In this study the question of nonrandomness in the distribution of human constitutional rearrangements was evaluated. The distribution of breakpoints were analysed in three groups of reciprocal translocations and three groups of inversions, subdivided according to method of ascertainment of cases for study. In addition, one data set of structural aberrations obtained from sperm chromosomes was also analysed. The method of statistical analysis, based on the binomial distribution, was developed specifically to allow testing distributions in chromosome segments as small as chromosome bands. The distribution of breakpoints was analysed in all data sets using this method, in addition to testing for overall nonrandomness using goodness of fit statistics. Nonrandomness in breakpoint distributions was found in reciprocal translocations (rcp) and inversions ascertained through abnormalities and through incidental events. However, random distribution was observed in incidentally ascertained de novo rearrangements as well as in sperm chromosome aberrations. The nonrandomness in the distribution of rcp breakpoints can be largely attributed to a bias in ascertainment of cases based on the phenotypic manifestations of chromosomal imbalance resulting from a rearrangement. A dependence of the probability of producing specific types of balanced or unbalanced progeny on the position of breakpoints is a likely explanation for the nonrandomness produced in breakpoint distributions. However, some bands including, 5q35, 7p22, 9p22, 13ql4, and 17q25, were observed in different ascertainment groups, excluding selection bias as a likely explanation for this observation. These bands may represent true sites of nonrandom rearrangement due to some factor associated with an underlying DNA sequence or structural characteristic of chromatin that predisposes to rearrangement at specific sites. The nonrandomness observed in the distribution of inversion breakpoints is most likely the product of a founder effect. Many identical inversions in apparently unrelated individuals have been found suggesting that a few ancestral mutations have become widespread in the population. A large data set of incidentally ascertained de novo inversions is required to distinguish between sites of frequent breakage and nonrandomness produced by the ascertainment of related cases. All evidence considered together, indisputable predisposition to rearrangement at specific sites was not found in this study. Furthermore, an overall random association of constitutional rearrangement breakpoints in bands with known oncogenes and fragile sites was observed. However, the possibility of oncogenes and fragile sites as factors involved in constitutional rearrangements in a few isolated cases cannot be excluded. Nonrandomness was found when distribution of breakpoints in light and dark G bands was compared. An excess of breakpoints in some light G bands was observed even after a conservative correction for a possible pattern recognition bias which may lead to the overascertainment of breakpoints in light G bands. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

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Li Chung Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 110-123). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.iv / TABLE OF CONTENTS --- p.v / LIST OF FIGURES --- p.ix / LIST OF TABLES --- p.xi / Chapter I. --- INTRODUCTION --- p.1 / Chapter I.1 --- Gastric Carcinoma --- p.1 / Chapter I.2 --- Etiology of Gastric Carcinoma --- p.2 / Chapter I.2.1 --- Environmental Factors: --- p.2 / Chapter I.2.2 --- Helicobacter Pylori Infection: --- p.2 / Chapter I.2.3 --- Genetic Factors: --- p.3 / Chapter I.2.4 --- Other Factors: --- p.4 / Chapter I.3 --- The Lauren Classification of Gastric carcinoma --- p.5 / Chapter I.3.1 --- Histolopathology of Intestinal Type of Gastric Carcinoma --- p.5 / Chapter I.3.2 --- Histopathology of Diffuse Type of Gastric Carcinoma --- p.8 / Chapter I.4 --- Cytogenetics Studies in Gastric Carcinoma --- p.10 / Chapter I.4.1 --- Cytogenetic Studies of Gastric carcinoma --- p.10 / Chapter I.5 --- Molecular Studies of Gastric Carcinoma --- p.14 / Chapter I.5.1 --- Genetic Instability --- p.14 / Chapter I.5.2 --- Amplification/ Mutation of Oncogenes --- p.15 / Chapter I.5.3 --- Alterations of Tumor Suppressor Genes --- p.20 / Chapter I.5.4 --- Cell Adhesion Molecules --- p.23 / Chapter I.5.5 --- Molecular Studies on Intestinal Metaplasia --- p.27 / Chapter II. --- LONG ARM OF CHROMOSOME 6 --- p.28 / Chapter III. --- BRIEF REVIEWS OF THE TECHNIQUES USED IN THIS STUDY --- p.34 / Chapter III.1 --- Comparative Genomic Hybridization (CGH) --- p.34 / Chapter III.2 --- Loss of Heterozygosity (LOH) --- p.37 / Chapter III.3 --- Methylation-Specific PCR (MSP) --- p.38 / Chapter IV. --- OBJECTIVES OF STUDY --- p.40 / Chapter V. --- MATERIALS AND METHODS --- p.41 / Chapter V.l --- Sample Collections --- p.41 / Chapter V.1.1 --- Patients Information for CGH Studies --- p.42 / Chapter V. 1.2 --- Patients Information for LOH Studies --- p.42 / Chapter V.2 --- Extraction of Genomic DNA for Tumor and Normal Tissues --- p.47 / Chapter V.2.1 --- Extraction of Genomic DNA from Frozen Tissues or Paraffin Embedded Sections --- p.47 / Chapter V.2.2 --- Extraction of Genomic DNA from Blood --- p.48 / Chapter V.3 --- Comparative Genomic Hybridization (CGH) of Gastric Carcinoma --- p.49 / Chapter V.3.1 --- Preparation of Normal Metaphase Slides --- p.49 / Chapter V.3.2 --- Metaphase Slide Denaturation --- p.49 / Chapter V.3.3 --- Nick Translation for DNA Labeling --- p.50 / Chapter V.3.4 --- Dot Blot Assay for Biotin and Digoxigenin-Labeled DNA --- p.51 / Chapter V.3.5 --- "Probe Preparation, Denaturation and Hybridization" --- p.51 / Chapter V.3.6 --- Post hybridization Washing and Detection --- p.52 / Chapter V.3.7 --- Image Acquisition and Analysis of CGH Images --- p.53 / Chapter V.4 --- Loss of Heterozygosity (LOH) Analysis on Chromosome 6q --- p.55 / Chapter V.4.1 --- Microsatellite Markers --- p.55 / Chapter V.4.2 --- Polymerase Chain Reaction (PCR) --- p.57 / Chapter V.4.3 --- Denaturing Polyacrylamide Gel Electrophoresis --- p.58 / Chapter V.4.4 --- SYBR Gold Nucleic Acid Gel Staining and Image Viewing --- p.58 / Chapter V.4.5 --- Assessment of Loss of Heterozygosity (LOH) --- p.59 / Chapter V.4.6 --- Statistical Analysis --- p.61 / Chapter V.5 --- Methylation Specific Polymerase Chain Reaction (MSP) --- p.62 / Chapter V.5.1 --- Bisulfite Modification of DNA --- p.62 / Chapter V.5.2 --- Mehtylation Specific PCR --- p.63 / Chapter VI. --- RESULTS --- p.66 / Chapter VI.1 --- Results of CGH --- p.66 / Chapter VI. 1.1 --- Chromosomal Copy Number Aberrations in Gastric Carcinoma --- p.66 / Chapter VI. 1.2 --- Comparison of CGH Results with Intestinal and Diffuse Type of Gastric Carcinoma --- p.67 / Chapter VI.2 --- LOH Analysis of Chromosome 6q --- p.73 / Chapter VII. --- DISCUSSIONS --- p.83 / Chapter VII.l --- Discussions on CGH --- p.83 / Chapter VII.2 --- Discussions on LOH Study --- p.89 / Chapter VII.2.1 --- Two Distinct Deletion Regions --- p.89 / Chapter VII.2.2 --- Possible Candidate Suppressor Genes in Two Deletion Regions --- p.93 / Chapter VII.2.3 --- Infrequent Loss of IGF2R Gene --- p.95 / Chapter VII.3 --- Relationship Between Intestinal Metaplasia and Gastric Carcinoma --- p.99 / Chapter VII.4 --- Microsatellite Instability --- p.100 / Chapter VII.5 --- Correlations --- p.103 / Chapter VII.6 --- Comparison Between CGH and LOH Results on Chromosome 6 --- p.104 / Chapter VII.7 --- Conclusions --- p.106 / Chapter VII.8 --- Limitations of the Study --- p.107 / Chapter VII.8.1 --- Limitation of CGH --- p.107 / Chapter VII.8.2 --- Limited Information Supply by LOH Analysis --- p.107 / Chapter VII.8.3 --- Small Sample Size --- p.107 / Chapter VII.9 --- Future Studies --- p.108 / Chapter VIII. --- REFERENCES --- p.110

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 4 uppsatser.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

Leung Ho-yin. / Thesis submitted in: July 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 104-118). / Abstracts in English and Chinese. / Acknowlegements --- p.i / Abstract (English) --- p.ii / Abstract (Chinese) --- p.iv / "Table of Contents," --- p.vi / List of Figures --- p.xi / List of Tables --- p.xii / Abbreviation --- p.xiii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 . --- Cancer Incidences in Hong Kong --- p.2 / Chapter 1.2. --- Hepatocellular Carcinoma (HCC) --- p.2 / Chapter 1.3. --- "Etiological Risk Factors," --- p.7 / Chapter 1.3.1. --- Liver Cirrhosis / Chapter 1.3.2. --- Chronic Viral Hepatitis / Chapter 1.3.2.1. --- Hepatitis B Virus (HBV) / Chapter 1.3.2.2. --- Hepatitis C Virus (HCV) / Chapter 1.3.3. --- Dietary Aflatoxin B1 exposure / Chapter 1.3.4. --- Heavy Alcohol Consumption / Chapter 1.3.5. --- Hemochromatosis / Chapter 1.4. --- Genetic Aberration in HCC --- p.12 / Chapter 1.4.1. --- Chromosomal Gains / Chapter 1.4.2. --- Chromosome Losses / Chapter 1.5. --- Epigenetic Changes --- p.18 / Chapter 1.6. --- Aims of Thesis --- p.20 / Chapter Chapter 2 --- Materials and Methods --- p.22 / Chapter 2.1. --- Materials --- p.23 / Chapter 2.1.1. --- Culture of Cell Lines / Chapter 2.1.2. --- Preparation of Normal Human Metaphase / Chapter 2.1.3. --- DNA Extraction from Cell Lines / Chapter 2.1.4. --- DNA Extraction from Tissues / Chapter 2.1.5. --- DNA Extraction from Blood / Chapter 2.1.6. --- Nick Translation / Chapter 2.1.7. --- Dot Blot / Chapter 2.1.8. --- Probe Preparation / Chapter 2.1.9. --- Fluorochrome-conjugated antibodies / Chapter 2.1.10. --- Fluorescence Microscopy and Image Analysis / Chapter 2.1.11. --- Primer Labeling / Chapter 2.1.12. --- Polymerase Chain Reaction / Chapter 2.1.13. --- Gel Preparation / Chapter 2.1.14. --- Gel Electrophoresis / Chapter 2.2. --- Sample --- p.28 / Chapter 2.2.1. --- Patients / Chapter 2.2.2. --- Cell Lines / Chapter 2.3. --- Comparative Genomic Hybridization --- p.30 / Chapter 2.3.1. --- Method / Chapter 2.3.1.1. --- Preparation of Normal Human Metaphase / Chapter 2.3.1.2. --- DNA Extraction / Chapter 2.3.1.3. --- Nick Translation / Chapter 2.3.1.4. --- Labeling Efficiency / Chapter 2.3.1.5. --- Probe Preparation / Chapter 2.3.1.6. --- Slide Preparation / Chapter 2.3.1.7. --- Hybridization / Chapter 2.3.1.8. --- Post Hybridization Wash / Chapter 2.3.1.9. --- Image Capturing and Analysis / Chapter 2.3.1.10. --- Control Experiment / Chapter 2.4. --- Microsatellite Analysis --- p.46 / Chapter 2.4.1. --- Method / Chapter 2.4.1.1. --- Fluorescent-Labeled Polymorphic Markers / Chapter 2.4.1.1.1. --- Polymerase Chain Reaction / Chapter 2.4.1.1.2. --- Gel Preparation / Chapter 2.4.1.1.3. --- Gel Electrophoresis / Chapter 2.4.1.1.4. --- Data Analysis / Chapter 2.4.1.2. --- Radioisotope-Labeled Polymorphic Markers / Chapter 2.4.1.2.1. --- Primer Labeling / Chapter 2.4.1.2.2. --- Polymerase Chain Reaction / Chapter 2.4.1.2.3. --- Gel Preparation / Chapter 2.4.1.2.4. --- Gel Electrophoresis / Chapter 2.4.1.2.5. --- Autoradiography and Data Analysis / Chapter 3. --- Chapter 3 Genetic Imbalances on Chromosome 1 --- p.55 / Chapter 3.1. --- Introduction --- p.56 / Chapter 3.2. --- Methods --- p.57 / Chapter 3.2.1. --- Patients and Cell Lines / Chapter 3.2.2. --- CGH / Chapter 3.2.3. --- MSA with Fluorescent-labeled Polymorphic Markers / Chapter 3.2.4. --- Refinement of lp36 loss / Chapter 3.2.5. --- Investigation of Homozygous Deletion in lp36 / Chapter 3.3. --- Results --- p.63 / Chapter 3.3.1. --- CGH / Chapter 3.3.2. --- MSA on Primary HCC Cases / Chapter 3.3.3. --- Refinement of lp36 loss / Chapter 3.3.4. --- Investigation of Homozygous Deletion in lp36 / Chapter 3.3.5. --- CGH vs MSA / Chapter 3.4. --- Discussion --- p.74 / Chapter 4. --- Chapter 4 Genetic Imbalances on Chromosome 4q --- p.78 / Chapter 4.1. --- Introduction --- p.79 / Chapter 4.2. --- Methods --- p.82 / Chapter 4.2.1. --- Patients and Cell Lines / Chapter 4.2.2. --- CGH / Chapter 4.2.3. --- MSA with Radioisotope-labeled Polymorphic Markers / Chapter 4.3. --- Results --- p.86 / Chapter 4.3.1. --- CGH / Chapter 4.3.2. --- MSA / Chapter 4.3.2.1. --- MSA on Primary HCC cases / Chapter 4.3.2.2. --- MSA on In-house developed HCC cell lines / Chapter 4.3.2.3. --- Combined MSA Results / Chapter 4.4. --- Discussion --- p.94 / Chapter 5. --- Chapter 5 Proposed Future Studies --- p.99 / Chapter 5.1. --- "Microarray Analysis," --- p.101 / Chapter 5.2. --- Functional Studies --- p.102 / Chapter 6. --- Bibliography --- p.104

Hui Wai Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 158-189). / Abstracts in English and Chinese. / Abstract / Acknowledgements / List of Tables / List of Figures / Table of Contents / Table of Contents / Chapter Chapter I: --- Introduction --- p.1 / Chapter I. --- Aim of Study --- p.1 / Chapter II. --- Literature Review --- p.3 / Chapter 1. --- Background --- p.3 / Chapter A. --- Epidemiology --- p.3 / Chapter B. --- Histopathology --- p.3 / Chapter C. --- Etiology --- p.4 / Chapter i. --- Environmental Factors --- p.5 / Chapter ii. --- Epstein-Barr Virus (EBV) Infection --- p.6 / Chapter iii. --- Genetic Factors --- p.9 / Chapter 2. --- Molecular Genetics of NPC --- p.11 / Chapter A. --- Genome-Wide Studies --- p.11 / Chapter i. --- Comparative Genomic Hybridization (CGH) --- p.11 / Chapter ii. --- Loss of Heterozygosity (LOH) Studies --- p.12 / Chapter iii. --- Homozygous Deletion Study --- p.12 / Chapter B. --- NPC-related Oncogenes and Tumor Suppressor Genes --- p.13 / Chapter i. --- Oncogenes --- p.13 / Chapter ii. --- Tumor Suppressor Genes --- p.14 / Chapter 3. --- Chromosome 14q and NPC --- p.19 / Chapter A. --- Tumor Suppressor Loci and Cancer-Related Genes on Chromosome14q --- p.20 / Chapter i. --- Tumor Suppressor Loci on Chromosome 14q --- p.20 / Chapter ii. --- Cancer-Related Genes on Chromosome 14q --- p.26 / Chapter 4. --- Chromosome 16q and NPC --- p.28 / Chapter A. --- Tumor Suppressor Loci and Candidate Tumor Suppressor genes on Chromosome16q --- p.28 / Chapter i. --- Tumor Suppressor Loci on Chromosome 16q --- p.28 / Chapter ii. --- Metastasis Suppressor Loci on Chromosome 16q --- p.34 / Chapter iii. --- Candidate Tumor Suppressor Genes on Chromosome 16q --- p.34 / Chapter Chapter II: --- Materials and Methods --- p.40 / Chapter I. --- Cell Lines and Xenografts --- p.40 / Chapter 1. --- Cell Lines --- p.40 / Chapter 2. --- Xenografts --- p.41 / Chapter 3. --- DNA Extraction --- p.42 / Chapter II. --- Patients and Biopsy Specimens --- p.44 / Chapter 1. --- Manual Microdissection --- p.44 / Chapter 2. --- Laser Captured Microdissection (LCM) --- p.46 / Chapter 3. --- DNA Extraction --- p.46 / Chapter III. --- Comprehensive Screening for Homozygous Deletion Regions on Chromosomes 14q32.12-32.33 and 16q23.1-24.3 in Human Cancers --- p.48 / Chapter 1. --- DNA of Human Cancer Cell Lines --- p.48 / Chapter 2. --- Sequence-Tagged Sites (STS) Markers --- p.48 / Chapter 3. --- Polymerase Chain Reaction (PCR) --- p.49 / Chapter IV --- . Investigation of Inactivation of Potential Tumor Suppressor Genes on Chromosome 14q32.12-32.33 and 16q23.1-24.3 --- p.58 / Chapter 1. --- Detection of Homozygous Deletion --- p.58 / Chapter 2. --- Expression Analysis --- p.58 / Chapter A. --- RNA Extraction --- p.58 / Chapter B. --- Reverse-Transcription (RT) PCR --- p.61 / Chapter i. --- DNase I Digestion --- p.62 / Chapter ii. --- First-strand cDNA Synthesis and RNase Digestion --- p.62 / Chapter iii. --- Reverse-Transcription (RT)-PCR --- p.63 / Chapter C. --- Real-Time RT PCR --- p.63 / Chapter 3. --- Methylation Analysis --- p.68 / Chapter A. --- Sodium Bisulfite Modification --- p.68 / Chapter B. --- Methylation-Specific PCR (MSP) --- p.69 / Chapter C. --- Bisulfite Sequencing --- p.70 / Chapter D. --- Combined Bisulfite Restriction Analysis (COBRA) --- p.75 / Chapter E. --- 5 -aza-2' -deoxycytidine Treatment --- p.76 / Chapter ChapterIII： --- Results --- p.78 / Chapter I. --- Comprehensive Screening for Homozygous Deletion Regions in Human Cancers --- p.78 / Chapter 1. --- Chromosome 14q32.12-3233 --- p.78 / Chapter 2. --- Chromosome 16q23.1-243 --- p.79 / Chapter II. --- Investigation of Inactivation of Potential Tumor Suppressor Genes in NPC --- p.86 / Chapter 1. --- Chromosome 14q --- p.86 / Chapter A. --- "WW Domain-Containing Protein, 45-kD （WW45)" --- p.86 / Chapter B. --- Apoptosis Stimulating Protein of p53（ASPP1) --- p.88 / Chapter 2. --- Chromosome 16q --- p.92 / Chapter A. --- WW Domain-Containing Oxidoreductase （WWOX) --- p.92 / Chapter i. --- Homozygous Deletion Screening of WWOX --- p.92 / Chapter ii. --- Expression of Aberrant Splicing Transcripts of WWOX in NPC --- p.94 / Chapter iii. --- Sequencing of WWOX Aberrant Transcripts --- p.95 / Chapter iv. --- Quantitative Analysis of WWOX Transcripts in NPC --- p.95 / Chapter v. --- Methylation Analysis --- p.99 / Chapter B. --- H-Cadherin (CDH13) --- p.102 / Chapter i. --- Analysis of H-cadherin Deletion on Cancer Cell Lines and Xenografts --- p.102 / Chapter ii. --- Expression Analysis of H-Cadherin by RT-PCR and Real-Time RT-PCR --- p.102 / Chapter iii. --- Analysis of Promoter Hypermethylation by Methylation-Specific PCR (MSP) and Bisulfite Sequencing in NPC Cell Lines and Xenografts --- p.104 / Chapter iv. --- Demethylation Study of H-Cadherin in C666-1 Cell Line --- p.105 / Chapter v. --- Methylation Analysis of H-Cadherin in Primary Tumors --- p.105 / Chapter vi. --- Methylation Analysis of H-Cadherin in Human Cancer Cell Lines --- p.106 / Chapter C. --- Myeloid Translocation Gene on Chromosome 16 (MTG16) --- p.113 / Chapter i. --- Deletion Analysis of MTG16 in Cancer Cell Lines and Xenografts --- p.113 / Chapter ii. --- Differential Expression of MTG16a and MTG16b Transcripts in NPC Cell Lines and Xenografts --- p.113 / Chapter iii. --- Methylation Analysis of MTG16b in NPC Cell Lines and Xenografts --- p.118 / Chapter iv. --- Sequencing of MTGl 6b RT-PCR Products --- p.119 / Chapter v. --- Demethylation Study of MTG16b in HK-1 Cell Line --- p.119 / Chapter vi. --- Promoter Methylation Analysis of MTG16b by MSP in Primary NPC and Cancer Cell Lines --- p.120 / Chapter Chapter IV: --- Discussion --- p.124 / Chapter I. --- Comprehensive Homozygous Deletion Screening of Chromosomes 14q32.12-32.33 and 16q23.1-24.3 in Human Cancer Cell Lines and Xenografts --- p.124 / Chapter II. --- Investigation of Candidate Tumor Suppressor Genes on Chromosome 14q in NPC --- p.128 / Chapter III. --- Alterations of Candidate Tumor Suppressor Genes on Chromosome 16q in NPC --- p.133 / Chapter 1. --- Expression of Aberrant Transcripts of WWOX in NPC --- p.133 / Chapter 2. --- Methylation-Associated Silencing of H-Cadherin and MTG16b in NPC --- p.140 / Chapter Chapter V: --- Conclusion --- p.154 / Chapter Chapter VI: --- References --- p.158

Abstract Studies on families and individuals with sex chromosome abnormalities and 46,XY females, together with molecular research, have provided proof that both X and Y chromosome genes are expressed in human tooth crown growth. The Y chromosome promotes the formation of both permanent tooth crown enamel and dentin, whereas the effect of the X chromosome is seen mainly in enamel formation. In particular, the effect of the Y chromosome on dentin formation explains the expression of sexual dimorphism in crown size. When crown growth is complete, root dentin is formed and requires proliferation of epithelial cells in Hertwig's epithelial root sheath to initiate the differentiation of root odontoblasts. These epithelial cells determine the size, shape and number of the roots. There is a clear sex difference in tooth crown sizes, men have larger teeth than women. The aim of this research was to study completed permanent tooth root lengths in individuals with sex chromosome abnormalities and 46,XY females, an approach which might also provide some clues for a further insight into the development of sexual dimorphism in human growth. The underlying hypothesis was that the effect of the X and Y chromosomes on crown growth is also expressed in root growth. The subjects were participants of L. Alvesalo's research project, Kvantti, and comprised 45,X/46,XX females, 47,XYY and 47,XXY males and female sex reversals with insensitivity to androgens (46,XY females). The root lengths were measured from dental panoramic radiographs with a sliding digital calliper. All available teeth (except third molars) with complete root formation on both sides of the jaws were measured. The results showed longer final permanent tooth root lengths in 47,XYY and 47,XXY males, while the roots in 45,X/46,XX females were shorter compared with the values of normal men and women, respectively. The root lengths of 46,XY females were longer compared to normal women and placed on a level with normal men. The root morphology did not reveal any major deviations from normal variation. In terms of population dental developmental standards it is conceivable that changes in these study groups in final size of their permanent tooth roots become evident during a period beginning eight years after birth and continuing up to the age of 14 years, at least. It became clear that the effect of the Y chromosome on tooth root growth is greater than that of the X chromosome, and this may cause the observed sexual dimorphism, males having longer roots than females. It is suggested that root growth may be affected by the same genes on the X and Y chromosomes which promote crown growth.

Chan Ching Yin. / Thesis submitted in: October 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 197-221). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.iii / Abstract in Chinese --- p.vi / List of abbreviations --- p.ix / List of tables --- p.xv / List of figures --- p.xvi / Contents --- p.xviii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- What are astrocytic tumors? --- p.1 / Chapter 1.1.1. --- Histological characteristics and classification --- p.2 / Chapter 1.1.2. --- Epidemiology --- p.2 / Chapter 1.1.3. --- Treatment and patient survival --- p.4 / Chapter 1.2. --- "Cytogenetics, molecular genetics and epigenetics of astrocytic tumors" --- p.6 / Chapter 1.2.1. --- Cytogenetics --- p.6 / Chapter 1.2.2. --- Genetic imbalances --- p.7 / Chapter 1.2.3. --- Tumor suppressor genes --- p.13 / Chapter 1.2.4. --- Oncogenes --- p.22 / Chapter 1.2.5. --- Primary and secondary GBMs --- p.26 / Chapter 1.3. --- Major pathways involved in astrocytic tumorigenesis --- p.30 / Chapter 1.3.1. --- Cell cycle dysregulation and suppression of apoptosis --- p.30 / Chapter 1.3.2. --- Promotion of proliferation and survival --- p.33 / Chapter 1.4. --- BRAF mutation in human cancers --- p.38 / Chapter 1.5. --- Other CNS tumors included in the current study --- p.52 / Chapter 2. --- Aims of study --- p.61 / Chapter 3. --- Materials and methods --- p.64 / Chapter 3.1. --- Clinical materials --- p.64 / Chapter 3.2. --- Cell lines --- p.75 / Chapter 3.3. --- Cell culture --- p.77 / Chapter 3.4. --- DNA extraction --- p.78 / Chapter 3.4.1. --- Pre-treatment of samples --- p.78 / Chapter 3.4.2. --- Cell lysis and protein removal --- p.80 / Chapter 3.4.3. --- Precipitation of DNA --- p.81 / Chapter 3.4.4. --- Determination of DNA concentration --- p.81 / Chapter 3.5. --- Mutation analysis of BRAF by cycle sequencing --- p.83 / Chapter 3.5.1. --- Amplification of BRAF exons --- p.83 / Chapter 3.5.2. --- Cycle sequencing and automated gel electrophoresis --- p.84 / Chapter 3.6. --- Immunohistochemistry of B-Raf and GFAP --- p.87 / Chapter 3.6.1. --- Pre-treatment of samples --- p.87 / Chapter 3.6.2. --- Detection of B-Raf and GFAP antigens by ABC method --- p.88 / Chapter 3.6.3. --- Controls --- p.90 / Chapter 3.7. --- Quantification of EGFR gene dosage by TaqMan based real-time PCR --- p.91 / Chapter 3.7.1. --- Preparation of gene constructs --- p.92 / Chapter 3.7.2. --- Primers and TaqMan probes --- p.93 / Chapter 3.7.3. --- Experimental condition and PCR program --- p.95 / Chapter 3.7.4. --- DNA standards --- p.95 / Chapter 3.7.5. --- Controls --- p.96 / Chapter 3.7.6. --- Experimental layout --- p.96 / Chapter 3.8. --- Microsatellite analysis of chromosome 14q in astrocytic tumors --- p.97 / Chapter 4. --- Results --- p.101 / Chapter 4.1. --- Mutation analysis of BRAF --- p.101 / Chapter 4.2. --- Immunohistochemistry of B-Raf protein --- p.107 / Chapter 4.3. --- Quantification of EGFR gene dosage --- p.117 / Chapter 4.4. --- Correlation between EGFR dosage and BRAF mutation --- p.128 / Chapter 4.5. --- Correlation between EGFR dosage and B-Raf expression --- p.129 / Chapter 4.6. --- Microsatellite analysis of chromosome 14q in astrocytic tumors --- p.131 / Chapter 5. --- Discussions --- p.149 / Chapter 5.1. --- BRAF mutations as common events in human cancers --- p.149 / Chapter 5.2. --- BRAF mutation in CNS tumor specimens --- p.150 / Chapter 5.2.1. --- Tumorigenic effect of the V599E substitution --- p.153 / Chapter 5.2.2. --- V599E B-Raf mutant activation independent of Ras activation --- p.155 / Chapter 5.2.3. --- Autocrine stimulation of Ras signaling in V599E B-Raf mutant --- p.156 / Chapter 5.3. --- BRAF expression in astrocytic tumors --- p.159 / Chapter 5.4. --- Mutually exclusive pattern between EGFR amplification and BRAF expression --- p.161 / Chapter 5.4.1. --- Similar effect of EGFR activation and B-Raf activation --- p.163 / Chapter 5.4.2. --- Mutual effects between Ras/Raf/Mek/Erk and Akt signaling --- p.164 / Chapter 5.5. --- Microsatellite analysis of chromosome 14q in human cancers --- p.167 / Chapter 5.6. --- Microsatellite analysis of chromosome 14q in astrocytic tumors --- p.170 / Chapter 5.6.1. --- Finer mapping of common regions of deletion --- p.170 / Chapter 5.6.2. --- Genes within the common regions of deletion --- p.173 / Chapter 5.6.3. --- Overlapping deletion regions in astrocytic and non-CNS tumors --- p.186 / Chapter 6. --- Further studies --- p.190 / Chapter 6.1. --- Role of BRAF alterations in astrocytic tumors --- p.190 / Chapter 6.2. --- B-Raf expression in astrocytic tumors and correlation with EGFR overexpression --- p.193 / Chapter 6.3. --- Microsatellite analysis of 14q in astrocytic tumors --- p.194 / Chapter 7. --- Conclusions --- p.195 / Chapter 8. --- References --- p.198