Thesis (M.Med.Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 63-68).

Thesis (M.Sc.)--University of Adelaide, Dept. of Anatomical Sciences, 2005? / Title from title page of source document; viewed July 19 2005. Bibliography: p. 91-107 of source document. Also available in print and CD-ROM forms.

Thesis (M.A.)--Central Connecticut State University, 2004. / Thesis advisor: Kathy Martin-Troy. " ... in partial fulfillment of the requirements for the degree of Master of Arts in Biology." Includes bibliographical references (leaves 21-23). Also available via the World Wide Web.

Functional inactivation of tumor susceptibility gene tsg101 leads to cellular transformation and tumorigenesis in mice. No genomic DNA deletion in TSG101gene in human cancer indicated TSG101 is not a typical tumor suppressive gene. TSG101 participates in the MDM2/p53 feedback control loop and the regulation of the cellular membrane trafficking. However, detail functional characteristics remains to be elucidate. In this study, we explored the tsg101 expression in adult mouse tissues from various organs using immunohistochemistry and in situ hybrid- ization. The results indicated that tsg101 expression was ubiquitous but in differential steady-state level in various cell types. The expression of tsg101 mainly found in epithelial cells¡Bsecretory cells and nerve cells. The second topic of this study was to characterize the phosphorylation status of TSG101 protein. Endogeneously expressed TSG101 and exogeneously expressed HA-tag TSG101 protein were purified by immunoprecipiation with #820 antiserum against TSG101, and were subjected for western blot analysis using anti-phosphoserine and anti-phosphothreonine antibodies. This experiment had confirmed that TSG101 protein contained both phosphoserine and phosphthreonine residues. In vitro kianse assay using GST-tag and his-tag TSG101 funsion proteins was exploited to investigate the kinase responsible for TSG101 phosphorylation. The results clearly indicated that cdc2¡BGSK3£] and PKC kinases could phosphorylate TSG101 fusion Protein, implying that the function of TSG101 might be regulated by the signaling involving these kinases.

Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997. / Errata inserted. Bibliography: leaves 98-120.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains iv, 27 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 26-27).

Thesis (MSc)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The cellular expression of the enzymes implicated in regulating sucrose metabolism and accumulation in sugarcane is poorly understood. The present study was therefore aimed at the development of an in situ hybridisation (ISH) technique to study differential gene expression among the various cell types of the sugarcane culm. This technique in conjunction with northern and western blotting was then used to determine the sites of cellular and tissue specific expression of the cytosolic enzymes, UDP-Glc dehydrogenase, pyrophosphate dependent phosphofructokinase and UDP-Glc pyrophosphorylase, involved in sucrose metabolism. This study revealed that the determination of the influencing parameters associated with the development of an ISH protocol was essential for the successful detection of the endogenous RNA sequences in sugarcane internodal tissues. The parameters that were investigated included the type of embedding medium, duration of fixation period, pre-treatment procedures and hybridisation temperature. It further revealed that fresh internodal tissue sections, fixed for a period of 24 h and thereafter exposed to pre-treatment and hybridisation, facilitated the analysis of cytological gene expression at all stages of sugarcane development. The second part of this study revealed very localised transcript expression for UDP-Glc DH, PFP and UGPase in the different internodal tissue and cell types. The UDP-Glc DH and UGPase transcripts were localised to the phloem elements, whilst xylem tissue only expressed the UDP-Glc DH transcript. Transcripts of UDP-Glc DH, PFP and UGPase were all expressed in the parenchyma cells that were associated with the vascular bundles and the stem storage compartment, suggesting that the parenchyma cells distributed throughout the stem in the different tissue types complement each other in function for the purposes of phloem loading, unloading and assimilate transport processes. Complimentary northern and western hybridisations demonstrated that internode 7 represents a shift in the sink from utilisation to storage. This is evident by the observed decline in both the relative transcript and protein abundances of UDP-Glc DH, PFP and UGPase at this stage of development. The relative mRNA and protein abundances for the three enzymes showed a similar trend. Higher levels of the gene transcripts and translated products were observed in the younger sucrose importing tissues, than in the older sucrose accumulating internodes. At a cellular level, it was found that the sites of cellular UDP-Glc DH, PFP and UGPase expression differed marginally. Whilst UDP-Glc DH was expressed in the phloem, xylem and parenchyma cells of the vascular complex and in storage parenchyma cells, PFP was expressed exclusively in parenchyma cells that were associated with the vascular bundles and those serving a storage function in the stem pith and UGPase was found to be localised in the phloem and parenchyma of the vascular bundles and the storage parenchyma cells. Such findings have demonstrated an increase in resolution with which gene expression can be examined at a cellular level. Hence, the results from this study have demonstrated that the knowledge of metabolic compartmentation between different tissue and cell types is a requisite to understanding the function(s) of individual enzymes within complex structures such as the sugarcane culm. / AFRIKAANSE OPSOMMING: Die sellulêre lokalisering van die ensieme wat geïmpliseer word in die regulering van sukrose metabolisme is onbekend. Met dit in gedagte, was hierdie studie gefokus op die ontwikkeling van 'n in situ hibridisasie (ISH) tegniek om differensiële geenuitdrukking in die verskillende seltipes van die suikerrietstingel te ondersoek. Hierdie tegniek, tesame met RNA-en proteïen gel blots, is volgens aangewend om die areas van sellulêre-en weefselspesifieke uitdrukking van die sitosoliese ensieme UDP-glukose dehydrogenase, pirofosfaat-afhanklike fosfofruktokinase en UDP-glukose pirofosforilase, wat almal betrokke is by sukrosemetabolisme, te bepaal. Dit het duidelik geword gedurende die studie dat die bepaling van die optimale parameters van die ISH protokol vir suikerriet van deurslaggewende belang sou wees vir die opsporing van endogene RNA volgordes. Die parameters wat ondersoek is het ingesluit die tipe inbeddingsmedium, die tydsduur van fiksering, vooratbehandelings- en hibridisasiemetodes. Dit het duidelik geword dat vars internodale weefselsnitte wat vir 24 h gefikseer is en daarna voorafbehandeling en hibridisasie ondergaan het, die bepaling van geenuitdrukking tydens alle fases van suikkerrietontwikkeling moontlik gemaak het. Die tweede fase van hierdie studie het aangetoon dat al drie ensieme spesifiek gelokaliseerde uitdrukkingspatrone gehad het in verskillende internodale weefsels en seltipes. Al drie gene is konstitutief uitgedruk in internodes. Die UDP-glukose dehydrogenase en UDP-glukose pirofosforilase transkripte is gelokaliseer na die floeëm elemente, terwyl xileem slegs die UDP-glukose dehydrogenase transkripte bevat het. Al die gene is in die parenchiemselle uitgedruk wat geassosieer is met die vaatbondels en die stingel stoorkompartement, wat moontlik beteken dat die parenchiem selle wat deur die stingel versprei is 'n sentrale netwerk vorm wat direk of indirek koolstofassimileringsprosesse beïnvloed. RNA-en proteïen gel blots op dieselfde internodes het gewys dat internode sewe 'n verskuiwing, van koolstofverbruik na berging, verteenwoordig. Dit word gerllustreer deur die afname in beide transkrip en proteïen vlakke van die drie ensiem in hierdie stadium van ontwikkeling. Alhoewel beide mRNA en proteïen vlakke vir al die ensieme 'n soortgelyke tendens getoon het, het die sellulêre uitdrukking van die ensieme volgens ISH verskil, wat die krag van die tegniek illustreer. Die resultate van hierdie studie het gedemonstreer dat begrip van die kompartementalisasie van metabolisme tussen verskillende weefsel-en seltipes 'n voorvereiste is om die funksie/s van individuele ensieme in komplekse strukture soos die suikerrietstingel te bepaal.

published_or_final_version / Pathology / Master / Master of Medical Sciences

Multicolor fluorescence in-situ hybridization (M-FISH) techniques provide color karyotyping that allows simultaneous analysis of numerical and structural abnormalities of whole human chromosomes. Chromosomes are stained combinatorially in M-FISH. By analyzing the intensity combinations of each pixel, all chromosome pixels in an image are classified. Often, the intensity distributions between different images are found to be considerably different and the difference becomes the source of misclassifications of the pixels. Improved pixel classification accuracy is the most important task to ensure the success of the M-FISH technique. Along with a reliable pixel classification method, automation of the karyotyping process is another important goal. The automation requires segmentation of chromosomes, which not only involves object/background separation but also involves separating touching and overlapping chromosomes. While automating the segmentation of partially occluded chromosomes is an extremely challenging problem, a pixel classification method that satisfies both high accuracy and minimum human intervention has not been realized. The main contributions of this dissertation include development of a new feature normalization method for M-FISH images that reduces the difference in the feature distributions among different images, and development of a new decomposition method for clusters of overlapping and touching chromosomes. A significant improvement was achieved in pixel classification accuracy after the new feature normalization. The overall pixel classification accuracy improved by 40% after normalization. Given a cluster, a number of hypotheses was formed utilizing the geometry of a cluster, pixel classification results, and chromosome sizes, and a hypotheis that maximized the likelihood function was chosen as the correct decomposition. Superior decomposition results were obtained using the new method compared to the previous methods. Contributions also include development of a color compensation method for combinatorially stained FISH images (including M-FISH images) based on a new signal model for multicolor/multichannel FISH images. The true signal was recovered based on the signal model after color compensation. The resulting true signal does not have color spreading (channel crosstalk) among different color channels. Two new unsupervised nonparametric classification methods for M-FISH images are also introduced in this dissertation: a fuzzy logic classifier and a template matching method (a minimum distance classifier). While both methods produce an equivalent accuracy compared to a supervised classification method, their computation time is significantly less than a Bayes classifier. Highly sophisticated and practical algorithms have been developed through this research. Using the developed methods, the amount of human intervention required will be significantly reduced: chromosomes are reliably and accurately segmented from the background, pixels are accurately classified, and clusters of overlapping and touching chromosomes are automatically decomposed. / text