• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 152
  • 107
  • 63
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 299
  • 299
  • 299
  • 104
  • 103
  • 55
  • 46
  • 39
  • 37
  • 37
  • 33
  • 28
  • 28
  • 26
  • 25
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Perspectives on healthcare, chronic noncommunicable disease and healthworlds in an urban and rural setting

Ibanez-Gonzalez, Daniel Lopes 25 August 2014 (has links)
Background: This study is located within a complex network of paradigmatical methodological, and institutional relationships, and draws concepts from a range of scholastic traditions. The hermeneutical tradition within Sociology, particularly as exemplified in the work of Jurgen Habermas, provides a starting point for exploring and interpreting the experiences of chronic illness and healthcare access. The concept of the lifeworld/ healthworld as a description of the complex of health beliefs and behaviours of individuals in relation to the ailing body is used to describe chronic illness and healthcare access, both as lived experience and as fields for public health intervention. Aim: To understand how women living with chronic illness experience their illness and access healthcare in an urban and rural context. Methods: This study is a mixed-methods comparative case study of the healthcare access experiences of women with chronic illness in an urban and rural area in South Africa. The core of the study methodology is a comparative qualitative case study, with quantitative methods serving to contextualise the findings. The urban component of the study was conducted in Birth to Twenty (Bt20), a birth cohort study located in Johannesburg-Soweto. The rural component of the study was conducted in Agincourt, a sub-district of the Bushbuckridge district in Mpumalanga Province. The quantitative context for the Soweto case study uses secondary data collected by Bt20 to construct a historical overview of the use of formal and informal healthcare services in Soweto. It also uses the findings of a large scale cross sectional survey of the primary caregivers of the Bt20 cohort, conducted between November 2008 and June 2010. The rural case study is contextualised by a detailed review of research conducted in the Agincourt sub-district. For the qualitative case studies I employed a qualitative methodology incorporating serial narrative interviews to present an experience-based overview of concepts of disease causation, self treatment and coping. Results: The cross-sectional survey describes a low resource population with a high prevalence of chronic noncommunicable disease (NCDs). Over one third (37.3%) of the population in Soweto could be categorised as having a low socio-economic status, defined as access to only one or less of 5 socio-economic items. Slightly over half the respondents in Soweto (50.7%) reported having at least one chronic illness. Only around a third (33.3%) of the survey participants with chronic illnesses reported accessing formal healthcare services in the last 6 months. Similar trends were found in the review of research carried out in Agincourt. The qualitative case study in Soweto is characterised by a preoccupation with how the medicine from the clinic interacts with the body. The search for alternative remedies took place not as an attempt to cure disease, but to reach a deeper understanding of the diseased state of the body. The Agincourt qualitative case study highlights the importance of church membership, particularly of African Christian Churches, as the strongest factor motivating against the open use of traditional medicine. In both study sites there is evidence that traditional healers were consulted for social purposes rather than health-related purposes. Discussion: Soweto and Agincourt share similar patterns of healthcare utilisation and healthcare belief. Both study sites were characterised by increasing trends in formalisation. At the same time, only a small portion of individuals in both study sites with chronic illness utilised formal healthcare services. A consideration of the findings suggests five broad themes for further research: (1) Processes of constructing body narratives; (2) Encounters with purposive-rational systems; (3) Encounters with traditional medicine; (4) Encounters with contemporary informal medicine; and (5) Religion and healthcare. These five themes constitute the beginning of a comprehensive map of the lifeworld/ healthworld schema. Such a schema has implications for healthcare policy and practice, particularly with regard to the development of integrative paradigms in South Africa as exemplified by Community Oriented Primary Care (COPC). Conclusion: The aims and objectives of the study were met through the development of an initial lifeworld/ healthworld schema, which suggests that the coexistence of diverse public healthcare concerns of high NCD prevalence and low formal healthcare utilisation is best addressed through the adoption of integrated healthcare approaches based on lifeworld/ healthworld rationalistion.
112

Mechanisms underlying chemopreventive effect of celecoxib in gastric carcinogenesis.

January 2006 (has links)
Chu Wai Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-96). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / Publication --- p.iii / List of Abbreviations --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Abstract --- p.vii / 摘要 --- p.x / Table of Contents --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Epidemiology of gastric cancer --- p.1 / Chapter 1.2 --- Risk factors associated with gastric cancer --- p.7 / Chapter 1.3 --- Prevention of Gastric Cancer --- p.9 / Chapter 1.4 --- H. pylori eradication and gastric cancer development --- p.11 / Chapter 1.5 --- Non-steroidal anti-inflammatory drugs and gastric cancer prevention --- p.13 / Chapter 1.6 --- COX-2 independent pathway --- p.14 / Chapter 1.7 --- Animal model of gastric cancer --- p.15 / Chapter 1.8 --- Microarray system --- p.16 / Chapter 1.9 --- Hypothesis --- p.18 / Chapter 1.10 --- Aim of study --- p.19 / Chapter Chapter 2 --- Chemoprevention of gastric cancer by celecoxib --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Material and Methods --- p.22 / Chapter 2.2.1 --- Animals --- p.22 / Chapter 2.2.2 --- Chemicals --- p.22 / Chapter 2.2.3 --- Study design --- p.23 / Chapter 2.2.4 --- Cell Culture --- p.24 / Chapter 2.2.5 --- Celecoxib treatment --- p.24 / Chapter 2.2.6 --- Cell proliferation assay --- p.25 / Chapter 2.3 --- Results --- p.26 / Chapter 2.3.1 --- Chemoprevention of gastric cancer by celecoxib in rats --- p.26 / Chapter 2.3.2 --- Effects of celecoxib on growth of human gastric cancer cells --- p.29 / Chapter 2.4 --- Discussion --- p.30 / Chapter 2.4.1 --- MNNG induced gastric cancer effectively --- p.30 / Chapter 2.4.2 --- Celecoxib significantly suppressed gastric carcinogenesis in rats --- p.31 / Chapter 2.4.3 --- Celecoxib inhibited the growth of MKN 45 in a concentration-dependent manner --- p.31 / Chapter 2.4.4 --- Celecoxib may exert its anti-tumor property through COX independent pathway --- p.32 / Chapter Chapter 3 --- Gene expression profiles of celecoxib treated rat gastric tumor and human gastric cells --- p.34 / Chapter 3.1 --- Introduction --- p.34 / Chapter 3.2 --- Material and Methods --- p.34 / Chapter 3.2.1 --- RNA extraction --- p.34 / Chapter 3.2.2 --- Target preparation and Array hybridization --- p.35 / Chapter 3.2.3 --- Post-hybridization processing and Scanning --- p.36 / Chapter 3.2.4 --- Microarray data analysis --- p.36 / Chapter 3.2.5 --- Quantitative RT-PCR --- p.37 / Chapter 3.3 --- Results --- p.39 / Chapter 3.3.1 --- Gene expression profiles of rat gastric tumors --- p.39 / Chapter 3.3.1.1 --- Genes differentially expressed in MNNG induced gastric tumors --- p.39 / Chapter 3.3.1.2 --- Genes differentially expressed in celecoxib treated group --- p.42 / Chapter 3.3.1.3 --- Mechanisms underlying chemoprevention of celecoxib --- p.43 / Chapter 3.3.2 --- Verification of gene expression by quantitative RT-PCR --- p.55 / Chapter 3.3.3 --- Confirmation of the gene expression profiles in human by quantitative RT-PCR --- p.59 / Chapter 3.4 --- Discussions --- p.63 / Chapter Chapter 4 --- Effects of celecoxib on Akt pathway in gastric cancer cells --- p.68 / Chapter 4.1 --- Introduction --- p.68 / Chapter 4.2 --- Material and methods --- p.72 / Chapter 4.2.1 --- Protein extraction --- p.72 / Chapter 4.2.2 --- Western blotting --- p.72 / Chapter 4.3 --- Results --- p.74 / Chapter 4.3.1 --- Expression of the Akt pathway after treatment with celecoxib --- p.74 / Chapter 4.4 --- Discussions --- p.78 / Chapter Chapter 5 --- Conclusion --- p.82 / References --- p.87
113

Effects of thrombopoietin on the protection against doxorubicin-induced cardiotoxicity.

January 2006 (has links)
To Man Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 85-105). / Abstracts in English and Chinese. / Abstract (in English) --- p.i / (in Chinese) --- p.iv / Acknowledgements --- p.vi / Publications --- p.viii / Table of Contents --- p.ix / List of Tables --- p.xii / List of Figures --- p.xiii / List of Abbreviations --- p.xiv / Chapter CHAPTER 1: --- General Introduction --- p.1 / Chapter Section 1.1 --- Background and Clinical Application of Anthracylines --- p.1 / Chapter Section 1.2 --- DOX-induced Cardiotoxicity --- p.3 / Chapter 1.2.1 --- Types of Cardiotoxicity --- p.4 / Chapter 1.2.1.1 --- Acute Cardiotoxicity --- p.4 / Chapter 1.2.1.2 --- Chronic Cardiotoxicity --- p.5 / Chapter 1.2.2 --- Subcellular Effects of DOX --- p.6 / Chapter 1.2.2.1 --- Ultrastructural Lesions --- p.6 / Chapter 1.2.2.2 --- Effects on Mitochondrial Functions --- p.7 / Chapter 1.2.2.3 --- Effects on Sarcoplasmic reticulum (SR) Functions --- p.8 / Chapter Section 1.3 --- Mechanisms of DOX-induced Cardiotoxicity --- p.8 / Chapter 1.3.1 --- Formation of Free Radicals --- p.9 / Chapter 1.3.1.1 --- Generation of Free Radicals by DOX --- p.10 / Chapter 1.3.1.2 --- Cardiac damage by Free radicals --- p.12 / Chapter 1.3.2 --- Induction of Apoptosis --- p.14 / Chapter 1.3.2.1 --- Characteristics and Pathway of Apoptosis --- p.14 / Chapter 1.3.2.2 --- Mitochondria and Apoptosis --- p.15 / Chapter 1.3.2.3 --- Caspases and Apoptosis --- p.17 / Chapter 1.3.2.4 --- Apoptosis and DOX-induced Cardiotoxicity --- p.18 / Chapter Section 1.4 --- Strategies to Reduce DOX-induced Cardiotoxicity --- p.19 / Chapter 1.4.1 --- Dosage optimization and Schedule modification --- p.19 / Chapter 1.4.2 --- Anthracycline Analogues --- p.21 / Chapter 1.4.3 --- Cardioprotective Agents --- p.21 / Chapter Section 1.5 --- Thrombopoietin --- p.23 / Chapter CHAPTER 2: --- Hypotheses and Objectives --- p.30 / Chapter CHAPTER 3: --- Methodology --- p.33 / Chapter Section 3.1 --- Methods --- p.33 / Chapter 3.1.1 --- Culture of Rat H9C2 Myoblast Cell Line and Primary Neonatal Rat Cardiomyocytes --- p.33 / Chapter 3.1.1.1 --- Maintenance of Cell Line --- p.33 / Chapter 3.1.1.2 --- Culture of Primary Neonatal Rat Cardiomyocytes --- p.34 / Chapter 3.1.2 --- Effects of Thrombopoietin on Cell Viability of Rat H9C2 Myoblast Cell Line and Beating Rates of Primary Rat Cardiomyocytes --- p.35 / Chapter 3.1.2.1 --- Cell Viability assay --- p.35 / Chapter 3.1.2.2 --- Beating Rate of Primary Beating Cardiomyocytes --- p.36 / Chapter 3.1.3 --- Effects of Thrombopoietin on the Protection against DOX-induced Heart Injury In Vivo --- p.36 / Chapter 3.1.3.1 --- Animals --- p.36 / Chapter 3.1.3.2 --- Experimental Protocol --- p.37 / Chapter 3.1.3.3 --- Echocardiography --- p.38 / Chapter 3.1.3.4 --- Blood Cell Counts --- p.39 / Chapter 3.1.3.5 --- Histopathology --- p.39 / Chapter 3.1.4 --- Effects of Thrombopoietin on Apoptosis and Mitochondrial Integrity of Rat H9C2 Myoblast Cell Line and Apoptosis In Vivo --- p.40 / Chapter 3.1.4.1 --- Determination of Externalized Phosphatidylserine --- p.40 / Chapter 3.1.4.2 --- Determination of Active Caspase-3 Expression --- p.41 / Chapter 3.1.4.3 --- Assessment of Mitochondrial Integrity --- p.42 / Chapter 3.1.4.4 --- TUNEL assay --- p.43 / Chapter 3.1.5 --- Statistical Analysis --- p.44 / Chapter CHAPTER 4: --- Effects of Thrombopoietin on Cell Viability of Rat H9C2 Myoblast Cell Line and Beating Rates of Primary Neonatal Rat Cardiomyocytes --- p.46 / Chapter Section 4.1 --- Results --- p.46 / Chapter 4.1.1 --- Effects of TPO on DOX-induced Cell Death --- p.46 / Chapter 4.1.2 --- Effects of TPO on the Beating Rates of Primary Cardiomyocytes --- p.47 / Chapter Section 4.2 --- Discussion --- p.47 / Chapter CHAPTER 5: --- Effects of Thrombopoietin on the Protection Against DOX-induced Heart Injury In Vivo --- p.54 / Chapter Section 5.1 --- Results --- p.54 / Chapter 5.1.1 --- General Observations and Survival --- p.54 / Chapter 5.1.2 --- Blood Cell Counts --- p.55 / Chapter 5.1.3 --- Cardiac Functions by Echocardiography --- p.56 / Chapter 5.1.4 --- Gross Anatomic Changes and Pathology of the Myocardium --- p.57 / Chapter Section 5.2 --- Discussion --- p.58 / Chapter CHAPTER 6: --- Effects of Thrombopoietin on Apoptosis and Mitochondrial Integrity of H9C2 Cell Line and Apoptosis In Vico --- p.69 / Chapter Section 6.1 --- Results --- p.69 / Chapter 6.1.1 --- Determination of Externalized Phosphatidylserine --- p.69 / Chapter 6.1.2 --- Determination of Active Caspase-3 Activity --- p.70 / Chapter 6.1.3 --- Assessment of Mitochondrial Membrane Potential --- p.70 / Chapter 6.1.4 --- Determination of Apoptosis by TUNEL assay --- p.72 / Chapter Section 6.2 --- Discussion --- p.72 / Chapter CHAPTER 7: --- General Discussion and Conclusion --- p.83 / References --- p.85
114

A percepção da vulnerabilidade à doença entre mulheres com diagnóstico avançado do câncer do colo do útero / The perception of the vulnerability to the disease among women with delayed diagnosis of uterine cervical cancer

Pimentel, Angela Vieira 10 June 2010 (has links)
Estudo transversal, descritivo e exploratório, com abordagem metodológica qualitativa, cujo objetivo foi identificar e avaliar a percepção da vulnerabilidade à doença, entre mulheres com diagnóstico avançado do câncer do colo do útero, tendo como referencial teórico, a vulnerabilidade, baseada no conceito proposto por Ayres et al. (2003). Os sujeitos do estudo foram doze mulheres que estavam em atendimento no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, para tratamento do câncer do colo do útero avançado, entre 08 de abril e 28 de maio de 2009. Os dados foram coletados por entrevistas. A análise dos dados se deu segundo os pressupostos da análise de conteúdo, proposta por Bardin (2006). Os resultados revelaram-se em 2 categorias centrais: Percebendo-se vulnerável e Enfrentando a doença e o tratamento. A vulnerabilidade se apresentou para as participantes deste estudo a partir do aparecimento dos primeiros sinais e sintomas da doença, crescendo à medida que o diagnóstico foi descoberto e o tratamento se fez necessário, trazendo dificuldades e sofrimento. Ao mesmo tempo, proporcionou a oportunidade de as mulheres encontrarem formas de enfrentamento e superação dos problemas, à medida do possível. Os componentes individual, social e programático da vulnerabilidade, contidos no conceito proposto por Ayres et al. (2003), mostraram-se nos fatores relacionados à cliente, aos profissionais, aos serviços, entre outros, e tornaram a mulher suscetível aos problemas e danos de sua saúde, relativos ao câncer cérvico-uterino, exacerbando sua vulnerabilidade à doença. Ficou clara a necessidade de se superar algumas deficiências no modelo de assistência e na humanização do atendimento, no grau de compromisso e na qualidade das instituições, dos recursos, do gerenciamento e do monitoramento dos programas de prevenção e detecção do câncer do colo do útero, nos diferentes níveis de atenção. / This cross-sectional, descriptive, exploratory and qualitative study aimed to identify and evaluate the perception of the vulnerability to the disease among women with delayed diagnosis of uterine cervical cancer. The theoretical framework used was the vulnerability, based in the concept proposed by Ayres et al. (2003). The subjects of the study were twelve women who were under follow-up at the Hospital das Clínicas of the University of São Paulo at Ribeirão Preto Medical School, for treatment of advanced uterine cervical cancer, between April 08th and May 28th 2009. Data were collected by interviews. The data analysis was done according to the presuppositions of content analysis, proposed by Bardin (2006). Two central categories emerged from the results: Perceiving yourself vulnerable and Facing the disease and the treatment. The vulnerability arose to the participants of this study through the emergence of the first signs and symptoms of the disease, increasing as the diagnosis was determined and treatment was needed, bringing difficulties and suffering. At the same time, women had the opportunity to find ways to face and overcome problems, to the extent possible. The individual, social and programmatic compounds of the vulnerability, included in the concept proposed by Ayres et al. (2003), were shown in the factors related to clients, professionals and services, among others, and made the women susceptible to the problems and damages of their health, related to the uterine cervical cancer, aggravating their vulnerability to the disease. The need to overcome some deficiencies in the model of care and in the humanization of care was evidenced, as well as in the level of commitment and in the quality of the institutions, resources, management, and monitoring of the programs of prevention and detection of uterine cervical cancer, in the different levels of care.
115

Modulation of cytochrome P4501A1/1B1 and UDP-glucuronosyltransferase activities by hydroxychalcones and monoterpenes.

January 2003 (has links)
Wang Huan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 148-158). / Abstracts in English and Chinese. / TABLE OF CONTENTS --- p.I / LIST OF FIGURES AND TABLES --- p.VIII / ABSTRACT --- p.1 / 摘要 --- p.3 / Chapter CHAPTER 1 --- GENERAL INTRODUCTION / Chapter I. --- The essential factors related to cancer --- p.5 / Chapter a. --- Carcinogens --- p.5 / Chapter b. --- Carcinogenesis pathways --- p.7 / Chapter c. --- DNA adducts formation and breast cancer --- p.7 / Chapter II. --- Cytochrome P450 I enzyme family --- p.8 / Chapter a. --- CYP450 superfamily --- p.8 / Chapter b. --- CYP1A1 --- p.10 / Chapter c. --- CYP1B1 --- p.11 / Chapter III. --- Transactivation of CYP1 enzymes by aryl hydrocarbon receptor (AhR) --- p.12 / Chapter IV. --- Phase II enzyme UGT and cancer prevention --- p.13 / Chapter V. --- Estrogen metabolism and the hormone-dependent breast cancer --- p.15 / Chapter a. --- Estrogen and breast cancer initiation --- p.15 / Chapter b. --- Estrogen Receptor (ER) --- p.15 / Chapter c. --- Estradiol hydroxylation pathways --- p.15 / Chapter VI. --- Phytochemicals and cancer prevention --- p.18 / Chapter VII. --- Outline of this study --- p.20 / Chapter CHAPTER 2 --- MATERIALS AND METHODS / Chapter I. --- Chemicals --- p.21 / Chapter II. --- Cell culture and treatments --- p.21 / Chapter 1. --- Maintenance of cells --- p.21 / Chapter 2. --- Preparation of cell stock --- p.22 / Chapter 3. --- Cell recovery from liquid nitrogen stock --- p.22 / Chapter 4. --- Measurement of cell viability --- p.22 / Chapter 5. --- Preparation of cell lysates --- p.23 / Chapter 6. --- XRE-luciferase gene reporter assay --- p.23 / Chapter a. --- Transient transfection of cell using lipofectamine PLUS reagent --- p.23 / Chapter b. --- Dual Luciferase Assay --- p.24 / Chapter III. --- Enzyme Activities --- p.24 / Chapter 1. --- Isolation of microsomes --- p.24 / Chapter 2. --- EROD activities in intact cells --- p.24 / Chapter 3. --- EROD inhibition assay --- p.25 / Chapter IV. --- Manipulation of Nuclear Acid --- p.26 / Chapter 1. --- Preparation of transfected DNA --- p.26 / Chapter a. --- Separation and purification of DNA from agarose gel --- p.26 / Chapter b. --- Restriction digestion --- p.26 / Chapter c. --- Ligation of DNA fragments --- p.27 / Chapter d. --- Transformation of DH5a --- p.27 / Chapter e. --- Small scale plasmid purification from DH5a (mini prep) --- p.28 / Chapter f. --- Large scale plasmid isolation from DH5a (maxi-prep) --- p.28 / Chapter g. --- Construction of XRE activated luciferase reporter gene --- p.29 / Chapter 2. --- Measurement of DMBA-DNA adduct formation --- p.29 / Chapter 3. --- Semi-quantitative RT-PCR Assay --- p.30 / Chapter a. --- Isolation of RNA using TRIzol® Reagent --- p.30 / Chapter b. --- RT-PCR --- p.31 / Chapter V. --- Phase II enzyme-UGT activity assay --- p.32 / Chapter VI. --- HPLC for estradiol-hydroxylation analysis --- p.33 / Chapter 1. --- HPLC condition for hydroxyestradiol separation and measurement --- p.33 / Chapter 2. --- Determination of microsomal estradiol hydroxylase activity --- p.34 / Chapter 3. --- Assay of estradiol metabolism in MCF-7 cells --- p.34 / Chapter VII. --- Statistical Analysis --- p.35 / Chapter CHAPTER 3 --- CHALCONES ANTAGONIZE DMBA-INDUCED CARCINOGENESIS BY MODULATION OF CYP1A1/1B1 AND UGT ACTIVITIES / Chapter Part One --- Introduction --- p.36 / Chapter Part Two --- Results --- p.40 / Chapter Section One --- Chalcones antagonize DMBA carcinogenesis by inhibiting CYP1A1 and CYP1B1 activities --- p.40 / Chapter I. --- Chalcones inhibited DMBA-induced EROD activities in MCF-7 cells --- p.40 / Chapter II. --- Inhibition of chalcones on microsomal CYP1A1 & 1B1 enzyme activities --- p.43 / Chapter III. --- Reduction of DMBA-induced DNA adduct by chalcones --- p.52 / Chapter IV. --- Chalcones antagonized CYP1A1 XRE transactivation --- p.54 / Chapter V. --- Chalcones suppressed DMBA-induced CYP1 gene expression --- p.56 / Chapter Section Two --- Chalcones modulate DMBA carcinogenesis by regulating UGT activities --- p.63 / Chapter I . --- Chalcones regulated UGT1A1 gene expression in MCF-7 cells --- p.63 / Chapter II. --- Chalcones affected UGT enzyme activity in HepG2 cells --- p.70 / Chapter III. --- Chalcones regulated UGT1A1 gene expression in HepG2 cells --- p.73 / Chapter Part Three --- Discussion --- p.80 / Chapter I . --- Chalcones are potential chemopreventive agents --- p.80 / Chapter II. --- Chalcones modulated Phase I enzyme activities --- p.80 / Chapter III. --- Chalcones regulated Phase II enzyme activities --- p.82 / Chapter IV. --- Chalcones suppressed DMBA-induced DNA-adduct formation in MCF-7 cells --- p.82 / Chapter V. --- The anti-carcinogenic properties of chalcones and their structures --- p.83 / Chapter CHAPTER 4 --- EFFECTS OF PERILLYL ALCOHOL AND LIMONENE ON CYP1 AND UGT ENZYMES / Chapter Part One --- Introduction --- p.85 / Chapter Part Two --- Results --- p.87 / Chapter I. --- Perillyl alcohol and limonene modulated DMBA-induced CYP1A1/1B1 activities in MCF-7 cells --- p.87 / Chapter II. --- Perillyl alcohol and limonene regulated microsomal CYP1A1/1B1 activities --- p.89 / Chapter III. --- Perillyl alcohol and limonene regulated DMBA-induced DNA adduct formation in MCF-7 cells --- p.93 / Chapter IV. --- Perillyl alcohol and limonene regulated CYP1A1 & CYP1B1 gene expressions in MCF-7 cells --- p.95 / Chapter V. --- Effect of perillyl alcohol on CYP1A1 XRE transactivation --- p.97 / Chapter VI. --- Cytotoxic effect of perillyl alcohol and limonene on MCF-7 cells --- p.98 / Chapter VII. --- Perillyl alcohol and limonene modulated UGT1A1 gene expression in MCF-7 cells --- p.99 / Chapter VIII. --- Perillyl alcohol and limonene modulated UGT enzyme in HepG2 cells --- p.101 / Chapter Part Three --- Discussion --- p.106 / Chapter CHAPTER 5 --- LYCOPENE MEDIATED DMBA-INDUCED PHASE I & PHASE II ENZYME ACTIVITIES AND GENE EXPRESSIONS / Chapter Part Three --- Introduction --- p.109 / Chapter I. --- Biochemical properties of lycopene --- p.109 / Chapter II. --- Bioavailability of lycopene --- p.110 / Chapter III. --- Lycopene and cancers in hormonal sensitive tissues --- p.110 / Chapter Part Two --- Results --- p.111 / Chapter I . --- Lycopene modulated DMBA-induced CYP1A1/1B1 activities in MCF-7 cells --- p.111 / Chapter II. --- Lycopene competitively inhibited microsomal CYP1A1 & CYP1B1 activities --- p.113 / Chapter III. --- Lycopene suppressed DMBA-induced DNA adduct formation in MCF-7 cells --- p.115 / Chapter IV. --- Lycopene regulated CYP1A1 & CYP1B1 gene expression in MCF-7 cells --- p.116 / Chapter V. --- Effect of lycopene on CYP1A1 XRE trasactivation --- p.117 / Chapter VI. --- Cytotoxic effect of lycopene on MCF-7 cells --- p.118 / Chapter VII. --- Lycopene modulated UGT enzyme in MCF-7 cells --- p.119 / Chapter VIII. --- Lycopene modulated UGT enzyme in HepG2 cells --- p.121 / Chapter Part Three --- Discussion --- p.123 / Chapter CHAPTER 6 --- CHALCONES AND PERILLYL ALCOHOL REGULATEDCYP1A1 & CYP1B1 MEDIATED ESTRADIOL METABOLIZING PATHWAYS / Chapter Part One --- Introduction --- p.125 / Chapter I . --- Estrogen hydroxylation and human breast cancer risk --- p.125 / Chapter II. --- CYP1 enzymes catalyze estradiol-hydroxylation in human breast cancer cells --- p.126 / Chapter III. --- Phytochemicals mediate estrogen-hydroxylation pathways --- p.126 / Chapter Part Two --- Estrogen metabolite detection and separation by HPLC --- p.127 / Chapter Part Three --- Results --- p.129 / Chapter I . --- Perillyl alcohol modulated CYP1A1 & CYP1B1-mediated Estradiol hydroxylation --- p.129 / Chapter II. --- Kinetics assays of chalcones on CYP1A1 & CYP1B1 microsomes induced estradiol hydroxylation --- p.131 / Chapter III. --- Chalcones suppressed Estradiol-hydroxylase activities in MCF-7 cells --- p.137 / Chapter Part Four --- Discussion --- p.140 / Chapter CHAPTER 7 --- SUMMARY / Chapter I . --- Chalcones displayed inhibitory effects on DMBA-induced carcinogenesis --- p.142 / Chapter II. --- Perillyl alcohol and limonene modulated DMBA-induced carcinogenesis --- p.143 / Chapter III. --- Lycopene also possessed chemoproventive properties --- p.143 / APPENDIX 1 ABBREVIATIONS --- p.144 / APPENDIX 2 REAGENTS --- p.145 / APPENDIX 3 PRIMER LISTS --- p.147 / REFERENCE --- p.148
116

Disinfection of Legionella pneumophila by photocatalytic oxidation.

January 2005 (has links)
Cheng Yee Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 95-112). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.vi / List of Figures --- p.xi / List of Plates --- p.xiv / List of Tables --- p.xvi / Abbreviations --- p.xviii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Legionella pneumophila --- p.1 / Chapter 1.1.1 --- Bacterial morphology and ultrastructure --- p.2 / Chapter 1.1.2 --- Microbial ecology and natural habitats --- p.4 / Chapter 1.1.2.1 --- Association with amoeba --- p.5 / Chapter 1.1.2.2 --- Association with biofilm --- p.5 / Chapter 1.2 --- Legionnaires' disease and clinical significance --- p.6 / Chapter 1.2.1 --- Epidemiology --- p.6 / Chapter 1.2.1.1 --- Worldwide distribution --- p.6 / Chapter 1.2.1.2 --- Local situation --- p.7 / Chapter 1.2.2 --- Clinical presentation --- p.7 / Chapter 1.2.3 --- Route of infection and pathogenesis --- p.8 / Chapter 1.2.4 --- Diagnosis --- p.10 / Chapter 1.2.4.1 --- Culture of Legionella --- p.10 / Chapter 1.2.4.2 --- Direct fluorescent antibody (DFA) staining --- p.13 / Chapter 1.2.4.3 --- Serologic tests --- p.13 / Chapter 1.2.4.4 --- Urine antigen testing --- p.14 / Chapter 1.2.4.5 --- Detection of Legionella nucleic acid --- p.15 / Chapter 1.2.5 --- Risk factors --- p.15 / Chapter 1.2.6 --- Treatment for Legionella infection --- p.16 / Chapter 1.3 --- Detection of Legionella in environment --- p.16 / Chapter 1.4 --- Disinfection methods --- p.17 / Chapter 1.4.1 --- Physical methods --- p.19 / Chapter 1.4.1.1 --- Filtration --- p.19 / Chapter 1.4.1.2 --- UV-C irradiation --- p.20 / Chapter 1.4.1.3 --- Thermal eradication (superheat-and-flush) --- p.21 / Chapter 1.4.2 --- Chemical methods --- p.21 / Chapter 1.4.2.1 --- Chlorination --- p.21 / Chapter 1.4.2.2 --- Copper-silver ionization --- p.22 / Chapter 1.4.3 --- Effect of biofilm and other factors on disinfection --- p.23 / Chapter 1.5 --- Photocatalytic oxidation (PCO) --- p.24 / Chapter 1.5.1 --- Generation of strong oxidants --- p.24 / Chapter 1.5.2 --- Disinfection mechanism(s) --- p.27 / Chapter 1.5.3 --- Major factors affecting the process --- p.28 / Chapter 2. --- Objectives --- p.30 / Chapter 3. --- Materials and Methods --- p.31 / Chapter 3.1 --- Chemicals --- p.31 / Chapter 3.2 --- Bacterial strains and culture --- p.31 / Chapter 3.3 --- Photocatalytic reactor --- p.33 / Chapter 3.4 --- PCO efficacy tests --- p.33 / Chapter 3.5 --- PCO sensitivity tests --- p.35 / Chapter 3.6 --- Optimisation of PCO conditions --- p.35 / Chapter 3.6.1 --- Optimization of TiO2 concentration --- p.36 / Chapter 3.6.2 --- Optimization of UV intensity --- p.36 / Chapter 3.6.3 --- Optimization of depth of reaction mixture --- p.36 / Chapter 3.6.4 --- Optimization of stirring rate --- p.37 / Chapter 3.6.5 --- Optimization of initial pH --- p.37 / Chapter 3.6.6 --- Optimization of treatment time and initial cell concentration --- p.37 / Chapter 3.6.7 --- Combinational optimization --- p.37 / Chapter 3.7 --- Transmission electron microscopy (TEM) --- p.38 / Chapter 3.8 --- Fatty acid profile analysis --- p.40 / Chapter 3.9 --- Total organic carbon (TOC) analysis --- p.42 / Chapter 3.10 --- UV-C irradiation --- p.44 / Chapter 3.11 --- Hyperchlorination --- p.44 / Chapter 3.12 --- Statistical analysis and replication --- p.45 / Chapter 3.13 --- Safety precautions --- p.45 / Chapter 4. --- Results --- p.46 / Chapter 4.1 --- Efficacy test --- p.46 / Chapter 4.2 --- PCO sensitivity --- p.47 / Chapter 4.3 --- Optimization of PCO conditions --- p.48 / Chapter 4.3.1 --- TiO2 concentration --- p.48 / Chapter 4.3.2 --- UV intensity --- p.48 / Chapter 4.3.3 --- Depth of reaction mixture --- p.51 / Chapter 4.3.4 --- Stirring rate --- p.56 / Chapter 4.3.5 --- Effect of initial pH --- p.56 / Chapter 4.3.6 --- Effect of treatment time and initial concentrations --- p.56 / Chapter 4.3.7 --- Combinational effects --- p.63 / Chapter 4.4 --- Transmission electron microscopy (TEM) --- p.66 / Chapter 4.4.1 --- Morphological changes induced by PCO --- p.66 / Chapter 4.4.2 --- Comparisons with changes caused by UV-C irradiation and chlorination --- p.67 / Chapter 4.5 --- Fatty acid profile analysis --- p.71 / Chapter 4.6 --- Total organic carbon (TOC) analysis --- p.73 / Chapter 4.7 --- UV-C irradiation --- p.74 / Chapter 4.8 --- Hyperchlorination --- p.74 / Chapter 5. --- Discussion --- p.76 / Chapter 5.1 --- Efficacy test --- p.76 / Chapter 5.2 --- PCO sensitivity --- p.76 / Chapter 5.3 --- Optimization of PCO conditions --- p.77 / Chapter 5.3.1 --- Effect of TiO2 concentration --- p.77 / Chapter 5.3.2 --- Effect of UV intensity --- p.78 / Chapter 5.3.3 --- Effect of depth of reaction mixture --- p.79 / Chapter 5.3.4 --- Effect of stirring rate --- p.79 / Chapter 5.3.5 --- Effect of initial pH --- p.80 / Chapter 5.3.6 --- Effect of treatment time and initial concentrations --- p.81 / Chapter 5.3.7 --- Combinational effect --- p.82 / Chapter 5.4 --- Transmission electron microscopy (TEM) --- p.83 / Chapter 5.4.1 --- Morphological changes induced by PCO --- p.83 / Chapter 5.4.2 --- Comparisons with changes caused by UV-C irradiation and chlorination --- p.85 / Chapter 5.5 --- Fatty acid profile analysis --- p.85 / Chapter 5.6 --- Total organic carbon (TOC) analysis --- p.86 / Chapter 5.7 --- Comparisons of the three disinfection methods --- p.88 / Chapter 6. --- Conclusion --- p.91 / Chapter 7. --- References --- p.95 / Chapter 8. --- Appendix --- p.113
117

Molecular mechanisms of cell death and cell cycle arrest mediated by cardiac glycosides in cancer cells. / CUHK electronic theses & dissertations collection

January 2012 (has links)
強心苷是一類多年普遍用於心力衰竭治療的化合物,包括蟾蜍靈和地高辛。鈉泵(也可稱為鈉鉀ATP酶)是強心苷的受體。最近流行病學研究,體外實驗,動物實驗和臨床試驗表明,強心苷具有癌症治療的強大潛力。 / 大腸癌是全球第三大殺手,約有一半的大腸癌患者需要手術切除後的輔助治療。因此,通過化療殺死腫瘤細胞,是一個可行的辦法來治療大腸癌患者。在本課題的研究中,強心苷抗人結腸癌的作用在HT-29和Caco-2細胞上進行了評價與闡釋。在結腸癌細胞研究模型中,蟾蜍靈誘導caspase非依賴性的細胞死亡,伴隨沒有早期凋亡,沒有聚(ADP-核糖)聚合酶(PARP)與caspase-3裂解,這些發現與強心苷誘發其它類腫瘤細胞凋亡的機製完全不同。相反,蟾蜍靈激活自噬途徑,促進LC3-II積累和自噬流動。此外,其它強心苷如地高辛與烏本苷也促使LC3-II在HT-29細胞內聚集。沉默ATG5和Beclin-1顯著降低蟾蜍靈誘導的LC3- II積累和細胞死亡。蟾蜍靈誘導的自噬與活性氧(ROS)產生和JNK活化相關。我們的研究結果揭示了蟾蜍靈藥物對抗結腸癌細胞的一種新的機制,開闢了強心苷通過自噬途徑來治療大腸癌的可能性。 / 最近的研究表明,強心苷誘導多種癌細胞系的細胞包括促使凋亡與自噬的細胞週期阻滯在G2/M期。然而,沒有詳細的信息闡述強心苷如何阻滯細胞週期進展。在本課題研究中,我們研究了強心苷介導的細胞週期阻滯的分子機制。蟾蜍靈處理的HeLa H2B-YFP細胞被阻滯在前中期,伴隨姐妹染色單體凝聚,染色體未排列在赤道板,未退出有絲分裂期。這一結果被蟾蜍靈誘導的四倍DNA含量細胞既不在四倍體G1期也不在胞質分裂期進一步證明。此後,我們檢測了紡錘體組裝和染色體分離所需的Aurora激酶和Polo-like kinase 1 (Plk1)。結果發現,在HT-29和HeLa細胞上,蟾蜍靈和其它強心苷能顯著降低總蛋白質和磷酸化的Aurora激酶與Plk1。此外,我們還發現,蟾蜍靈通過PI3K下調有絲分裂酶的活性。這些結果已經通過沉默鈉泵α做了驗證。總之,我們的結果表明, 蟾蜍靈和其它強心苷鈉鉀泵抑製劑強有力的抑制細胞在前中期是通過PI3K/HIF-1α/NF-κB途徑下調Aurora激酶的蛋白質和磷酸化水平和Plk1的蛋白質水平。我們的研究發現在了解如何利用強心苷的潛能治療癌症以及認知鈉泵在細胞週期中的功能方面提供了有用的信息。 / The sodium pump (also known as Na+/K+-ATPase) is the receptor for cardiac glycosides, a group of compounds including bufalin and digoxin which have been commonly used for heart failure treatment for many years. Recent epidemiological studies, in vitro studies, animal studies and clinical trials have shown that cardiac glycosides have potential applications for cancer treatment. / Colorectal cancer is the third leading cause of cancer death worldwide and about half of the patients with colorectal cancer require adjuvant therapy after surgical resection. Therefore, the eradication of cancer cells via chemotherapy constitutes a viable approach to treat patients with colorectal cancer. In this study, the effects of cardiac glycosides were evaluated and characterized in HT-29 and Caco-2 human colon cancer cells. Contrary to their well documented apoptosis-promoting activity in other cancer cells, bufalin did not cause caspase-dependent cell death in colon cancer cells, as indicated by the absence of significant early apoptosis, as well as poly(ADP-ribose) polymerase (PARP) and caspase-3 cleavage. Instead, bufalin activated an autophagy pathway, as characterized by the accumulation of LC3-II and the stimulation of autophagic flux. Moreover, other cardiac glycosides digoxin and ouabain could also induce the accumulation of LC3-II in HT-29 cells. The silencing of ATG5 and Beclin-1 significantly reduced bufalin-induced LC3-II accumulation and cell death. The induction of autophagy by bufalin was linked to the generation of reactive oxygen species (ROS) and JNK activation. My findings unveil a novel mechanism of drug action by bufalin in colon cancer cells and open up the possibility of treating colorectal cancer by cardiac glycosides through an autophagy pathway. / Recent studies have revealed that cardiac glycosides induce G2/M phase arrest in many cancer cells, which include apoptosis- and autophagy-promoting cells. However, no detailed information is available on how cardiac glycosides arrest cell cycle progression. In this study, I studied the molecular mechanisms of cell cycle arrest mediated by cardiac glycosides. Bufalin-treated HeLa H2B-YFP cells were arrested at prometaphase, as characterized by the presence of sister chromatid cohesion, absence of chromosomes alignment on the metaphase plate, and failure to exit mitosis. This result was further confirmed by bufalin-induced cells with 4N DNA content in neither tetraploid G1 phase nor cytokinesis. Thereafter, I detected the Aurora kinases and Polo-like kinase 1 (Plk1), which are required for both spindle assembly and chromosome segregation. It was found that bufalin and other cardiac glycosides could significantly reduce the total protein and phosphorylation of Aurora kinases and Plk1 in HT-29 and HeLa cells. In addition, I found that PI3K was responsible for the bufalin-induced downregulation of the activities of mitotic kinases. This result was validated by silencing of sodium pump alpha. Taken together, my results demonstrate that bufalin and other cardiac glycoside inhibitors of the sodium pump potently arrest cancer cells at prometaphase by downregulating the total protein and phosphorylation of Aurora kinases and the total protein of Plk1 through the PI3K/HIF-1α/NF-κB pathway. My findings provide useful information in understanding how cardiac glycosides could be exploited for their potentials in treating cancer and in identifying the function of sodium pump in cell cycle progression. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Xie, Chuanming. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 133-152). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Declaration of Originality --- p.i / Acknowledgements --- p.iii / Abstract --- p.vi / Abstract (in Chinese) --- p.viii / List of Abbreviations --- p.xiv / List of Figures --- p.xvi / List of Tables --- p.xix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Cancer --- p.1 / Chapter 1.2 --- The chemical structure of cardiac glycosides --- p.2 / Chapter 1.3 --- The traditional use of cardiac glycosides in cardiology --- p.4 / Chapter 1.4 --- The role of cardiac glycosides in cancer treatment --- p.4 / Chapter 1.5 --- The mechanisms of action by cardiac glycosides in cancer --- p.5 / Chapter 1.5.1 --- The structure and functions of cardiac glycosides receptor sodium pump --- p.5 / Chapter 1.5.2 --- Sodium pump as anticancer target --- p.6 / Chapter 1.5.3 --- The signal pathways involved in anticancer effect of cardiac glycosides --- p.7 / Chapter 1.6 --- The role of cardiac glycosides in apoptosis and autophagy --- p.8 / Chapter 1.7 --- Objectives of this project --- p.12 / Chapter Chapter 2 --- Bufalin induces autophagy but not apoptosis in human colon cancer cells --- p.17 / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- Materials and Methods --- p.19 / Chapter 2.2.1 --- Reagents and antibodies --- p.19 / Chapter 2.2.2 --- Cell culture --- p.19 / Chapter 2.2.3 --- Cell viability and cell death assay --- p.20 / Chapter 2.2.4 --- Annexin V and PI staining --- p.20 / Chapter 2.2.5 --- Cell cycle analysis --- p.21 / Chapter 2.2.6 --- Analysis of cleaved caspase-3-positive cells by flow cytometry --- p.21 / Chapter 2.2.7 --- Western blot analysis --- p.21 / Chapter 2.2.8 --- Immunofluorescence analysis of LC3 distribution --- p.22 / Chapter 2.2.9 --- RNA isolation and RT-PCR --- p.22 / Chapter 2.2.10 --- siRNAs transfection and treatments --- p.23 / Chapter 2.2.11 --- Transmission electron microscopy --- p.23 / Chapter 2.2.12 --- Statistical analysis --- p.24 / Chapter 2.3 --- Results --- p.24 / Chapter 2.3.1 --- Bufalin induces cell death and cell cycle arrest at G2/M phase in colon cancer cells --- p.24 / Chapter 2.3.2 --- Bufalin induces caspase-independent cell death in colon cancer cells --- p.28 / Chapter 2.3.3 --- Bufalin induces autophagy in colon cancer cells --- p.30 / Chapter 2.3.4 --- Bufalin-induced autophagy is dependent on ATG5 and Beclin-1 --- p.37 / Chapter 2.3.5 --- Increased autophagy is responsible for bufalin-induced cell death --- p.40 / Chapter 2.4 --- Discussion --- p.42 / Chapter Chapter 3 --- Bufalin mediates autophagic cell death through ROS generation and JNK activation --- p.44 / Chapter 3.1 --- Introduction --- p.44 / Chapter 3.2 --- Materials and Methods --- p.46 / Chapter 3.2.1 --- Reagents and antibodies --- p.46 / Chapter 3.2.2 --- Cell culture --- p.47 / Chapter 3.2.3 --- Cell viability and cell death assay --- p.47 / Chapter 3.2.4 --- Western blot analysis --- p.47 / Chapter 3.2.5 --- Quantification of cells with > 5 LC3 punctate staining --- p.47 / Chapter 3.2.6 --- siRNAs transfection and treatments --- p.48 / Chapter 3.2.7 --- RNA isolation and RT-PCR --- p.48 / Chapter 3.2.8 --- ROS analysis --- p.48 / Chapter 3.2.9 --- JC-1 staining --- p.49 / Chapter 3.2.10 --- Statistical analysis --- p.49 / Chapter 3.3 --- Results --- p.50 / Chapter 3.3.1 --- Bufalin induces autophagy-mediated cell death via ROS generation --- p.50 / Chapter 3.3.2 --- Activation of JNK is required for the upregulation of ATG5 and Beclin-1, and subsequent autophagy-mediated cell death in response to bufalin --- p.54 / Chapter 3.3.3 --- ROS generation is upstream of JNK activation in bufalin-induced cell death --- p.59 / Chapter 3.3.4 --- Bufalin-induced ROS generation is derived from mitochondria --- p.62 / Chapter 3.4 --- Discussion --- p.66 / Chapter Chapter 4 --- Bufalin arrests cells at prometaphase --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.2 --- Materials and Methods --- p.70 / Chapter 4.2.1 --- Reagents and antibodies --- p.70 / Chapter 4.2.2 --- Cell synchronization --- p.70 / Chapter 4.2.3 --- Mitotic index analysis of phosphorylation of MPM2 --- p.71 / Chapter 4.2.4 --- Cell cycle analysis --- p.71 / Chapter 4.2.5 --- Time-lapse experiments --- p.71 / Chapter 4.2.6 --- Immunofluorescence analysis of phospho-histone H3 (Ser10) --- p.72 / Chapter 4.2.7 --- Western blot analysis --- p.73 / Chapter 4.3 --- Results --- p.73 / Chapter 4.3.1 --- Bufalin reduces mitotic marker phosphorylation of histone H3 and MPM2 and increases cells with 4N DNA content --- p.73 / Chapter 4.3.2 --- Increased cells with 4N DNA content after bufalin treatment are in neither a tetraploid G1 phase nor a cytokinesis arrest --- p.77 / Chapter 4.3.3 --- Bufalin-treated cells can enter prophase, but fail to pass through metaphase --- p.80 / Chapter 4.4 --- Discussion --- p.83 / Chapter Chapter 5 --- Bufalin induces prometaphase arrest through downregulating mitotic kinases --- p.87 / Chapter 5.1 --- Introduction --- p.87 / Chapter 5.2 --- Materials and Methods --- p.89 / Chapter 5.2.1 --- Reagents and antibodies --- p.89 / Chapter 5.2.2 --- Cell synchronization --- p.90 / Chapter 5.2.3 --- Immunofluorescence staining --- p.90 / Chapter 5.2.4 --- siRNAs transfection and treatments --- p.91 / Chapter 5.2.5 --- Western blot analysis --- p.91 / Chapter 5.2.6 --- Statistic analysis --- p.91 / Chapter 5.3 --- Results --- p.92 / Chapter 5.3.1 --- Bufalin downregulates Aurora A and B in protein and phosphorylation levels --- p.92 / Chapter 5.3.2 --- Bufalin prevents Aurora A recruitment to mitotic centrosomes and Aurora B recruitment to unattached kinetochores --- p.97 / Chapter 5.3.3 --- Bufalin prevents Plk1 recruitment to mitotic centrosomes and unattached kinetochores through downregulation of protein levels of Plk1 --- p.101 / Chapter 5.3.4 --- Bufalin decreases the activities of Aurora A, Aurora B and Plk1 through PI3K pathway --- p.105 / Chapter 5.3.5 --- HIF-1α and NF-κB pathways are involved in sodium pump-mediated the regulation of mitotic kinases --- p.109 / Chapter 5.4 --- Discussion --- p.112 / Chapter Chapter 6 --- General discussion --- p.115 / Chapter 6.1 --- Potential toxicity of bufalin --- p.115 / Chapter 6.2 --- Cardiac glycosides induced programmed cell death --- p.115 / Chapter 6.3 --- Signal pathways involved in cardiac glycosides-mediated autophagy --- p.117 / Chapter 6.4 --- The relationship between ROS and JNK in cardiac glycosides-induced autophagy --- p.120 / Chapter 6.5 --- The role of ROS in apoptosis and autophagy --- p.121 / Chapter 6.6 --- The role of cardiac glycosides in cell cycle arrest --- p.122 / Chapter 6.7 --- Application of cardiac glycosides in combination with chemotherapy and radiotherapy --- p.125 / Chapter Chapter 7 --- Conclusions and future perspectives --- p.127 / References --- p.133 / Appendices --- p.153 / Publication --- p.153
118

Towards prevention of sport-related ankle sprain injury: from epidemiology study, aetiology and mechanism analysis, to the design of an intelligent sprain-free sports shoe. / CUHK electronic theses & dissertations collection

January 2008 (has links)
After investigating the injury mechanism, this dissertation aims to design an intelligent sprain-free sports shoe for the prevention of sport-related ankle sprain injury. It consists of a three-step mechanism: (1) Sensing, (2) Identification, and (3) Correction. The progress of this dissertation covers two options of sensing and identification. The first option is to monitor the ankle spraining motion with the ankle inversion angle. A method to employ two tiny inertial and magnetic sensors at the shank and foot segment is adopted as the sensing system. A laboratory study is conducted to obtain ankle inversion magnitude and velocity during various sport motions. Together with the article kinematics reported in the accidental sprain case report, a standard for identifying ankle sprain is established. The second option is to monitor the ankle spraining motion with the ankle supination torque. A feasible method to estimate the complete ground reaction forces with the information from pressure insoles is presented. Then, a tiny in-shoe three-pressure-sensor system is devised to monitor the ankle supination torque during sport motions. With the information of failure torque at the ankle joint reported by previous cadaveric study, an identification system of the ankle supination torque is devised. / Ankle sprain injury is the most common single type of sport-related musculoskeletal trauma which causes rupture and tear to the anterior talofibular ligament and ankle instability. In this dissertation, a new paradigm, "Orthopaedic Sport Biomechanics", is proposed to present the role of biomechanics in the practice of orthopaedics sports medicine, including the analysis of injury mechanism, and the design of prophylactic equipment for injury prevention. To directly investigate the injury, a case report of an accidental injury event in laboratory is presented. It was found that an internally rotated ankle orientation at foot strike may predispose the ankle joint to a supination sprain injury, by triggering lateral drift of the rearfoot and the subsequent vigorous inversion. At injury, the ankle joint reached an inversion of 48 degrees and an internal rotation of 10 degrees. / Future studies on the sensing and identification process, the correction, and the final evaluation are suggested. We hope that we could really invent the sprain-free shoe to help reducing the incidence of ankle sprain injury in sports in future. / Fong, Tik Pui Daniel. / Adviser: Kai-Ming Chan. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3635. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 102-127). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
119

Comparing the effectiveness of different strategies for primary prevention of cardiovascular diseases through anti-hypertensive drugs. / 降壓藥物進行心臟血管疾病初級預防的不同策略的效果的比較研究 / CUHK electronic theses & dissertations collection / Xiang ya yao wu jin xing xin zang xue guan ji bing chu ji yu fang de bu tong ce lüe de xiao guo de bi jiao yan jiu

January 2010 (has links)
Conclusions: In the same number of people treated, the number of CVD events avoided for the overall risk approach is always larger than that of the blood pressure approach. The additional benefits of overall risk approach compared with the blood pressure approach decreases as the percentage of people from the total population is increased. If the current practice and hypertension guidelines in China are shifted to the overall risk approach, many more CVD events could be avoided with the same resources used. / Methods: The sample used in the analyses includes a subsample of 38,673 persons from the 2002 China National Nutrition and Health Survey, who were 30-74 years old, without previous CVD, and had data on all major CVD risk factors. CVD risks of the patients selected by each approach are predicted using suitable risk prediction equation. The RRR of anti-hypertensive drug treatment derived from meta-analyses of RCTs. The difference in the absolute effectiveness between the two approaches is used to quantify how many more CVD events can be prevented in 1000 people treated by the ORA as compared to the BPA. / Objective: To estimate and compare the number of major cardiovascular events that could be avoided by shifting the blood pressure approach to the overall risk approach if the same percentage of people in a large, representative Chinese population is treated with anti-hypertensive drugs. / Results: When 2.5%, 5.5%, 10.1%, 15.5%, 20.7%, 25.7% or 33.0% of the 38,673 subjects were treated by anti-hypertensive drugs by using the two approaches respectively, 22 (95%CI: 17∼28), 13 (11∼16), 9 (8∼10), 7 (6∼8), 6 (5∼7), 5 (4∼6), or 4 (3∼4) more CVD events could be avoided in every 1000 people treated if the blood pressure approach is shifted to the overall risk approach, which is in general a 15% to 25% increase in CVD events prevented. / Qin, Ying. / Adviser: Jin Ling Tang. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 116-121). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
120

A rice bran polyphenol, cycloartenyl ferulate, triggers caspase-dependent apoptosis in human colon cancer cells. / CUHK electronic theses & dissertations collection

January 2009 (has links)
Findings from this pioneer study demonstrate that CF, which is unique to rice bran oil, is capable of triggering apoptosis in CRC cells at early stages of carcinogenesis. Furthermore, CF enhances TRAIL-induced apoptosis in metastatic CRC cells. This study provides clear evidence that the health-beneficial properties of whole grain consumption are not only limited by the presence of dietary fiber but also other molecules that can either act as a chemopreventive agent to directly induce tumor regression or a sensitizer to enhance TRAIL-induced apoptosis in metastatic cancer cells. / High intake of whole grain food has been suggested as an important factor for reducing the risk of colon cancer, owing to the abundance of indigestible fiber. Rice bran, which is a component of raw rice after removal of starchy endosperm in milling process, has been shown to be a rich source of some health-beneficial compounds for preventing cancer, hyperlipidaemia, fatty liver, hypercalciuria, kidney stones, and heart disease (Jariwalla, 2001). In the present study, proliferation-inhibitory effects of some rice bran polyphenolic compounds were investigated on a panel of human colorectal cancer (CRC) cell lines, including SW480 (stage B), SW620 (stage C) and Colo-201 (stage D) with increasing metastatic potential according to the Dukes' classification system. / Results from the MTT study revealed that, among the polyphenolic compounds tested, cycloartenyl ferulate (CF) showed the most prominent proliferation inhibition on the CRC cells. CF is one of the typical ferulic acid esters of triterpene alcohols present in rice bran oil. The cancer cell proliferation was reduced by 62, 31 and 21% of their control levels after 72 h of 200 muM CF treatment, respectively. CF seemed to possess higher ability to control proliferation of tumor cells at early stages of cancer development. In meanwhile, results from Toxilight study showed that CF had low toxicity on normal colon CCD-18-Co cells. The anticancer activity of CF was further illustrated by its ability to induce significant regression of SW480 xenograft in nude mice. CF was found to induce apoptosis in SW480 cells in vitro. DNA flow cytometric studies demonstrated that CF elevated dose- and time-dependently the sub G1 or apoptotic cells with fragmented DNA. The pro-apoptotic effect of CF was further confirmed using immunoblotting study showing cleavage of poly(ADP-ribose) polymerase (PARP), which is a hallmark feature of apoptosis. Besides, the executioner procaspase-3, -6 and -7 were found to be processed and activated. On the other hand, administration of pan-caspase inhibitor Z-VAD-FMK completely rescued the cells from PARP cleavage, indicating that CF elicited solely caspase-dependent apoptosis. Elevation of death receptors DR4 and DR5 with the CF treatment seems to originate the upstream activation of the initiator procaspase-8 and -10 of the extrinsic apoptosis pathway. Flow cytometric JC-1 studies further demonstrated that CF significantly altered the mitochondrial membrane potential in a dose-dependent manner together with cytochrome c and smac/DIABLO but not AIF release from mitochondria into the cytosol, as well as the activation of procaspase-9 of the intrinsic apoptosis pathway. Depletion of anti-apoptotic Bcl-2 and elevation of pro-apoptotic Bak were observed; meanwhile, Bid was found to be cleaved by caspase-8, so that the death receptor pathway might be exaggerated by the mitochondrial apoptosis pathway. / Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a promising candidate for cancer therapeutics due to its ability to induce apoptosis selectively in cancer cells (Gura, 1997). Result from MTT study illustrated that SW620 was more resistant than SW480 to TRAIL treatment. It is recognized that SW620 is the metastatic form of SW480 derived from the same patient at a later time, so it is important to develop agents that are able to sensitize the cancer cells to TRAIL, or to recover TRAIL sensitivity. We show for the first time that CF sensitizes SW620 cells to TRAIL-induced apoptosis and the mechanisms involved at least elevation of DR4, enhanced activation of caspase-8 and -3, as well as increase in DNA fragmentation. / Kong, Ka Lai. / Adviser: Wong Yum Shing. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 119-136). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.

Page generated in 0.1326 seconds