Thesis (M.S.)--Duquesne University, 2003. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 99-109) and abstract.

Thesis (doctoral)--University of Stockholm, 1983. / Publications on which thesis is based are appended. Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Roberta F. Colman, Dept. of Chemistry and Biochemistry. Includes bibliographical references.

Principal objectives of my research were to: (1) report for the first time that coelomocytes are able to reduce NBT dye and confirm the presence of lysozyme-like activity in earthworm; (2) develop a standard methodology for determination of NBT reduction and lysozyme-like activity in earthworms; (3) compare NBT reduction and lysozyme-like activity in earthworms with those of murine and human cells and fluids; and (4) demonstrate the sensitivity of earthworm NBT reduction and lysozyme-like activity as the assays using matrics in refuse-derived fuel fly ash (RDFF) and CuSO4.

The cytochromes P450 (P450s) are important enzymes involved in metabolic pathways, which use exogenous and endogenous substances as their substrate for various enzymatic reactions. These enzymes can also use precarcinogens as their substrate and activate them into carcinogens, which leads to a cancer development. If the P450s are induced, the cancer risk increases. Some chemopreventive compounds may induce the P450s and thus be harmful to the human body. Therefore it is necessary to pay enough attention to a study of the mechanism of action of P450s and the influence of the chemopreventive compounds on the activity of cytochromes P450. mRNA expression of most of the P450s isoforms is detected in a number of healthy (nontransformed) tissues, viz. liver, brain, heart, colon, kidney or placenta. Nevertheless there are a few P450s isoforms which mRNAs are expressed at relatively low levels in the nontransformed tissues, whereas the expression in the transformed tissues is significantly higher. One of these P450s is CYP2W1, which can be used as a prognostic marker for colorectal cancer - therefore it is useful to be able to detect a presence of this enzyme in various tissues. A detection of P450s can be accomplished by using a method Western blot. In this method, the immunodetection is achieved by using...

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1981. / Vita. Includes bibliographical references (p. 239-262).

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 1981. / Supervised by John J. Stegeman. Vita. Includes bibliographical references (leaves 239-262).

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000. / "February, 2001." "Funding was provided by National Institute of Health grant ES-07381 and a Rinehart Coastal Research Center grant." Includes bibliographical references (p. 174-177).

Bioactivation of organohalogen xenobiotics produces reactive intermediates which alkylate macromolecules. The activation of carbon tetrachloride, trichloroethylene, and methylene chloride was studied in isolated rat hepatocytes by examining alkylation of lipid, protein, RNA, and DNA. All organohalogens alkylated lipid and protein. Carbon tetrachloride and trichloroethylene, but not methylene chloride, alkylated RNA and DNA. Methylene chloride was more highly activated in an oxygen containing atmosphere by hepatocytes, consistent with a proposed formation of formyl chloride as its reactive intermediate. Trichloroethylene was also shown to be more highly activated in an oxygen containing atmosphere, consistent with a proposed trichloroethylene epoxide reactive intermediate. Carbon tetrachloride was shown to be more highly activated in an oxygen-free atmosphere, consistent with a proposed trichloromethyl free radical reactive intermediate. Hepatocytes from rats pretreated with phenobarbital to induce cytochrome P-450 mixed function oxidase activated carbon tetrachloride and trichloroethylene to alkylating intermediates greater than did hepatocytes from non-induced rats. The interaction of carbon tetrachloride metabolites with fatty acids was studied in a chemical activation model system. The thermal decomposition of benzoyl peroxide produced free radicals which activated carbon tetrachloride. The resulting trichloromethyl free radicals abstracted a hydrogen from methyl stearate resulting in chloroform and fatty acid free radicals. Using chemical ionization mass spectrometry, it was discovered that the fatty acid free radical abstracted a chlorine from carbon tetrachloride resulting in chlorinated fatty acid esters. When methyl oleate was used as a substrate in the benzoyl peroxide model system, it was discovered that the trichloromethyl free radical binds covalently, resulting in a fatty acid adduct radical. This radical then abstracted a chlorine to produce chloro, trichloromethyl stearic acid methyl ester, identified by chemical ionization mass spectrometry. Carbon tetrachloride radiolabeled with ¹⁴C or ³⁶Cl in dual label binding experiments in the benzoyl peroxide model system confirmed the mass spectral data. Methyl stearate bound ³⁶Cl- and ¹⁴C-carbon tetrachloride in the ratio of approximately 10 to 1, whereas methyl oleate bound in the ratio of approximately 3.5 to 1. The existence of fatty acid radicals due to hydrogen abstraction or covalent binding by trichloromethyl free radicals was demonstrated in microsomal preparations. In the presence of tritiated water and ¹⁴C-carbon tetrachloride, dual-label analysis demonstrated that the tritium incorporation into microsomal lipids approximately equalled the sum of carbon tetrachloride metabolites bound covalently to microsomal lipids and chloroform production.

Graduation date: 1992