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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.
51

Antibody-based Profiling of Expression Patterns using Cell and Tissue Microarrays

Strömberg, Sara January 2008 (has links)
In this thesis, methods to study gene and protein expression in cells and tissues were developed and utilized in combination with protein-specific antibodies, with the overall objective to attain greater understanding of protein function. To analyze protein expression in in vitro cultured cell lines, a cell microarray (CMA) was developed, facilitating antibody-based protein profiling of cell lines using immunohistochemistry (IHC). Staining patterns in cell lines were analyzed using image analysis, developed to automatically identify cells and immunohistochemical staining, providing qualitative and quantitative measurements of protein expression. Quantitative IHC data from CMAs stained with nearly 3000 antibodies was used to evaluate the adequacy of using cell lines as models for cancer tissue. We found that cell lines are homogenous with respect to protein expression profiles, and generally more alike each other, than corresponding cancer cells in vivo. However, we found variability between cell lines in regards to the level of retained tumor phenotypic traits, and identified cell lines with a preserved link to corresponding cancer, suggesting that some cell lines are appropriate model systems for specific tumor types. Specific gene expression patterns were analyzed in vitiligo vulgaris and malignant melanoma. Transcriptional profiling of vitiligo melanocytes revealed dysregulation of genes involved in melanin biosynthesis and melanosome function, thus highlighting some mechanisms possibly involved in the pathogenesis of vitiligo. Two new potential markers for infiltrating malignant melanoma, Syntaxin-7 and Discs large homolog 5, were identified using antibody-based protein profiling of melanoma in a tissue microarray format. Both proteins were expressed with high specificity in melanocytic lesions, and loss of Syntaxin-7 expression was associated with more high-grade malignant melanomas. In conclusion, the combination of antibody-based proteomics and microarray technology provided valuable information of expression patterns in cells and tissues, which can be used to better understand associations between protein signatures and disease.
52

The Mutagenic Activity of High-Energy Explosives; Contaminants of Concern at Military Training Sites

McAllister, Jennifer E. 24 August 2011 (has links)
The genotoxicity of energetic compounds (i.e., explosives) that are known to be present in contaminated soils at military training sites has not been extensively investigated. Thus, the Salmonella mutagenicity and Muta(TM)Mouse assays were employed as in vitro assays to examine the mutagenic activity of twelve explosive compounds, as well as three soil samples from Canadian Forces Base Petawawa. Salmonella analyses employed strains TA98 (frameshift mutations) and TA100 (base-pair substitution mutations), as well as the metabolically-enhanced YG1041 (TA98 background) and YG1042 (TA100 background), with and without exogenous metabolic activation (S9). For Salmonella analyses, the results indicate that ten of the explosive compounds were mutagenic, and consistently elicited direct-acting, base-pair substitution activity. All three soil samples were also observed to be mutagenic, eliciting direct-acting, frameshift activity. Mutagenic potencies were significantly higher on the metabolically-enhanced strains for all compounds and soil samples. For Muta(TM)Mouse analyses on FE1 cells, the results indicate that the majority of explosive compounds did not exhibit mutagenic activity. All three soil samples elicited significant positive responses (PET 1 and PET 3 without S9, and PET 2 with S9), and although there is some evidence of a concentration-related trend, the responses were weak. Correspondence of the mutagenic activity observed with the two assay systems, for both the explosive compounds and soil samples, was negligible. The differential response is likely due to differences in metabolic capacity between the two assay systems. Furthermore, it is likely that there are unidentified compounds present in these soil samples that are, at least in part, responsible for the observed mutagenic activity. Additional testing of other explosive compounds, as well as soil samples from other military training sites, using a variety of in vitro and in vivo assays, is warranted in order to reliably estimate mutagenic hazard and subsequently assess risk to human health.
53

Radiosensitizing glioblastoma in a rat model using l-buthionine-sr-sulfoximine (BSO)

Ataelmannan, Khalid Ali 21 April 2008
Glioblastoma multiforme (GBM) is the most aggressive and most common primary brain tumor in adults accounting for 50-60% of primary brain tumors. The prognosis for patients with GBM remains poor and treatment is mainly palliative with a mean survival time of less than one year. Radiotherapy is used extensively in the management of glioblastoma either alone or in combination with surgery and/or chemotherapy. However, this tumor is one of the most resistant tumors to radiotherapy thus limiting the benefit of this form of treatment. <p>Studies have shown that malignant tumors have a high content of glutathione an antioxidant responsible for protecting the cells against damage from free radicals (mainly superoxide, hydroxyl and hydrogen peroxide). It is well established that glutathione, by neutralizing these free radicals plays a major role in radioresistance. Glioblastoma has relatively high levels of glutathione. In this study, by reducing the glutathione content of glioblastoma in a rat model, we were able to investigate the effect of this reduction in enhancing the effect of radiotherapy as a form of treatment for glioblastoma multiforme in a rat model. <p>By injecting L-Buthionine-SR-Sulfoximine (BSO) in to the tumor tissue, the glutathione content of the tumor was reduced by about 70% of its initial value. When administered into the tumors 2 hours prior to radiotherapy the animals so treated had a significantly longer median survival time compared with animals that received radiotherapy alone.
54

Characterization and encapsulation of probiotic bacteria using a Pea-protein Alginate matrix

Kotikalapudi, Bhagya Lakshmi 24 September 2009
Research was undertaken to examine different <i>in vitro</i> characteristics of probiotic bacteria, including <i>Lactobacillus acidophilus</i> ATCC® 11975, <i>Bifidobacterium infantis</i> ATCC 15697D, <i>Bifidobacterium catenulatum</i> ATCC® 27675 and <i>Bifidobacterium adolescentis</i> ATCC® 15703 in order to identify suitable strain(s) for encapsulation. Under simulated gastric conditions (pH 2.0), <i>L. acidophilus</i> was the most acid-tolerant strain (D-value 10.2 ± 0.8 min), and was able to survive for 30 min; whereas, the other tested probiotics underwent a rapid (within the first 5 min at pH 2.0) 4-5 log colony forming units (cfu)/mL loss in viability. All probiotics tested were able to survive 5 h exposure to 0.3% Oxgall bile at pH 5.8. The relative ranking of probiotic adherence to Caco-2 cells was determined to be: <i>L. acidophilus</i> > <i>B. catenulatum</i> > <i>B. adolescentis</i> > <i>B. infantis</i>, which correlated with 4.5 104, 3.1 103, 2.6 101, and 1.5 101 cfu/mL associated with Caco-2 cell monolayers, respectively. The most hydrophobic probiotics included <i>L. acidophilus</i> (46.5 ± 6.1%) and B. catenulatum (65.5 ± 5.2%); their hydrophobicity were positively correlated with auto-aggregation ability. Addition of divalent cations, EDTA, and bile salts were found to affect hydrophobicity as well; for example, 0.5 mM MgCl2 resulted in a 20% increase in cell surface hydrophobicity of <i>L. acidophilus</i> from baseline levels; whereas, the addition of 0.1 and 0.5% bile salts decreased <i>L. acidophilus</i> hydrophobicity from control levels by 60 and 90%, respectively. Cell free culture supernatant of <i>L. acidophilus</i> effectively inhibited the growth of <i>Escherichia coli</i> O157:H7, and <i>Clostridium sordelli</i>. Bactericidal activity of <i>L. acidophilus</i> cell-free supernatant (the lethal factor was determined to be both heat and trypsin-resistant) against Escherichia coli O157:H7 and <i>Clostridium sordelli</i> ATCC 9714 over 24 h resulted in reductions of 5.5 and 3.5 log cfu/mL, respectively. Further examination of probiotics revealed varying degrees of resistance to the iv antimicrobial agents ciprofloxacin (4 ìg/mL), naladixic acid (32 ìg/mL), kanamycin (64 ìg/mL) and sulfisoxazone (256 ìg/mL). Determination of carbon source utilization patterns indicated that <i>B. catenulatum</i> utilized a number of carbohydrates including -methyl-D-glucoside, D-xylose, D-cellobiose, and -D-lactose; whereas,<i>L. acidophilus, B. infantis</i>, and <i>B. adolescentis</i> utilized D-xylose. <i>Lactobacillus acidophilus</i> was ultimately selected for encapsulation in a 3 mm diameter pea protein-alginate matrix followed by <i>in vitro</i> challenge to simulated gastric conditions (pH 2.0). Encapsulation of <i>L. acidophilus</i> demonstrated a significant (P < 0.05) protective effect during the 2 h exposure to simulated acidic stomach conditions; within capsules, there was approximately 1 log cfu/mL loss in cell viability, whereas unprotected cells experienced > 6 log/mL loss in cell viability over the same period.
55

Establishment and Characterization of Immortalized Non-Transplantable Mouse Mammary Cell Lines Cloned from a MMTV-induced Tumor Cell Line Cultured for A Long Duration

HOSHINO, MUNEMITSU, MATSUYAMA, MUTSUSHI, TAGUCHI, OSAMU, KUSAKABE, MORIAKI, WAJJWALKU, WORAWIDH, LU, JIN, YOKOI, TOYOHARU, IMAI, MASAO, MIYAISHI, OSAMU, SAGA, SHINSUKE, TAKENAKA, TOKUYA 03 1900 (has links)
名古屋大学博士学位論文 学位の種類 : 博士(医学)(課程) 学位授与年月日:平成2年11月22日 竹中徳哉氏の博士論文として提出された
56

The Mutagenic Activity of High-Energy Explosives; Contaminants of Concern at Military Training Sites

McAllister, Jennifer E. 24 August 2011 (has links)
The genotoxicity of energetic compounds (i.e., explosives) that are known to be present in contaminated soils at military training sites has not been extensively investigated. Thus, the Salmonella mutagenicity and Muta(TM)Mouse assays were employed as in vitro assays to examine the mutagenic activity of twelve explosive compounds, as well as three soil samples from Canadian Forces Base Petawawa. Salmonella analyses employed strains TA98 (frameshift mutations) and TA100 (base-pair substitution mutations), as well as the metabolically-enhanced YG1041 (TA98 background) and YG1042 (TA100 background), with and without exogenous metabolic activation (S9). For Salmonella analyses, the results indicate that ten of the explosive compounds were mutagenic, and consistently elicited direct-acting, base-pair substitution activity. All three soil samples were also observed to be mutagenic, eliciting direct-acting, frameshift activity. Mutagenic potencies were significantly higher on the metabolically-enhanced strains for all compounds and soil samples. For Muta(TM)Mouse analyses on FE1 cells, the results indicate that the majority of explosive compounds did not exhibit mutagenic activity. All three soil samples elicited significant positive responses (PET 1 and PET 3 without S9, and PET 2 with S9), and although there is some evidence of a concentration-related trend, the responses were weak. Correspondence of the mutagenic activity observed with the two assay systems, for both the explosive compounds and soil samples, was negligible. The differential response is likely due to differences in metabolic capacity between the two assay systems. Furthermore, it is likely that there are unidentified compounds present in these soil samples that are, at least in part, responsible for the observed mutagenic activity. Additional testing of other explosive compounds, as well as soil samples from other military training sites, using a variety of in vitro and in vivo assays, is warranted in order to reliably estimate mutagenic hazard and subsequently assess risk to human health.
57

Radiosensitizing glioblastoma in a rat model using l-buthionine-sr-sulfoximine (BSO)

Ataelmannan, Khalid Ali 21 April 2008 (has links)
Glioblastoma multiforme (GBM) is the most aggressive and most common primary brain tumor in adults accounting for 50-60% of primary brain tumors. The prognosis for patients with GBM remains poor and treatment is mainly palliative with a mean survival time of less than one year. Radiotherapy is used extensively in the management of glioblastoma either alone or in combination with surgery and/or chemotherapy. However, this tumor is one of the most resistant tumors to radiotherapy thus limiting the benefit of this form of treatment. <p>Studies have shown that malignant tumors have a high content of glutathione an antioxidant responsible for protecting the cells against damage from free radicals (mainly superoxide, hydroxyl and hydrogen peroxide). It is well established that glutathione, by neutralizing these free radicals plays a major role in radioresistance. Glioblastoma has relatively high levels of glutathione. In this study, by reducing the glutathione content of glioblastoma in a rat model, we were able to investigate the effect of this reduction in enhancing the effect of radiotherapy as a form of treatment for glioblastoma multiforme in a rat model. <p>By injecting L-Buthionine-SR-Sulfoximine (BSO) in to the tumor tissue, the glutathione content of the tumor was reduced by about 70% of its initial value. When administered into the tumors 2 hours prior to radiotherapy the animals so treated had a significantly longer median survival time compared with animals that received radiotherapy alone.
58

Characterization and encapsulation of probiotic bacteria using a Pea-protein Alginate matrix

Kotikalapudi, Bhagya Lakshmi 24 September 2009 (has links)
Research was undertaken to examine different <i>in vitro</i> characteristics of probiotic bacteria, including <i>Lactobacillus acidophilus</i> ATCC® 11975, <i>Bifidobacterium infantis</i> ATCC 15697D, <i>Bifidobacterium catenulatum</i> ATCC® 27675 and <i>Bifidobacterium adolescentis</i> ATCC® 15703 in order to identify suitable strain(s) for encapsulation. Under simulated gastric conditions (pH 2.0), <i>L. acidophilus</i> was the most acid-tolerant strain (D-value 10.2 ± 0.8 min), and was able to survive for 30 min; whereas, the other tested probiotics underwent a rapid (within the first 5 min at pH 2.0) 4-5 log colony forming units (cfu)/mL loss in viability. All probiotics tested were able to survive 5 h exposure to 0.3% Oxgall bile at pH 5.8. The relative ranking of probiotic adherence to Caco-2 cells was determined to be: <i>L. acidophilus</i> > <i>B. catenulatum</i> > <i>B. adolescentis</i> > <i>B. infantis</i>, which correlated with 4.5 104, 3.1 103, 2.6 101, and 1.5 101 cfu/mL associated with Caco-2 cell monolayers, respectively. The most hydrophobic probiotics included <i>L. acidophilus</i> (46.5 ± 6.1%) and B. catenulatum (65.5 ± 5.2%); their hydrophobicity were positively correlated with auto-aggregation ability. Addition of divalent cations, EDTA, and bile salts were found to affect hydrophobicity as well; for example, 0.5 mM MgCl2 resulted in a 20% increase in cell surface hydrophobicity of <i>L. acidophilus</i> from baseline levels; whereas, the addition of 0.1 and 0.5% bile salts decreased <i>L. acidophilus</i> hydrophobicity from control levels by 60 and 90%, respectively. Cell free culture supernatant of <i>L. acidophilus</i> effectively inhibited the growth of <i>Escherichia coli</i> O157:H7, and <i>Clostridium sordelli</i>. Bactericidal activity of <i>L. acidophilus</i> cell-free supernatant (the lethal factor was determined to be both heat and trypsin-resistant) against Escherichia coli O157:H7 and <i>Clostridium sordelli</i> ATCC 9714 over 24 h resulted in reductions of 5.5 and 3.5 log cfu/mL, respectively. Further examination of probiotics revealed varying degrees of resistance to the iv antimicrobial agents ciprofloxacin (4 ìg/mL), naladixic acid (32 ìg/mL), kanamycin (64 ìg/mL) and sulfisoxazone (256 ìg/mL). Determination of carbon source utilization patterns indicated that <i>B. catenulatum</i> utilized a number of carbohydrates including -methyl-D-glucoside, D-xylose, D-cellobiose, and -D-lactose; whereas,<i>L. acidophilus, B. infantis</i>, and <i>B. adolescentis</i> utilized D-xylose. <i>Lactobacillus acidophilus</i> was ultimately selected for encapsulation in a 3 mm diameter pea protein-alginate matrix followed by <i>in vitro</i> challenge to simulated gastric conditions (pH 2.0). Encapsulation of <i>L. acidophilus</i> demonstrated a significant (P < 0.05) protective effect during the 2 h exposure to simulated acidic stomach conditions; within capsules, there was approximately 1 log cfu/mL loss in cell viability, whereas unprotected cells experienced > 6 log/mL loss in cell viability over the same period.
59

Effects of glial cell line-derived neurotrophic factor (GDNF) on mouse fetal ventral mesencephalic tissue

Nevalainen, Nina January 2008 (has links)
The symptoms of Parkinson's disease occur due to degeneration of dopamine neurons in substantia nigra. It has been demonstrated that glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor when it comes to protect and enhance survival of dopamine neurons in animal models of Parkinson's disease. The aim of this study was to evaluate short- and long-term effects of GDNF on survival and nerve fiber outgrowth of dopamine cells and astrocytic migration in mouse fetal ventral mesencephalic (VM) tissue. Primary tissue cultures were made of mouse fetal VM tissue and evaluated at 7 and 21 days in vitro (DIV) in terms of dopaminergic nerve fiber outgrowth and astrocytic migration when developed with GDNF present, partially, or completely absent. The results revealed that VM tissue cultured in the absence of GDNF did not exhibit any significant differences in migration of astrocytes or dopaminergic nerve fiber outgrowth neither after 7 DIV nor after 21 DIV, when compared with tissue cultured with GDNF present. Migration of astrocytes and dopaminergic nerve fiber outgrowth reached longer distances when tissue was left to develop for 21 DIV in comparison with 7 DIV. In order to study the long-term effects of GDNF, mouse fetal dopaminergic tissue was transplanted into the ventricles of adult mice and evaluated after 6 months. No surviving dopamine neurons were present in the absence of GDNF. In contrast dopamine neurons developed with GDNF did survive, indicating that GDNF is an essential neurotrophic factor when it comes to long-term dopamine cell survival. More cases have to be assessed in the future in order to strengthen the findings. Thus, transplanted dopamine neurons will be assessed after 3 and 12 months in order to map out when dopamine neurons deprived of GDNF undergo degeneration.
60

Histone upregulation may contribute to cytotoxicity in spinal muscular atrophy : Examination of smn1 knockdown in the P19 cell line. / Uppreglering av histoner kan vara grund till cytotoxiciteten i spinal muscular atrophy

Samrani, George January 2012 (has links)
No description available.

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