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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.
101

Expression of AGBL1, DCPS, RUNX1 and PHYKPL in colorectal cancer

Siverling, Regina January 2022 (has links)
Colorectal cancer is one of the deadliest cancer forms because of late detection. Biomarkers can be used as an indication of cancer and plays of late a great role in cancer care, there are however currently no specific biomarkers that can be used for early detection of colorectal cancer. The genes AGBL1, DCPS, PHYKPL and RUNX1 have been suggested to be affected in colorectal cancer and the aim of this study was to investigate the expression of these in patients with colorectal cancer to understand more about the mechanisms involved in cancerogenesis. The gene expression in colorectal tumors and normal tissue was analysed by real-time PCR. Immunohistochemistry and western blot were used to analyse the expression of phosphorylated RUNX1 protein. The gene DCPS was downregulated by half and PHYKPL was downregulated about five times. RUNX1 was upregulated three times in the tumors, however, any active RUNX1-protein could not be detected in the tissue. Further studies are needed on these genes to fully understand their potential role in the disease and as prognostic markers.
102

Potential role of DcpS in colorectal cancer

Johansson, Gustaf January 2023 (has links)
No description available.
103

Application of Molecular Techniques to the Characterization of a Nitrifying Bioaugmentation Culture

Fouratt, Melissa Amanda 30 May 2001 (has links)
Nitrification is the biological process whereby ammonia is converted first to nitrite by ammonia-oxidizing bacteria, and then the nitrite is subsequently converted to nitrate by nitrite-oxidizing bacteria. Ammonia and nitrite levels are closely monitored during treatment of wastewater due to their toxicity to other biological processes. Sybron Chemicals, Inc., is a company that manufactures a nitrifying bioaugmentation culture (1010N) that is used to enhance the naturally occurring levels of biological nitrification. The microbial population of the 1010N product has been examined using a combination of conventional bacteriological methods and modern molecular techniques, with the goal of developing nucleic acid probes that can be used to detect the product in an environmental sample. Small regions of the 16S rRNA genes of the bacteria in 1010N (and two new nitrifying enrichment cultures) were amplified via the polymerase chain reaction (PCR) and analyzed via temperature gradient gel electrophoresis (TGGE). TGGE is a procedure that allows for separation and visualization of individual PCR products that are the same size, based on differences in their sequence. Two of the predominant PCR products in 1010N were purified from the TGGE gel matrix, reamplified via PCR, and sequenced to allow for phylogenetic analysis and nucleic acid probe design. Coincidentally, two strains (NS500-9 and MPN2) that had been isolated from the 1010N mixed consortium and grown in pure culture were found, via TGGE, to have identical 16S rRNA sequences to the PCR products under investigation. Nearly the full-length 16S rRNA genes from these two organisms were PCR amplified, cloned, and sequenced in order to provide a basis for more accurate phylogenetic analysis. The two dominant organisms in the 1010N product, NS500-9 and MPN2, were thereby found to be most closely related to Nitrosomonas and Nitrobacter, respectively, in the existing database. Using the nucleic acid sequences of the cloned DNA, organism-specific DNA probes were designed for both NS500-9 and MPN2. Unfortunately, difficulties were encountered in using the probes to monitor 1010N activity levels via quantitative dot blot hybridizations (rRNA-DNA). Therefore, efforts were redirected to using the TGGE semi-quantitatively with an internal PCR standard (Brüggeman, et al., 2000) to estimate original cell numbers of 1010N within a mixed consortium. This method was not applicable to our system due to substantial preferential binding of the primers to template other than the standard. Samples from a laboratory-scale bioreactor, bioaugmented with 1010N, were used in an attempt to correlate an increase in activity with a detectable shift in population via TGGE. No detectable shift in population was detected in these samples even though the system exhibited increased levels of nitrification. Therefore, the sensitivity of the TGGE system was also examined by determining the limits of detection when 1010N was present in activated sludge. In both whole cell spiking experiments and genomic DNA spiking experiments, it was found that 1010N must be present at a level of at least 5% of the total population in order to be detected. While this provides some information about microbial populations, in order to evaluate the biological activity of a system, nucleic acid probes should be used in a rRNA based study. / Master of Science
104

Towards Identifying Cis and Trans Regulators of Expression of Xylem Cysteine Protease 1 (XCP1) in Arabidopsis

Stroud, William Jefferson 04 June 2009 (has links)
Secondary xylem, commonly known as wood, is a valuable commercial commodity. Among the major components of wood are the elongated, thick-walled water-conducting cells known as tracheary elements. Understanding tracheary element differentiation and maturation is of scientific and commercial importance as it may lead to broad understanding of cellular differentiation processes as well as ways to increase both the quality and quantity of wood produced by economically important tree species. One way to begin to understand the regulation of tracheary element differentiation is to identify elements that control expression of genes associated with tracheary elements. In Arabidopsis thaliana, Xylem Cysteine Protease 1 (XCP1) is specifically expressed in tracheary elements where it catalyzes microautolysis. Thus XCP1 can serve as a useful model for identifying factors that regulate tracheary element-specific gene expression. A deletion analysis of the XCP1 promoter was conducted to identify promoter elements that are necessary and sufficient for tracheary element-restricted gene expression. Two regions required for tracheary element-specific gene expression were identified. One of these was assembled as a multimeric bait construct and used in yeast one-hybrid assays to identify candidate transcription factors that bind to the XCP1 promoter region. Subsequently, a southwestern blot analysis was used to identify transcription factors displaying specific binding to a previously reported cis-element, CTTCAAAGCCA, found in the XCP1 promoter and other tracheary element-associated genes from multiple species. / Master of Science
105

Interpretation of the Detection of Antibodies to Sarcocystis neurona in the serum and CSF of young horses

Cook, Anne Grimsley 02 July 2001 (has links)
Horses that are exposed to Sarcocystis neurona, a causative agent of equine protozoal myeloencephalitis, produce antibodies that are detectable in serum by western blot (WB). A positive test is indicative of exposure to the organism. Positive tests in young horses can be complicated by the presence of maternal antibodies. Passive transfer of maternal antibodies to S. neurona from seropositive mares to their foals was evaluated. Foals were sampled at birth (presuckle), at 24 hours of age (postsuckle), and at monthly intervals. All foals sampled before suckling were seronegative. Thirty-three foals from 33 seropositive mares became seropositive with colostrum ingestion at 24 hours of age, confirming that passive transfer of S. neurona maternal antibodies occurs. Thirty-one of the 33 foals became seronegative by 9 months of age, with a mean seronegative conversion time of 4.2 months. These results indicate that evaluation of exposure to S. neurona by WB analysis of serum may be misleading in young horses. Cerebrospinal fluid (CSF) samples from 15 neonatal (2-8 day) foals were examined for the presence of antibodies to S. neurona by WB analysis. Twelve of 13 foals that were seropositive were also CSF positive, suggesting that maternal antibodies to S. neurona cross the blood-CSF barrier in neonatal foals resulting in a positive CSF WB. Repeat taps were performed on 5 of the foals which showed that the immunoreactivity of the western blot decreases over time. Two of the 5 foals were CSF negative at 83 and 84 days of age, with 1 foal still positive at 90 days, and 2 foals positive at 62 days. These results indicate that maternal antibodies to S. neurona in the CSF can confound WB results in neonatal foals up to several months of age. / Master of Science
106

Distribution and Relative Abundance of Nutrient Transporter mRNA in the Gastrointestinal Tract of Black Bears

Gilbert, Elizabeth R. 18 August 2005 (has links)
Black bears are omnivorous, and tend to be opportunistic feeders, in that they will eat what is readily abundant or available. The end-products of intestinal digestion are absorbed by the body through the action of transporter proteins expressed on the brushborder membrane of small intestinal epithelial cells. The goal of this study was to increase the understanding of the physiological processes associated with nutrient assimilation by black bears. Distribution and relative abundance of mRNA of a peptide transporter (PepT1), a glucose transporter (SGLT1), two AA transporters (NBAT, bo,+AT), and a digestive enzyme, aminopeptidase N (APN), in the intestinal tract of black bears were investigated. Ten bears were used for this study. For tissue collection, the intestine was removed from the animal and divided into five sections. Each collected section was opened longitudinally, rinsed in ice-cold PBS, and the mucosal scrapings were stored at -80&#61616;C. Total RNA was extracted and quantified by spectrophotometry. Abundance of PepT1, SGLT1, NBAT, bo,+AT, and APN mRNA was determined by performing Northern blots, using bear cDNA probes. Northern blot data were quantified by densitometric analysis, with the abundance of each gene expressed relative to GAPDH. Abundance of PepT1 (P < 0.05), APN (P < 0.05), and SGLT1 (P < 0.0001) changed quadratically from the proximal to the distal intestine with abundance being greatest in the midregion. Abundance of bo,+AT mRNA increased linearly (P < 0.05) from the proximal to distal intestine. Abundance of NBAT mRNA did not change among intestinal segments.The absolute number of molecules of mRNA/ng of total RNA for each gene was determined using Real-Time PCR. Similar to the Northern results, abundance of PepT1 (P < 0.0003), SGLT1 (P < 0.0003), and APN (P < 0.02) changed quadratically from the proximal to distal intestine with abundance being greatest in the mid-region, and bo,+AT mRNA increased linearly (P < 0.0001) from the proximal to distal intestine. NBAT mRNA abundance also increased linearly (P < 0.0001) from proximal to distal intestine. PepT1 mRNA was present at tenfold or greater levels than AA transporter mRNA in all segments of the intestine, suggesting that di- and tripeptides constitute the major form in which AAs are absorbed. NBAT and bo,+AT mRNA abundance was greater towards the distal portion of the intestine, suggesting their importance in salvaging remaining unabsorbed AAs.These results indicate that the mRNA of nutrient transporters examined and APN are differentially expressed throughout the gastrointestinal tract of black bears, suggesting their involvement in nutrient assimilation. / Master of Science
107

Role of N-terminal residues of CCL19 and CCL21 in binding and activation of CCR7

Alotaibi, Mashael A.F.J. January 2021 (has links)
Chemokines are chemotactic cytokines, which mediate cell trafficking and play a key role in mobilisation of leukocytes. More recently, chemokines and their cognate receptors have been described as key players in different aspects of cancer biology contributing to proliferation, angiogenesis and metastasis. In particular, chemokines CCL19 and CCL21 acting on their associated receptor CCR7 are postulated to be key drivers of lymph node metastasis in a number of malignancies including breast, colon, gastric, & thyroid cancers. It has been reported that the cleavage of the pre-cysteine bridge N-terminal residues of CCL21 (SDGGAQD) and of CCL19 (GTNDAED) renders both peptides incapable of fully activating CCR7. However, little is known about the nature of the interactions that occur between the N-terminal residues of CCL19 or CCL21 and the CCR7 receptor, or the role they have in activation of CCR7. The aim of this study is to investigate the role of the residues in the N-terminus of CCL19 and in particular CCL21 in the context of CCR7 activation and to use this information in the discovery of novel CCR7 antagonists or agonists. To achieve this, we synthesised a number of short (three to seven amino acids) peptides and peptidomimetics inspired by the seven N-terminal amino acid residues of CCL19 and CCL21 and pharmacologically characterised their ability to activate CCR7 or block the activation of CCR7 using a number of in vitro assays such as calcium flux, trans-well (Boyden chamber), and Western blotting. We also carried out computational studies to better understand and predict the activity of these peptides. Our results demonstrate that some of these peptides are indeed capable of acting as agonists or antagonists of CCR7. / Kuwait Health Ministry and Kuwait Civil Services Commission
108

Optimization of a monoclonal antibody “Pwlam” for use to diagnose AL Amyloidosis

Arvidsson, Philip January 2024 (has links)
Amyloidosis is a group of diseases that originate from misfolded proteins. These proteins form fibrils which is stored in the tissue and organs. Approximately three to twelve per million people are diagnosed with amyloid light chain immunoglobulin amyloidosis (AL) each year and the median age is 65. The prognosis for AL amyloidosis is poor with a median survival rate of six months to three years. The patients may survive an additional 15-20 years with treatment such as stem cell transplantation.   The aim of this rapport was to optimize a monoclonal antibody named pwlam to diagnose AL λ amyloid with immunohistochemistry (IHC) when the amount of sample is small. In this rapport three different methods were used, pressure preparation, IHC and western blot. For both pressure preparation and IHC, colour development occurred in case of positive results. Western blot was used as a quality control for the tissue since they were all originally diagnosed using that method.    A total of 26 samples were tested, 16 positive AL λ samples, five AL κ samples and five negative samples. Pwlam is developed against AL λ so the AL κ samples function as a quality control for the antibody since it doesn’t bind to the κ light chains. A total of seven AL λ samples had a good binding with pwlam. More research is needed before pwlam can be used in IHC on pressure preparations as a supplementary method to diagnose samples when the amount of AL λ amyloid is small.
109

Differentielle Genexpressionsanalyse aktivierter Endothelzellen / Differential genexpression-analysis of activated endothelial cells

Schmidt, Tobias 30 April 2001 (has links)
No description available.
110

Prevalence analysis of putative periodontal pathogens in patients with aggressive periodontitis and healthy elderly

Edesi-Neuss, Lilian 21 November 2005 (has links)
Marginale Parodontitis, die multikausale Erkrankung des Parodonts ist eine Infektionskrankheit, modifiziert durch Wirtsfaktoren und äußere Einflüße. Die als pathogene Mischflora bezeichnete Kombination kommensaler Mikroorganismen spielt die primäre Rolle in der Ätiopathogenese der Parodontitis. In der Aufstellung des Studienziels wurden einzelne Bakterienarten (T. forsythensis, P. gingivalis, A. actinomycetemcomitans, C. rectus, F. nucleatum, Fusobacterium spp., P. intermedia, E. corrodens, V. parvula und C. ochracea) ausgewählt, die eventuell als "Markerkeime" in der aggressiven Form der Parodontitis betrachtet werden können. Dazu wurde eine Kontrollgruppe untersucht, die eine gesunde parodontale Flora besitzt. Die angewandte Nachweismethode basiert auf der PCR-Amplifikation von 16S rDNA und darauffolgender dot-blot Hybridisierung mit Oligonukleotidsonden. Die entsprechenden Sonden wurden hergestellt, optimiert und evaluiert. Für die epidemiologische Untersuchung wurde subgingivale Plaque von vier Parodontaltaschen und einer Kontrollstelle von 45 Patienten mit aggressiver Parodontitis, sowie an fünf Stellen von 21 Senioren entnommen. Die Prävalenz der einzelnen Bakterienarten wurde mit Hilfe des Chi-Quadrat Test verglichen. Obgleich eine hohe interindividuelle Variabilität der Kolonisationsmuster zu beobachten war, konnten T. forsythensis, P. gingivalis, C. rectus und F. nucleatum signifikant häufiger in den Parodontaltaschen als an den gesunden Stellen nachgewiesen werden und können deswegen als "Leitkeime" der aggressiven Parodontitis angesehen werden. A. actinomycetemcomitans konnte nur bei einzelnen Patienten mit aggressiver Parodontitis festgestellt werden. Die Ergebnisse für P. intermedia und E. corrodens ließen keine eindeutige Assoziation sowohl mit der aggressiven Parodontitis als auch mit dem gesunden Parodontalzustand zu. Bei Senioren wurde C. ochracea besonders häufig nachgewiesen. Die Ergebnisse dieser Studie bewiesen die erfolgreiche Einsetzbarkeit der hergestellten Oligonukleotidsonden. / A multifactorial risk pattern of periodontitis has been recognized, where in addition to host and environmental factors, a pathogenic microbiota plays a primary role. The purpose of the current research was to analyze the prevalence of periodontitis-associated microorganisms in patients with aggressive periodontitis and periodontally healthy elders by using molecular-biologic detection methods like eubacterial PCR-amplification of 16S rDNA in combination with dot-blot hybridization. The oligonucleotide probes for the detection of T. forsythensis, P. gingivalis, A. actinomycetemcomitans, C. rectus, F. nucleatum, Fusobacterium spp., P. intermedia, E. corrodens, V. parvula and C. ochracea were designed and evaluated. The PCR products of 42 cultivated target and closely related bacteria were used for the optimization of hybridization conditions. For the epidemiological study, subgingival plaque was sampled from four pockets and one healthy site of 45 aggressive periodontitis patients as well as from five sites of 21 elderly. The differences in the prevalence of bacterial species were analyzed by the chi-square test. The data revealed frequent colonization by T. forsythensis, P. gingivalis, F. nucleatum and C. rectus in patients with aggressive periodontitis, however individual variations were obvious. These species could be predominantly identified in periodontal pockets, but were significantly less common in the healthy sites of the periodontitis patients and in the elderly. These putative pathogens can be conclusively determined as the key-bacteria in patients with aggressive periodontitis. No direct association for P. intermedia and E. corrodens with aggressive periodontitis or periodontal health could be seen. A. actinomycetemcomitans could be detected in only a few patients, reducing its suspected importance in the etiology of aggressive periodontitis. C. ochracea was highly prevalent in the well-maintained elderly, suggesting its association with healthy flora. The results of the study confirmed the reliability of the oligonucleotide probes in a specific and sensitive detection of the respective oral species.

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