Bacteria were isolated from water at Alder Slough, Oregon. Of 15 isolates grown successfully in the medium employed, 100% showed measurable uptake of Zn-65. A growth curve was established for one isolate, a gram-negative rod designated AS-1. Increasing Zn-65 uptake was found generally to correspond with increasing growth of AS-1. The optimum growth temperature for this isolate was 31°C, with very little growth at 37.5°C and 6.7°C. Growth and Zn-65 uptake occurred in a 35 ppt medium from a temperature of 31.0°C to 13.9°C but little growth and no Zn-65 uptake was observed at 8.6°C and 4.4°C. Growth and Zn-65 uptake in a 0 ppt medium occurred from 31.0°C to 5.0°C, with little growth but measurable Zn-65 uptake at 8.9°C and 5.0°C. It was found that 200 ppm Mg added to a culture which had already taken up Zn-65 failed to displace the zinc from the cells. A interaction of the energy source, Casamino Acids, with the Zn-65 spike influenced the results. When cells were lysed, spiked with Zn-65, and the debris removed by centrifugation, 84.8% of the Zn-65 remained in the supernatant. But when cells grown first in Zn-65 spiked medium were lysed and centrifuged, 74.4% of the Zn-65 was found in the debris. It was concluded that bacterial uptake of Zn-65 and other metal cations must be considered in determining the fates of these materials released into the environment. Chemical adsorption phenomena were determined to be a major factor controlling this uptake, with other chemical and biological factors, such as competitive binding by the medium and active uptake or exclusion by the cells, exerting a significant influence that requires further investigation to characterize. / Graduation date: 1971

Graduation date: 1994

Thesis (Ph. D.)--University of Washington, 1983. / Vita. Bibliography: leaves [59]-65.

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers in Taiwan. Copper-zinc superoxide dismutase (SOD1) is widely distributed and comprises 90% of the total superoxide dismutase (SOD), which catalyzes the conversion of superoxide to hydrogen peroxide. Reduced expression of antioxidant enzymes, particularly SOD1, has been identified in human hepatoma specimens and cell lines. However, it remains unclear how SOD1 expression affected the tumorigenic processes of hepatoma cells. Expression analysis of an array of human HCC cell lines revealed that SOD1 protein levels were down regulated in poorly differentiated SK-Hep-1 cells. Adenovirus-mediated SOD1 expression increased the SOD1 protein level by 30-40% of control. In addition, SOD1 gene transfer decreased the cellular O2 ¡V level yet increased the H2O2 production. SOD1 overexpression significantly reduced the proliferation, motility, and anchorage-independent growth of SK-Hep-1 cells, but had no effect on the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9. SOD1 restoration inhibited the proliferation of SK-Hep-1 cells through induction of cell cycle arrest, which was associated with decreased expression of cyclin A, cyclin D1, cdk1, cdk4 and upregulation of p21Cip1 and p27kip1. Besides, SOD1 overexpression also inhibited the nuclear factor £e B (NF-£eB) activities, thereby attenuating the proliferation and migration of SK-Hep-1 cells. In conclusion, SOD1 restoration attenuated the tumorigenicity of hepatoma cells.

We have successfully synthesized the zinc and cadmium complexes containing bis(3-trimethylsilyl-2-thiophenyl)phenylphosphine (SiPS2): [NEt4][(SiPS2)Cd(SC6H5)] (1) , [NEt4][(SiPS2)Cd(SC6H11)] (2) , [NEt4][(SiPS2)Cd(SCH2C6H5)] (3) , [NEt4][(SiPS2)Zn(SC6H5)] (4) , [NEt4][(SiPS2)Zn(SC6H11)] (5) and [NEt4][(SiPS2)Zn(SCH2C6H5)] (6) , and characterized them using 31P NMR and mass spectrum.1 and 2 were also characterized by X-ray diffraction methods. In the attemprs to get crystals of 4 and 6, we got the oxidized dimer complex 4* and 6* instead. In these complexes the two oxygen atoms of the oxidized ligands and the sulfur atom of the monodentate thiolate ligand bridge both the cadmium centers. Zinc complexes exhibit distorted tetrahedral structure. However, the cadmium ion tends to form five coordination oxidation dimeric complexes.

The treble clef binding motif of the zinc finger metalloprotein utilizes N2S2 binding sites. Whereas other N2S2 metalloproteins function in catalytic roles, zinc fingers serve mostly a structural element, although there has been some evidence that the zinc finger protein can interact with exogenous metal ions in aggregate formation or ion exchange. The work presented within has been aimed at precedents for both of the latter in Zn2+. The use of zinc and cadmium dithiolate complexes as mono- and bidentate S-donor ligands to tungsten carbonyl complexes was explored and the ability of zinc and cadmium complexes to stably bind to W(CO)x (x = 4 and 5) was established. The reactivity of thiolate sulfurs within the bimetallic complexes was examined, gaining an understanding of zinc and cadmium N2S2. The characteristics of these complexes were examined via IR, UV-vis, elemental analysis, and x-ray crystallography spectroscopy. The ability of zinc to act as a scaffold for the synthesis of bisacetylbme-dach in the production and subsequent transfer of the same ligand to exogenous metal ion sources was investigated. Cu2+ and Cd2+ analogs to the Zn-1’-Ac2 were synthesized and their properties investigated with IR, elemental analysis, and UV-vis spectroscopy.

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Thèse d'exercice : Médecine. Dermatologie - Vénéréologie : Université de Nantes : 2005. / Bibliogr. f. 89-98 [115 réf.].

Includes bibliographical references (p. 136-150).