbamate)oxovanadium(IV) (VO-DED), bis(pyrrolidine- N -dithiocarbamate)oxovanadium(IV) (VO-PYD), bis( N -methyl, N ′- d -glucamine-dithiocarbamate)oxovanadium(IV) (VO-MGD) and bis(sarcosine- N -dithiocarbamate)oxovanadium(IV) (VO-SAD). The insulin-mimetic activities were evaluated by in vitro and in vivo experiments. These complexes inhibited the release of free fatty acid (FFA) from isolated rat adipocytes, similar to the action of insulin. Among them, VO-PYD and VO-SAD complexes were found to be the most effective. In addition, the VO-PYD complex promoted the incorporation of glucose in rat L6 muscle cells. Based on these in vitro observations, both VO-PYD and VO-SAD complexes were given to streptozotocin-induced diabetic rats (STZ-rats) intraperitoneally or orally. Serum glucose levels of STZ-rats dropped from hyperglycemic levels to the normal range within 1 or 2 days after both intraperitoneal and oral administrations of the complexes. To understand the insulin-mimetic action of the VO-PYD complex, the organ distribution of vanadium was investigated. In normal rats treated with VO-PYD complex, vanadium was distributed in almost all tissues, indicating that the action of vanadium is not peripheral. In addition, vanadium was found in bone and kidney when VO-PYD was given. On the basis of these results, the VO-PYD complex is indicated to be a good agent to treat insulin-dependent diabetes in experimental animals.

Preparation of dithiocarbamatecellulose derivatives and their adsorption properties for trace elements

Tosylcellulose was treated separately with aniline, benzylamine, n-butylamine and piperazine to give four different aminocelluloses which were further treated with carbon disulfide to furnish four dithiocarbamatecelluloses (AND, BZD, BUD and PID). A comparative study was made of their performance as adsorbents for several kinds of metal ions. PID, which has the highest degree of substitution of the dithiocarbamate group of the four derivatives obtained, was investigated for its adsorption behavior towards Ag+, As5+, Cd2+, Co2+, Cr3+, Cr6+, Cu2+, Fe3+, Hg2+, Mn2+, Pb2+, Sb5+; Se4+, Te4+ and Zn2+. PID showed good adsorption characteristics with relatively large capacities for Ag+, Cr6+, Cu2+, Hg2+, Pb2+ and Se4+ ranging from 9.5 to 370 mg g-1 of resin.

Gamma-ray energies of Se-85 and Se-86

The aim of the study described was to separate Se from other flssion products rapidly by paper electrophoresis, and to measure the unknown gamma -ray energies of the short-lived Se nuclides and their relative intensities. Details are given of the experimental procedure, and results are shown tabulated. (Uk)

Thermomigration of Scandium in Aluminum

The redistribution of scandium in polycrystalline A1-0.04 at ppm Sc dilute alloy which was annealed under a temperature gradient was investigated by means of the neutron activation analysis. The remarkable result is that the concentration of scandium increased at both the hot and the cold sides of specimen. Such a distribution is caused by a movement of scandium toward the both ends through the specimen. The movement of scandium toward the cold end is explained qualitatively in terms of the scandium flow associated with vacancy flow. It is pointed out that such an induced solute flow plays an important role on the thermomigration in substitutional alloys, and that the vacancy distribution under a temperature gradient should be investigated quantitatively to establish a well understanding of thermomigration in substitutional alloys.

Reactor neutron activation analysis by using multi-elemental comparators: Problems of nuclear constants of128I,175Yb and several other nuclides

A simple method has been developed for evaluating the neutron spectrum and the temperature by using U, Sb, Cr, Co and Lu as monitors and successfully applied to the routine analysis. For most of nuclides, amounts determined by the method showed reasonable agreements with those added. However, there have been found several nuclides which gave erroneous results beyond the permissible limits. In the case of128I, the reason for the deviation was found to lie on the normalization factor of γ-ray abundances that are in common use. This was confirmed by using I2 doped polyacethylene which is a material highly resistant to ionizing radiations.46Sc,175Yb and several other rare earth nuclides are discussed as well.

Annual Changes in Some Physiological Properties of Cryptomeria Japonica Leaves from Kanto, Japan

C. japonica leaves were sampled monthly in a heavily damaged area (a-I: Saitama), a slightly damaged area (a-II: plains in Ibaraki), and a healthy area (a-III: mountainous areas in Ibaraki) in Kanto. The leaves were analyzed for apparent cuticular transpiration rates, amounts of epicuticular wax, and contact angles. Sb in aerosols deposited on the leaves was also analyzed. The transpiration rates and the increase in transpiration with leaf aging were higher in a- I than in a-II and a-III. Erosion rates of the wax were higher in a-I and a-II than in a-III. The decrease of contact angles with aging tended to be higher in a-I and a-II than in a-III. Rates of aerosol-Sb deposition on the leaves were in the order a-I ≫ a-II > a-III. The transpiration rates correlated with the values obtained from a linear binomial function that included the amounts of wax and aerosol-Sb as variables (r = 0.855, P < 0.01). In a-l, the large quantity of aerosols on the leaves (and probably gaseous air pollutants) may have increased the transpiration rates by ca. 50% owing to erosion of the wax and stomatal malfunction, placing C. japonica under chronic water stress.

Determination of manganese in tissues by neutron activation analysis using an antimony pentoxide column

A rapid and accurate method is presented for the determination of manganese in biological samples, using neutron activation analysis. Biological samples were irradiated at 5000 kW for 30 min. The samples were ashed on a hot plate with 14 mol/l HNO3 and 6 mol/l HClO4, and resolved in 1 mol/l HClO4. 24Na and 24K were removed by passing each sample through in antimony pentoxide column. 54Mn was added as a tracer to calculate the ratio of manganese recovered by the separation procedure. Recovery was over 90%. This method was applied in order to determine manganese in various tissues. In the cervical spinal cord of the controls, the mean manganese concentrations in the anterior horn, the lateral and the posterior columns were 1.14, 1.06 and 0.90 ng/mg of dried tissue, respectively. In two cases if amyotrophic lateral sclerosis the manganese concentrations in the cervical spinal cord were elevated, particularly in the anterior horn and the lateral column.

Neutron flux gradients and spectrum changes in the irradiation capsule for reactor neutron activation analysis

In order to improve the accuracy of reactor neutron activation analysis, flux gradients and spectrum changes in the irradiation capsule have been studied at the Kyoto University Reactor (KUR). The flux and spectrum monitoring samples of Fe, Co, Au, Sb, U and Ni were placed at several positions in a polyethylene irradiation capsule of 24 mm inner diameter and 98 mm length, and were irradiated in a pneumatic irradiation facility (Pn-2). The flux gradients were found to be rather negligible in the vertical (axial) direction while they were considerable in the radial one. The flux gradient was around 5%/cm for thermal neutrons and 10%/cm for epithermal and fast neutrons. The spectrum changes were dependent on the materials (polyethylene and silica) filled in the capsule. Based on these observations, the effect of the flux gradients and spectrum changes on the accuracy of reactor neutron activation analysis was discussed.

Multielement compositions of marine phytoplankton samples from coastal areas of japan by instrumental neutron activation analysis

Phytoplankton samples were collected during spring bloom of diatoms from three coastal areas of Japan using a NORPAC P-25 net (25-Μm opening) with a NGG52 prenet (335-Μm opening), and 25 major and trace elements have been analyzed by INAA. Concentration ranges of analyzed phytoplankton samples are much wider than the concentration ranges compiled by Bowen (1979) except for As, and data of marine phytoplankton samples for Br, Sb, Hf, Sc, La, Ce, Sm, and Eu were not included in the compilation. The 25 analyzed elements have been categorized into three groups: elements showing positive correlation with Br, positive correlation with Al, and no positive correlation with Br or Al. The marine phytoplankton samples have been plotted on a Masuzawa-Koyama-Terazaki (MKT) plot and it proved that the MKT plot is applicable to marine phytoplankton samples.

Chemical Behavior of Carrier Free Iodine Produced by Beta-Decay and Effects of Iodine Carriers

The effect of carriers oil the chemical behavior of 131I produced from the 130Te(n, γ)13lTe 131I processes was investigated with paper electrophoresis, autoradiography and γ-ray spectrometry. If no carrier was added, the chromatograms of the iodine species revealed significant deposits of an unexpected chemical species between the spots of the iodide and iodate species. The addition of either iodate or periodate as carrier converted the species into iodate in the former case, and into iodate and periodate in the latter. Referring to the already known exchange reactions between different iodine species, hence was concluded that the species observed in the experiment without carrier was the iodite species (IO− 2), as surmised by previous authors.