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  • 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.
201

Proteomic studies on development factors of pig embryonic stem cells into neural cells by RA in vitro

Chen, Chin-tan 04 August 2005 (has links)
Proteomic techniques were used to analyze the protein expression profile of the early-stage differentiation of pig embryonic stem cells (ES cells). The pig ES cells were induced to develop to neuronal cells by all-trans retinoic acid (ATRA) in vitro by Tainan Livestock Research Institute. The ES cells were cultured with ATRA and collected at time intervals of 0, 1, 2, 4, 8 and 10 days. The cell lysates were analyzed by two-dimensional electrophoresis, and the differentially expressed proteins are identified by MALDI-TOF. Our data shows that the expression profile of pig ES cells is similar to other mammalian models but with some differences. Preliminary pig ES cells 2D database was set up. Six spots each with up or down-regulation in neurogenesis were identified by MS. These proteins may become the good markers of pig ES cells into neural cells by RA. Among those proteins, vimentin, prohibitin and annexin A10 were up-regulated, zinc finger protein 482 (ZNF482), fyn-related kinase (FRK) and annexin A1 were down-regulated during differentiation of pig ES cells to neural cells. Addtionally, we ultilized RT-PCR technique to investigate mRNA expression during neurogenesis, vimentin and prohibitin was up-regulated, anxa1(annexin A1) was slightly down-regulated, neuroD1 and neurogenin 2 were high expression on day 10, beta-catenin was high expression on day 8 to 10.
202

Studies On Novel Immunogenic Proteins Of Clostridium Chauvoei

Coral, Didem 01 December 2009 (has links) (PDF)
Clostridium chauvoei is a gram-positive, spore-forming anaerobic bacterium. It is the pathogenic agent of blackleg, a disease causing serious toxemia and high mortality in cattle, sheep and many other domestic and wild animals. It is considered the most important Clostridium producing economic losses in livestock. Typically, animals infected with blackleg die rapidly without any signs of illness. Animals quickly die within 12 to 48 hours after contracting the disease. Therefore, the control of this disease is done by commercial vaccines consisting of whole formolized cultures. Immunity against C. chauvoei is associated with whole cell, including its somatic and flagellar antigens while in other clostridial diseases, protective immunity is obtained by the use of vaccines containing toxoids. Moreover, it is essential to obtain new information about the somatic antigens of C. chauvoei. Proteomics is the study of the proteome, the protein complement of the genome. The proteome has been defined as the entire complement of proteins expressed by a cell, organism, or tissue type, and accordingly, proteomics is the study of this complement expressed at a given time or under certain environmental conditions. 2-DE with Immobilized pH Gradients (IPGs) combined with protein identification by Mass Spectrometry (MS) is currently the workhorse for proteomics. Much of information about immunogenic component can be derived from proteomics coupled to Western blotting, namely immunoproteomics. Our study constitutes the first immunoproteomic analysis of C. chauvoei to identify candidate immunogenic antigens for development of new vaccines. Analyses were performed by Western blot and dot blot techniques against the whole cell extract proteins of C. chauvoei separated by 2-DE. Firstly, the growth conditions of two different strains, C. chauvoei ATCC 11957 and C. chauvoei 20 were optimized. After mice immunization studies with experimental vaccines prepared, sera were obtained for evaluation of the immunoglobulin G antibody level by ELISA. After high level of antibody response determination, 1-DE, 2-DE and immunoblot studies were performed for the characterization of immunogenic proteins. In the study, a total of 460 protein spots could be detected on the 2-DE gels by the help of Delta2D image analysis software and 30 of them were reacted with polyclonal antibodies against inactivated whole cells of C. chauvoei. Among these 30 spots, and 8 of them could be characterized by MALDI-TOF MS analyses. Of these 8 spots revealed four different gene products (distinct ORFs). Ornithine decarboxylase, methionine adenosyltransferase, glucose-6-phosphate isomerase, and flagellin protein FliB (C) are the characterized proteins. Glucose-6-phosphate isomerase has been identified as an immunogenic protein for a pathogenic microbe and in C. chauvoei for the first time. Methionine adenosyltransferase and ornithine decarboxylation were identified as immunogenic for C. chauvoei for the first time. The last defined protein is the flagellin protein FliB(C) which is known to be major immunogenic protein of C. chauvoei.
203

Assessing the diversity of agrobacterial populations

Shams, Malek 19 December 2012 (has links) (PDF)
Agrobacterium are Alphaproteobacteria common in most soils that closely interact with plants in two respects. Firstly, they are rhizospheric bacteria saprophytically living in the rhizosphere of numerous plants and they are likely beneficial to plants. Secondly, when they harbor a dispensable Ti plasmid (i.e. tumor inducing plasmid), agrobacteria are plant pathogens able to cause the crown gall disease to most dicots and gymnosperms and some monocots. An epidemiological survey of crown gall thus also requires expert determination of the Agrobacterium taxonomy. In this thesis we evaluated the usefulness of MALDI-TOF MS technique as a high throughput tool to determine and classify agrobacteria. Then we set up a recA-based PCR method to accurately and exhaustively assess agrobacterial diversity either of isolated agrobacteria or directly in various biotopes. We applied standard biochemical, recA-based and Ti plasmid-based identification methods to study the prevalence of pathogenic and non-pathogenic agrobacteria at the country and local scales. Finally, we tested whether analyzing the internal composition of recA amplicons could be a way to directly assess the micro-diversity of agrobacterial populations using cloning sequencing or pyrosequencing approaches. The later methodology was applied to establish the actual field diversity of Agrobacterium and to evaluate whether plant genotypes differentially select agrobacteria in their root systems, providing first data upon biotic factors shaping the population structure of agrobacteria
204

Genetic elements and molecular mechanisms driving the evolution of the pathogenic marine bacterium Vibrio parahaemolyticus

Hazen, Tracy Heather 06 July 2009 (has links)
Vibrio parahaemolyticus is an opportunistic human pathogen that occurs naturally in a non-pathogenic form in coastal estuarine and marine environments worldwide. Following the acquisition of virulence-associated genes, V. parahaemolyticus has emerged as a significant pathogen causing seafood-borne illnesses. The mechanisms and conditions that promote the emergence of disease causing V. parahaemolyticus strains are not well understood. In addition, V. parahaemolyticus clinical strains isolated from disease-associated samples and environmental strains from sediment, water, and marine organisms have been identified with considerable diversity; however, the evolutionary relationships of disease-causing strains and environmental strains are not known. In the following research, the evolutionary relationships of V. parahaemolyticus clinical and environmental strains are examined. In addition, the contribution of genetic elements and molecular mechanisms such as deficiency of DNA repair to the evolution of V. parahaemolyticus clinical and environmental strains is shown. Molecular analysis of the evolutionary relationships of V. parahaemolyticus clinical and environmental strains demonstrated separate lineages of pathogenic and non-pathogenic strains with the exception of several environmental strains that may represent a reservoir of disease-causing strains in the environment. Sequence characterization of plasmids isolated from diverse environmental Vibrios indicated a role of plasmids in strain evolution by horizontal transfer of housekeeping genes. In addition, analysis of plasmids from V. parahaemolyticus clinical and environmental strains indicated the existence of a plasmid family distributed among V. parahaemolyticus, V. campbellii, and V. harveyi environmental strains. Sequence characterization of a plasmid of this family from a V. parahaemolyticus environmental strain indicated the contribution of these plasmids to the emergence of the clonal pandemic strains. Investigation of the role of molecular mechanisms to the evolution of V. parahaemolyticus strains showed that inactivation of the DNA repair pathway methyl-directed mismatch repair (MMR) increased the accumulation of spontaneous mutations leading to increased nucleotide diversity in select genes. The research findings in the following chapters demonstrate a considerable contribution of genetic elements and molecular mechanisms to the evolution of genetic and phenotypic diversity.
205

Elucidating the role of silicone in the treatment of burn scars : an essential step in the development of improved treatment products

Sanchez, Washington H. January 2006 (has links)
Hypertrophic scarring is a common occurrence for severe burn victims leading to major functional, physiological, and aesthetic effects to the patients. Limiting the hypertrophic scarring of the patients alleviates the functional, physiological, and aesthetic effects. Silicone gels, over the past decade, have been widely used to remediate and limit hypertrophic scarring but the mechanism of action is yet to be determined. One explanation has been that hydration of the outermost area of the burn is induced by the silicone gel . However, non-silicone polymers which increase hydration could not mimic the effect. An alternative interpretation is that there may be silicone species that migrate from the silicone gel into the viable tissue to mediate reactions in the extra-cellular matrix that result in a decreased deposition of excessive amounts of collagen - a central feature of the hypertrophic scar. A novel and informative technique to study these species is MALDI-TOF/MS (Matrix Assisted Laser Desorption Ionisation-Time of Flight Mass Spectrometry) in conjunction with gel permeation chromatography. MALDI-TOF/MS, which has allowed the detection of intact molecular species that were not possible with more established mass spectrometric techniques. The mobile species that may migrate from polydimethylsiloxane medical gel sheeting into skin have been identified by MALDI-MS. The bulk gel contains predominantly cyclic oligomers with a mass distribution peaking at n = 19 (number of repeating siloxane units), but in an aqueous environment the species at the surface of the silicone medical gel are predominantly methyl/methylol-terminated linear siloxanes. By using a gelatine matrix as a model substrate, the distribution of silicon after application of the silicone gel for 16 weeks was determined by Energy-dispersive X-Ray mapping of the sectioned gelatine. The association of the linear and cyclic oligomers with proteins relevant in hypertrophic scarring are considered. The mobility of silicone species across stratum corneum was confirmed by Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FT/IR). This method confirms our hypothesis that not only are the low molecular weight silicone species mobile, but also that they do traverse the natural barrier, the stratum corneum, to levels that are detectable by ATR after a continuous application over approximately 11 days. Invitro studies of the effects of LMWS on primary line fibroblast cells indicate a response that down regulates the proliferation of fibroblast cells and protein production. Preliminary results indicate that a family of pendant functional LMWS are effective in down regulating hypertrophic-derived fibroblast primary cells. Studies on hypertrophic scar tissue treated with silicone medical gel indicate that LMWS permeate across the stratum corneum into viable scar tissue. In some areas, the LMWS tend to pool as detected by SEM/EDX elemental silicon analysis. These areas of LMWS pooling tend to be composed of highly disorganised collagen nodules.
206

Development of a MALDI-TOF-MS Method for the Analysis of Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA) in Search of BMAA Incorporation in Biological Samples

Conklin, Laura M 10 November 2015 (has links)
Beta-N-methylamino-L-alanine (BMAA) is a non-protein amino acid produced by many cyanobacteria, and thought to induce neurotoxic effects through excitotoxicity, contributing to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis/Parkinsonism-dementia complex (ALS-PDC) and Alzheimer’s. The ubiquitous nature of cyanobacteria, and evidence of biomagnification through our food web, creates a dire need for the development of an analytical platform that will provide accurate identification and quantification of BMAA amounts in our ecosystem and potential food supply. The present study evaluated the ability of a MALDI-ToF-MS method to detect and quantify BMAA in a variety of biological matrices. Through validation procedures, it was demonstrated that this MALDI-ToF-MS method provided comparable data to currently accepted analytical methods, specifically LC-MS/MS. Further, the development of said method reduced sample preparation and data acquisition time (1-2 seconds per sample), while providing high throughput analysis and eliminating the need for derivatization, chromatographic separation, and modification of amino acids.
207

Elevated levels of circulating ITIH4 are associated with hepatocellular carcinoma with nonalcoholic fatty liver disease: From pig model to human study / 血清ITIH4の上昇は非アルコール性脂肪性肝疾患からの肝細胞癌発症と関連する:ブタからヒトへ

Nakamura, Naohiko 23 January 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22148号 / 医博第4539号 / 新制||医||1039(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 坂井 義治, 教授 小西 靖彦, 教授 滝田 順子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
208

Genomic and proteomic analysis of drought tolerance in Sorghum (Sorghum bicolor (L.) Moench)

Woldesemayat, Adunga,Abdi January 2014 (has links)
Philosophiae Doctor - PhD / Drought is the most complex phenomenon that remained to be a potential and historic challenge to human welfare. It affects plant productivity by eliciting perturbations related to a pathway that controls a normal, functionally intact biological process of the plant. Sorghum (Sorghum bicolor (L.) Moench), a drought adapted model cereal grass is a potential target in the modem agricultural research towards understanding the molecular and cellular basis of drought tolerance. This study reports on the genomic and proteomic findings of drought tolerance in sorghum combining the results from in silica and experimental analysis. Pipeline that includes mapping expression data from 92 normalized cDNAs to genomic loci were used to identify drought tolerant genes. Integrative analysis was carried out using sequence similarity search, metabolic pathway, gene expression profiling and orthology relation to investigate genes of interest. Gene structure prediction was conducted using combination of ab initio and extrinsic evidence-driven information employing multi-criteria sources to improve accuracy. Gene ontology was used to cross-validate and to functionally assign and enrich genes. An integrated approach that subtly combines functional ontology based semantic data with expression profiling and biological networks was employed to analyse gene association with plant phenotypes and to identify and genetically dissect complex drought tolerance in sorghum. The gramene database was used to identify genes with direct or indirect association to drought related ontology terms in sorghum. Where direct association for sorghum genes were not available, genes were captured using Ensemble Biomart by transitive association based on the putative functions of sorghum orthologs in closely related species. Ontology mapping represented a direct or transitive association of genes to multiple drought related ontology terms based on sorghum specific genes or orthologs in related species. Correlation of genes to enriched gene ontology (GO)-terms (p-value < 0.05) related to the whole-plant structure was used to determine the extent of gene-phynotype association across-species and environmental stresses.
209

Změny proteinového profilu v průběhu sladování ječmene / Changes of protein profile in barley during malting

Šopíková, Martina January 2008 (has links)
This diploma thesis is focused on studies of changing of protein profile during barley malting. Substantial part of this work is devoted to the proteomics identification of barley proteins which change during malting and so become more stationary and they influence quality of beer (haze and foam in beer). For this experiment was used barley variety Jersey. In the theoretical part of this thesis there is information about beer, manufacturing of beer with description of important commodities for manufacturing of beer and information about barley malting and information about malting process. Next there is description of methods for separation of proteins (1D gel electrophoresis and 2D gel electrophoresis), MALDI TOF/TOF mass spectrometry and this use for the analysis and identification of proteins, the use of matrices and ways of the sample preparation. In the experimental part of this thesis there was carried out the optimisation of the dosage of sample for 1D gel electrophoresis and the optimisation of staining. The 15 % TRIS-HCl gel was the best, this gel was stained by Commassie Brilliant Blue G-250. For illustration of changes was made 2D gel electrophoresis. With help of method peptide mass fingerprinting and MS/MS protein of barley – protein Z, -amylase subtilisin inhibitor, -amylase a peroxidase were identificated. The analysis of barley extract intact proteins was carried out, this analysis was focused on changes of important barley protein LTP 1.
210

Analýza lipidů novorozeneckého mázku chromatografickými metodami a hmotnostní spektrometrií / Analysis of vernix caseosa lipids by chromatografic methods and mass spectrometry

Míková, Radka January 2016 (has links)
(EN) Vernix caseosa is a white creamy substance that covers the skin of a newborn. It is produced during the third trimester by the skin of the baby and remains there until the age of one or even two weeks. It is uniquely human. In utero, vernix protects the skin from maceration, during the birth it serves as a lubricant and after the delivery it protects the baby against infection and regulates the temperature. As vernix is produced in third trimester, prematurely born infants lack it and this may lead to, among other things, suffering from desiccation and therefore heat loss. It is important to study it thoroughly and to find a suitable substitute of vernix for the preterm infants. Vernix consists of lipids, proteins and 80 % water. This project is aimed at the lipids. Vernix is composed of 10 % of lipids. Basic analytical methods of pocessing vernix were searched. The methods of isolation, separation and transesterification have been optimized for the lipids. For separation, thin-layer chromatography has been chosen. The method of the lipid analysis of intact molecules by MALDI-TOF MS has been optimized for these lipids. The results were confirmed using fragmentation spectra and transesterification. Esterified lipids were measured by gas chromatography coupled with mass spectrometry detection....

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