Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xvi, 176 p.; also includes graphics (some col.). Includes abstract and vita. Advisor:, Dept. of Biochemistry. Includes bibliographical references (p. 168-176).

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 154-167). Available also in a digital version from Dissertation Abstracts.

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Monoamine oxidases (MAOs) are phylogenetically old enzymes which catalyze the deamination of monoamines. Interest in a relationship between MAO and aggressive behaviour derives from the report of a single family with a mutation which obliterates the activity of MAO A, as well as a long history of studies which substantiate a relationship between MAO activity and impulsive aggressive behaviour. The goals of this thesis were: (1) to examine the generalizability of the specific MAO mutation noted above; (2) to evaluate the relationship between platelet MAO activity and genetic polymorphisms in MAO genes, and (3) to extend knowledge regarding the developmental behavioural impact of MAO deficiency in mice treated pre- and perinatally with inhibitors of MAO. / In the first study we genotyped the C936T mutation in 100 subjects followed longitudinally and oversampled for aggressive behaviour. None of the subjects in our sample carried this mutation. / In the second study, we report the lack of association between platelet MAO activity and four intronic microsatellite polymorphisms of the MAO genes. / Studies of MAO knockout mice are at significant variance with clinical pharmacological experience using MAO inhibitors. Prompted by this and by other seminal basic experiments, we hypothesized that inhibition of MAO activity during the developmental period would have profound behavioural effects. MAO A and B inhibitors were administered, separately or in combination, to mice during gestation and lactation. Total prenatal MAO inhibition produced a severe pattern of behaviour, while MAO-B inhibited mice demonstrated a similar pattern with lower intensity. Aggression was elevated in MAO-A inhibited mice only after acute pharmacological challenges suggesting prenatal sensitization. Thus developmental inhibition of MAO activity engenders behavioural effects which parallel those observed in animals devoid functional MAO. These data underscore the importance of neurochemical changes during development and provide a possible model for uninhibited aggression, common in clinical populations.

Many fish species respond to cold temperatures by inducing mitochondrial biogenesis, reflected in an increase in the activity of the mitochondrial enzyme cytochrome c oxidase (COX). COX is composed of 13 subunits, 3 encoded by mtDNA and 10 encoded by nuclear genes. I used thermal acclimation/winter acclimatization to explore how fish muscle controls the synthesis of COX. In this study, I used real-time PCR to measure mRNA levels for the 10 nuclear-encoded COX genes and several transcriptional regulators. I compared the thermal response of two cyprinid species, the tropical zebrafish (Danio rerio, acclimated to 11 and 30°C) and the temperate redbelly dace (Phoxinus eos, winter and summer acclimatized). I hypothesized that (i) there would be an increase in COX activity in the cold- versus warm-acclimated fish and (ii) changes in COX activity would be paralleled in the transcript levels of the nuclear-encoded COX subunits as well as the master-regulators and transcription factors of mitochondrial biogenesis. Zebrafish COX activity did not change in the cold but the transcript levels of some subunits decreased up to 70%. Redbelly dace COX activity was 2.9-fold higher in winter fish and though nuclear-encoded subunits had higher transcript levels the increases did not parallel enzyme activity, ranging from 1.7- to 21-fold higher in winter. There also did not appear to be parallel patterns in mRNA for the transcriptional regulators. In zebrafish, when COX activity did not change, there was no significant change in PGC-1α mRNA. In redbelly dace, when COX activity was 2.9-fold higher, PGC-1α mRNA was 6.3-fold higher. These observations suggest that coordination of COX subunit expression is imperfect, implying that subsets of these genes are more important in determining the COX activity. I assert that those genes that are most likely the candidates for regulating COX activity are COX4 and COX5A as they are the first regulatory subunits incorporated into the holoenzyme. Though arguments can also be made for COX5B, 6A and 7B based on the parallels between changes in enzyme activity and transcript abundance as well as the position in which they are assembled into the enzyme complex. / Thesis (Master, Biology) -- Queen's University, 2010-08-10 11:35:35.352

Polyphenol oxidase (PPO) enzymatic extracts were recovered from apple fruit and potato tubers and enriched by an acetone precipitation. The enriched PPO extracts were immobilized by adsorption onto a wide range of inorganic supports, including chitin, alumina oxide, glass beads, Celite, Dowex and Silica gel using selected media, including water, sodium phosphate buffer and a ternary micellar system. The highest immobilization efficiencies and specific activities were obtained when the PPO extracts were suspended in sodium phosphate buffer and adsorbed onto alumina oxide. Biocatalysis of the free and immobilized PPO extracts was investigated in selected organic solvent media, including hexane, heptane, toluene and dichloromethane, using chlorogenic acid, catechin, and the endogenous phenolic compounds from apple fruit and potato tubers as substrate models. In the organic solvent media, the free PPO extracts from apple and potato demonstrated optimal enzymatic activities at 28°C and between 25 to 35°C, respectively, whereas the immobilized extracts both showed optimal enzymatic activities at 30°C. The free and immobilized extracts from apple and potato also showed similar pH values for optimal enzymatic activity in the range of 6.0 to 6.5. The immobilized apple and potato PPO extracts demonstrated a 1.5 to 1.8 and 2.1 to 3.2-fold increases in PPO activity, respectively, compared to those observed with their free counterparts, and the lowest Km values were obtained with chlorogenic acid followed by catechin and the endogenous phenolic compounds. The immobilized and free PPOs from apple and potato also showed higher Vmax values in the hexane medium followed the heptane, toluene and dichloromethane media. The end products of PPO biocatalysis were purified by size-exclusion chromatography and detected at 280 nm for the residual catechin and endogenous phenolic compounds, and at 320 nm for the PPO-catalyzed end products. Spectroscopic scanning

Graduation date: 1992

Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 162-188). / Also available by subscription via World Wide Web / xvi, 188 leaves, bound ill. (some col.) 29 cm

Thesis (M.Sc.)--University of Adelaide, Dept. of Physiology, 1977.

Thesis (M.Sc.) --University of Adelaide, 1946. / Typewritten copy.