Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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Objective: Breast cancer is the most common invasive cancer in women in the world. Benzo[a]pyrene (B[a]P), a carcinogenic component of cigarette smoke and grilled meat, was related to expression of enzymes involved in several epithelial malignancies including breast cancer. Understanding the association of exposure to B[a]P and breast cancer risks may inform potential disease preventive measures. The objective of this systematic review was to assess from epidemiological studies the relationship between the exposure to and the risks and development of breast cancer in humans. Study design: A systematic search using keywords in PubMed (1990-2014), CNKI (1994-2014) and Google Scholar databases was carried out to identify eligible epidemiological studies on the association between the exposure to B[alP and breast cancer risks published during 1990-2014. Results: Nine studies met the inclusion criteria and included in this review. All nine included studies used case-control design, with B[a]P exposure mainly proxied by benzo(a)pyrene diolepoxide (BPDE) and dietary consumption of B[a]P-rich food. Of these, seven found a significant positive association between B[a]P exposure and breast cancer risks, after adjustment for age, family history of breast cancer, smoking, ethnicity, alcohol use and parity in most studies. Discussion: Discuss the potential reason for inconsistence, the possible biological pathways explaining the role of B[a]P in the development of breast cancer, limitations of the studies and the public health implication from this review. Conclusion: A positive association between B[a]P exposure and breast cancer risks was suggestive from the systematic review. However given the limited number of studies included, further prospective cohort studies in humans as well as molecular/animal studies are warranted to explore the impact of B[a]P on the development of breast cancer to inform evidence based preventive measures against breast cancer. / published_or_final_version / Public Health / Master / Master of Public Health

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 102-124). Also available on the World Wide Web.

In the present study rats were pretreated with agents that are known to affect the activities of the benzo[a]pyrene (BP) metabolizing enzymes in vitro. Also, agents which are known to alter the levels of hepatic glutathione were used. These experiments were carried out in order to determine the effects of enzyme induction, enzyme inhibition, and glutathione levels on the degree of covalent binding of BP to liver macromolecules in vivo. In addition the roles of aryl hydrocarbon hydroxylase (AHH) and epoxide hydratase (EH) can be studied in this way. Since the degree of covalent binding of polycyclic aromatic hydrocarbons (PAH's) and their tumor-initiating ability have been shown to correlate (13), the factors which govern the extent of covalent binding are of major importance. When ³H-BP was administered intraperitonea11y to male Wistar rats, a certain amount of the compound was bound irreversibly to liver macromolecules. The degree of irreversible binding was found to be dependent on both the dose of BP administered and the time after its injection. The degree of binding was found to be linearly dependent on the dose of BP between the range of 0.125 and 12.5 μ moles, thereby suggesting that the metabolizing pathways of BP were not saturated at these levels. The study showed the maximum level of binding to occur at 12 to 18 hours after 1.25 μ mole of BP, and this fell to 60% of maximum by 48 hours. The BP dosage of 1.25 μ mole was employed throughout the study. The results showed that pretreating rats with SKF 525-A significantly decreased the level of irreversibly bound BP from control levels by about 30%. The decrease in binding after SKF 525-A treatment is in agreement with the evidence that the cytochrome P-450 enzymes are responsible for the activation of BP to reactive intermediates, and that they can be inhibited by this compound (42). SKF 525-A at 35 mg/kg, a dose which produces inhibition of AHH in vitro (74) did not decrease the binding of BP in vivo. SKF 525-A at 50 mg/kg or higher was required to produce a decrease in binding, indicating the necessity to reach a higher effective hepatic concentration of SKF 525-A to inhibit the irreversible binding of BP in vivo, in contrast to a lesser amount of SKF 525-A required to inhibit BP hydroxylase in vitro. Oral methadone pretreatment failed to alter the level of BP binding to liver macromolecules. Methadone was found to increase hepatic epoxide hydratase by 212% in male Wistar rats (66), but in the present study this did not have any influence on the degree of binding of BP in vivo. 3-Methy1cholanthrene (3~MC) pretreatment was found to significantly decrease the level of irreversibly bound BP from control by about 30%. The possible causes of this 3-MC induced decrease in binding are discussed. One possibility is that the 3-MC induced decrease could be due to an alteration in the pathways of BP metabolism. The existence in the liver of various forms of cytochrome P-450 (39) along with the evidence that 3-MC induces a spectrally distinct cytochrome P-448 (40,58) could suggest that 3-MC alters BP metabolism to sites on the BP molecule that produce less reactive intermediates, and thereby decreases the degree of binding. Neither xysteine nor diethyl maleate pretreatment altered the level of irreversibly bound BP from control. The data obtained from these experiments can be explained by one or more of the following mechanisms: no significant depletion of glutathione by BP occurs, there is a lack of a glutathione threshold level for binding to take place, or there is a drastically different role for glutathione than its role in the protection of hepatic macromolecules from alkylation by active metabolites of acetaminophen. The enzyme-mediated binding of BP to liver macromolecules in vitro and its inhibition by methadone, SKF 525-A, 3-MC, glutathione, and cysteine was demonstrated and the relevance of these findings towards the present experiments was discussed. Throughout the study a second population of animals showed binding of BP that was both qualitatively and quantitatively different from the first. The percentage of animals that fell into this 2nd population was 19% (46 out of 250) of all the animals used in the study. / Pharmaceutical Sciences, Faculty of / Graduate

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by Ho, Kai-Man. / Thesis submitted in: December 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 158-179). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstracts --- p.ii / Contents --- p.vii / List of figures --- p.xiv / List of tables --- p.xvii / Abbreviations --- p.xx / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Poly cyclic Aromatic Hydrocarbons (PAHs) / Chapter 1.1.1 --- Characteristics of PAHs --- p.1 / Chapter 1.1.2 --- Sources of PAHs --- p.3 / Chapter 1.1.3 --- Environmental fates of PAHs --- p.5 / Chapter 1.1.4 --- Effects of PAHs on living organisms --- p.7 / Chapter 1.1.5 --- Summary --- p.10 / Chapter 1.2 --- Target PAH: Benzo[a]pyrene (BaP) --- p.10 / Chapter 1.3 --- PAH contamination in Hong Kong --- p.14 / Chapter 1.4 --- Remediation for PAHs contaminated soils --- p.15 / Chapter 1.4.1 --- Chemical/ Physical methods --- p.15 / Chapter 1.4.2 --- Bioremediation --- p.16 / Chapter 1.5 --- Biodegradation of PAHs by bacteria and fungi --- p.18 / Chapter 1.5.1 --- Tolerance and degradation --- p.18 / Chapter 1.5.2 --- Biodegradation of PAHs by microorganisms --- p.20 / Chapter 1.5.2.1 --- Bacteria --- p.22 / Chapter 1.5.2.2 --- Fungi --- p.23 / Chapter 1.6 --- Environmental standards --- p.26 / Chapter 1.7 --- Strategies of soil sampling and microbial isolation --- p.26 / Chapter 1.7.1 --- Contaminated soil vs. uncontaminated soil --- p.26 / Chapter 1.7.2 --- Native species vs. foreign species --- p.29 / Chapter 1.7.3 --- Background of the sampling areas --- p.30 / Chapter 1.7.3.1 --- North Tsing Yi shipyard --- p.30 / Chapter 1.7.3.2 --- "Tsam Chuk Wan, Sai Kung" --- p.33 / Chapter 1.8 --- Objectives of this study --- p.33 / Chapter 2. --- Materials and Methods --- p.35 / Chapter 2.1 --- Soil Collection --- p.35 / Chapter 2.1.1 --- Abandoned shipyard soil and its sediment soil --- p.35 / Chapter 2.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.35 / Chapter 2.2 --- Characterization of soils --- p.35 / Chapter 2.2.1 --- Sample preparation --- p.36 / Chapter 2.2.2 --- Soil pH --- p.36 / Chapter 2.2.3 --- Electrical conductivity --- p.36 / Chapter 2.2.4 --- Salinity --- p.36 / Chapter 2.2.5 --- Total organic carbon contents --- p.38 / Chapter 2.2.6 --- Metal analys --- p.is / Chapter 2.2.7. --- Oil and grease content --- p.38 / Chapter 2.2.8 --- Soil texture --- p.39 / Chapter 2.2.9 --- Available ammoniacal nitrogen and oxidized nitrogen --- p.39 / Chapter 2.2.10 --- Available Phosporus --- p.40 / Chapter 2.2.11 --- Total Nitrogen and total Phosporus --- p.40 / Chapter 2.2.12 --- Moisture / Chapter 2.2.13 --- DTPA-extractable metals --- p.41 / Chapter 2.2.14 --- Extraction of PAHs and organic pollutants --- p.41 / Chapter 2.2.14.1 --- Extraction procedures --- p.41 / Chapter 2.2.14.2 --- GC-MSD conditions --- p.41 / Chapter 2.2.14.3 --- Extraction efficiency --- p.43 / Chapter 2.2.15 --- Soil colour --- p.43 / Chapter 2.3 --- Screening and selection of microorganismms --- p.43 / Chapter 2.3.1 --- Isolation of potential BaP-degrading microorganisms --- p.44 / Chapter 2.3.1.1 --- Isolation of bacteria --- p.44 / Chapter 2.3.1.2 --- Isolation of fungi --- p.44 / Chapter 2.3.2 --- Cultures preserving microorganisms --- p.46 / Chapter 2.3.3 --- Screening and selection of microbes --- p.46 / Chapter 2.3.3.1 --- Bacteria --- p.46 / Chapter 2.3.3.2 --- Fungi --- p.46 / Chapter 2.3.4 --- Survival test --- p.47 / Chapter 2.3.5 --- Removal efficiency (RE) towards BaP by the microorganisms --- p.47 / Chapter 2.3.5.1 --- Bacteria --- p.47 / Chapter 2.3.5.2 --- Fungi --- p.48 / Chapter 2.3.6 --- Removal efficiency (RE) --- p.48 / Chapter 2.3.7 --- Relationship of absorbance of bacterial culture and bacterial biomass --- p.49 / Chapter 2.4 --- Identification of selected microorganisms --- p.49 / Chapter 2.4.1 --- Identification of bacterium --- p.49 / Chapter 2.4.1.1 --- 16S rDNA sequencing --- p.49 / Chapter 2.4.1.1.1 --- Primers --- p.49 / Chapter 2.4.1.1.2 --- DNA extraction --- p.51 / Chapter 2.4.1.1.3 --- Specific PCR --- p.51 / Chapter 2.4.1.1.4 --- Gel electrophoresis --- p.51 / Chapter 2.4.1.1.5 --- Purification of PCR products --- p.52 / Chapter 2.4.1.1.6 --- DNA sequencing --- p.52 / Chapter 2.4.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.53 / Chapter 2.4.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.55 / Chapter 2.4.2 --- Identification of fungi --- p.56 / Chapter 2.4.2.1 --- ITS DNA sequencing --- p.56 / Chapter 2.4.2.2 --- Observation under electronic microscope --- p.58 / Chapter 2.5 --- Growth curve of the microorganism --- p.58 / Chapter 2.5.1 --- Bacterium --- p.58 / Chapter 2.5.2 --- Fungi --- p.58 / Chapter 2.6 --- Preparation of Benzo[a]pyrene (BaP) stock solution --- p.58 / Chapter 2.7 --- Comparison of isolated bacterium and fungi --- p.60 / Chapter 2.8 --- Optimization of BaP degradation by selected fungus --- p.60 / Chapter 2.8.1 --- Preparation of straw compost inoculated with selected fungus --- p.60 / Chapter 2.8.2 --- Effect of incubation time --- p.61 / Chapter 2.8.3 --- Effect of initial BaP concentration --- p.61 / Chapter 2.8.4 --- Effect of inoculum size / Chapter 2.8.5 --- Effect of temperature --- p.61 / Chapter 2.8.6 --- Effect of soil pH --- p.62 / Chapter 2.8.7 --- Study of BaP degradation pathway by the microorganisms using GC-MSD --- p.62 / Chapter 2.9 --- Chitin Assay --- p.62 / Chapter 2.10 --- Enzyme assay --- p.63 / Chapter 2.10.1 --- Laccase assay --- p.63 / Chapter 2.10.2 --- Manganese peroxidase assay --- p.63 / Chapter 2.10.3 --- Lignin peroxidase assay --- p.64 / Chapter 2.11 --- Toxicity of treated soil --- p.64 / Chapter 2.12 --- Statistical analysis --- p.65 / Chapter 3. --- Results --- p.66 / Chapter 3.1 --- Soil Collection --- p.66 / Chapter 3.1.1 --- North Tsing Yi shipyard --- p.66 / Chapter 3.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.66 / Chapter 3.2 --- Characterization of soil samples --- p.71 / Chapter 3.3 --- Extraction efficiency of Benzo[a]pyrene --- p.79 / Chapter 3.4 --- Screening and selection of microorganisms --- p.79 / Chapter 3.4.1 --- Isolation ofpotential BaP-degrading microorganisms --- p.79 / Chapter 3.4.2 --- Screening and selection of microbes --- p.87 / Chapter 3.4.2.1 --- Bacteria --- p.87 / Chapter 3.4.2.2 --- Fungi --- p.93 / Chapter 3.4.3 --- Growth curve of the microorganisms --- p.95 / Chapter 3.4.3.1 --- Bacterium --- p.95 / Chapter 3.4.3.2 --- Fungi --- p.99 / Chapter 3.5 --- Comparison of isolated bacterium and fungi --- p.99 / Chapter 3.6 --- Identification of selected microorganisms --- p.102 / Chapter 3.6.1 --- Identification of bacterium --- p.103 / Chapter 3.6.1.1 --- 16S rDNA sequencing --- p.103 / Chapter 3.6.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.103 / Chapter 3.6.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.107 / Chapter 3.6.2 --- Identification of fungi --- p.107 / Chapter 3.6.2.1 --- ITS DNA sequencing --- p.107 / Chapter 3.6.2.2 --- Observation under electronic microscope --- p.113 / Chapter 3.7 --- Optimization of BaP degradation by the selected fungus: Trichoderma asperellum --- p.107 / Chapter 3.7.1 --- Effect of incubation time --- p.107 / Chapter 3.7.2 --- Effect of inoculum size --- p.113 / Chapter 3.7.3 --- Effect of initial BaP concentration --- p.113 / Chapter 3.7.4 --- Effect of soil pH --- p.113 / Chapter 3.7.5 --- Effect of temperature --- p.117 / Chapter 3.8 --- Determination of breakdown products of BaP by BaP-degrading microorganisms --- p.117 / Chapter 3.9 --- Enzyme assay --- p.117 / Chapter 3.10 --- Evaluation of toxicity by using indigenous bacteria --- p.121 / Chapter 4. --- Discussion --- p.128 / Chapter 4.1 --- Physico-chemical properties of soil samples --- p.128 / Chapter 4.2 --- Determination of BaP and other organic compounds --- p.131 / Chapter 4.3 --- Identification of the microorganisms --- p.132 / Chapter 4.3.1 --- Bacteria --- p.132 / Chapter 4.3.2 --- Fungi --- p.134 / Chapter 4.4 --- Biodegradation by BaP-degrading microorganisms --- p.135 / Chapter 4.4.1 --- Isolation and screening of BaP-degrading microorganisms --- p.135 / Chapter 4.4.2 --- Biodegradation of BaP --- p.137 / Chapter 4.4.2.1 --- Bacteria --- p.137 / Chapter 4.4.2.2 --- Fungi --- p.138 / Chapter 4.4.3 --- BaP degradation pathway --- p.140 / Chapter 4.4.3.1 --- Bacteria --- p.140 / Chapter 4.4.3.2 --- Fungi --- p.140 / Chapter 4.5 --- Optimization of PAH degradation by T. asperellum --- p.143 / Chapter 4.5.1 --- Effect of incubation time --- p.143 / Chapter 4.5.2 --- Effect of initial BaP concentration --- p.144 / Chapter 4.5.3 --- Effect of inoculum size fungus --- p.144 / Chapter 4.5.4 --- Effect of soil pH --- p.145 / Chapter 4.5.5 --- Effect of temperature --- p.146 / Chapter 4.6 --- Comparison the selected bacterium and fungi --- p.146 / Chapter 4.7 --- Evaluation of toxicity by using in indigenous bacteria --- p.148 / Chapter 4.8 --- Post treatment by crude enzyme of Pleurotus pulmonarius --- p.149 / Chapter 4.9 --- Limiting factors for BaP degradation --- p.150 / Chapter 4.10 --- Further Investigations --- p.152 / Chapter 5. --- Conclusion --- p.155 / Chapter 6. --- References --- p.158

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Rhode Island, 2004. / Typescript. Includes bibliographical references (leaves 220-233).

No description available.