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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.
81

Inhibition of NAMPT sensitizes MOLT4 leukemia cells for etoposide treatment through the SIRT2-p53 pathway

Grohmann, Theresa, Penke, Melanie, Petzold-Quinque, Stefanie, Schuster, Susanne, Richter, Sandy, Kiess, Wieland, Garten, Antje 02 March 2020 (has links)
NAMPT (Nicotinamide phosphoribosyltransferase) catalyses the rate-limiting step in the NAD biosynthesis from nicotinamide and thereby regulates the activity of NAD-dependent enzymes. Cancer cells are highly dependent on NAD for energy and DNA repair processes and are assumed to be more susceptible to an inhibition of NAD synthesis than non-transformed cells. We aimed to investigate whether or not inhibition of NAMPT with its specific inhibitor FK866 can sensitize leukemia cells for chemotherapeutic agents. NAMPT protein abundance, enzymatic activity and NAD concentrations were significantly higher in Jurkat and Molt-4 leukemia cell lines compared to normal peripheral blood mononuclear cells. Combination of etoposide and FK866 caused increased cell death in leukemia cell lines compared to etoposide alone. Etoposide decreased protein abundance of NAD-dependent deacetylases SIRTUIN1. After combining etoposide and FK866 treatment SIRTUIN2 was further decreased and accumulation and acetylation of the downstream target p53 was further enhanced in MOLT4 cells. Concomitantly, protein abundance of p21 and cleaved BAX was increased. Targeting NAMPT could be a novel therapeutic strategy to enhance the efficacy of chemotherapeutic agents such as etoposide against leukemia.
82

B-CELL LYMPHOMA-2 PROTEIN FAMILY, APOPTOSIS AND THE ENDOPLASMIC RETICULUM

Thomenius, Michael James 06 April 2004 (has links)
No description available.
83

Bax-Inhibitor-1-vermittelte Neuroprotektion / Bax-Inhibitor-1 mediated neuroprotection

Siedenberg, Sandra 26 June 2007 (has links)
No description available.
84

Darmschädigung durch Photonen-Strahlung nach Einzeitbestrahlung der Leber / Radiation-induced damage in different segments of the rat intestine after external

Schwartz, Antonia 16 January 2012 (has links)
No description available.
85

Fetal Outcome in Experimental Diabetic Pregnancy

Zabihi, Sheller January 2008 (has links)
<p>Women with pregestational diabetes have a 2-5 fold increased risk of giving birth to malformed babies compared with non-diabetic women. Diabetes-induced oxidative stress in maternal and embryonic tissues has been implicated in the teratogenic process. The malformations are likely to be induced before the seventh week of pregnancy, when the yolk sac is partly responsible for the transfer of metabolites to the embryo, and the uterine blood flow to the implantation site determines the net amount of nutrients available to the conceptus. We aimed to evaluate the effect on embryogenesis caused by a diabetes-induced disturbance in yolk sac morphology, uterine blood flow or altered maternal antioxidative status in conjunction with a varied severity of the maternal diabetic state.</p><p>We investigated to which extent maternal diabetes with or without folic acid (FA) supplementation affects mRNA levels and protein distribution of ROS scavenging enzymes (SOD, CAT, GPX), vascular endothelial growth factor-A (Vegf-A), folate binding protein-1 (Folbp-1), and apoptosis associated proteins (Bax, Bcl-2, Caspase-3) in the yolk sacs of rat embryos on gestational days 10 and 11. We found that maternal diabetes impairs, and that FA supplementation restores, yolk sac vessel morphology, and that maternal diabetes is associated with increased apoptotic rate in embryos and yolk sacs, as well as impaired SOD gene expression. We assessed uterine blood flow with a laser-Doppler-flow-meter and found increased blood flow to implantation sites of diabetic rats compared with controls. Furthermore, resorbed and malformed offspring showed increased and decreased blood flow to their implantation sites, respectively. In mice with genetically altered CuZnSOD levels, maternal diabetes increased embryonic dysmorphogenesis irrespective of CuZnSOD expression. We thus found the maternal diabetic state to be a major determinant of diabetic embryopathy and that the CuZnSOD status exerts a partial protection for the embryo in diabetic pregnancy. </p>
86

Vztah mezi genetickými polymorfismy DNA reparačních genů a jejich expresí u zdravé populace (s výhledem na stanovení u onkologických pacientů). / Vztah mezi genetickými polymorfismy DNA reparačních genů a jejich expresí u zdravé populace (s výhledem na stanovení u onkologických pacientů).

Hánová, Monika January 2013 (has links)
DNA damage response is a complex system responsible for protection of a cell against internal and external DNA damaging agents and in maintaining genome integrity. Many of genes participating in DNA damage response pathways are polymorphic. Genetic polymorphisms in coding and regulatory regions may have impact on the function of proteins encoded by the genes. Phenotypic effect of single nucleotide polymorphisms (SNPs) is subject of investigation in connection with the ability of a cell to manage genotoxic stress and subsequently, in relation to cancer susceptibility. The aim of this thesis was to evaluate the association between SNPs in DNA repair genes (hOGG1, XRCC1, XPC) and cell cycle genes (TP53, p21CDKN1A , BCL2 and BAX) and their mRNA expression in peripheral blood lymphocytes from individuals occupationally exposed to styrene and control individuals. The aim was extended to analyses of relationships between mRNA expression levels of the above-mentioned genes and markers of exposure to styrene (concentration of styrene in blood and in air), markers of DNA damage (single strand breaks - SSBs, and endonuclease III specific sites - Endo III sites) and the base excision repair (BER) capacity, by means of γ-irradiation specific DNA repair rates and oxidative repair. Study on the group of healthy...
87

Prognostic Factors in Early Stages (FIGO I-II) of Epithelial Ovarian Carcinoma

Skírnisdóttir, Ingirídur January 2002 (has links)
<p>From January, 1988, to December, 1993, 113 patients with FIGO stage IA-IIC epithelial ovarian carcinoma were treated with postoperative radiotherapy. The median follow-up period was 74 months. Tumor recurrences were recorded in 33 cases (30%). The cancer-specific survival rate was 72%. Tumor grade was a significant (P = 0.007) and independent prognostic factor in the multivariate analysis. In a smaller series of 106 patients, a number of prognostic factors (age, FIGO stage, histopathological type, and tumor grade) were studied in relation to regulators of apoptosis (p53, bcl-2, and bax) and growth factor receptors (HER-2/neu and EGFR). Immunohistochemical techniques were used. In a separate series of 103 patients, the DNA content (flow cytometry) and p53 status of the tumors were also studied and related to the same clinicopathological factors. P53 was associated with tumor grade (P = 0.007) and survival status (P = 0.046). In a Cox multivariate analysis, tumor grade (P = 0.0006), bax status (P = 0.020), and EGFR status (P = 0.018) were significant and independent prognostic factors. DNA ploidy of the tumors was strongly associated with tumor grade. </p><p>From January, 1994, to December, 1998, a series of 109 patients with ovarian carcinomas (FIGO IA-IIC) were treated with postoperative adjuvant chemotherapy. The same prognostic factors were studied in this series. The median follow-up was 48 months and the cancer-specific survival rate was 75%. Twenty-five (25%) tumor recurrences were recorded. The most favorable survival rate was seen in patients with tumors negative for p53 and positive for bcl-2 or bax. In a multivariate analysis, tumor grade (P = 0.014) and p53 status (P = 0.020) were independent prognostic factors.</p><p>Clinical, histopathological and biological prognostic factors should be combined in prognostic models to render patient-tailored therapy possible and to define different prognostic groups for future clinical studies of adjuvant therapy in early stage ovarian carcinomas.</p>
88

On pathophysiological mechanisms in amyothrophic lateral sclerosis

Grundström, Eva January 2000 (has links)
<p>Amyotrophic lateral sclerosis is a fatal, progressive neurodegenerative disease with unknown ethiology. The aim of this study was to increase understanding of the pathophysiological mechanisms of dying motor neurons and wasting muscle tissue in this particular disorder.</p><p>Quantitative receptor autoradiographic methodology was applied on cervical spinal cord sections from patients with ALS to evaluate the specific binding of the acetylcholine transporter <sup>3</sup>H-vesamicol in motor neurons. Despite a significant reduction of the number of ventral motor neurons in ALS, the <sup>3</sup>H-vesamicol binding was not reduced in ALS compared to control cases, which suggests an increased metabolic activity in remaining motor neurons.</p><p>Motor neurons dying in ALS might go through apoptosis (programmed cell death), so immunohistochemical and TUNEL techniques were applied on thoracic spinal cord from ALS patients to evaluate the possibility of an apoptotic process. The increased Bax expression indicates an apoptotic process and further, motor neurons were TUNEL-positive, indicating DNA degradation caused by programmed cell death.</p><p>Muscle biopsies were obtained from ALS patients, and mRNA levels for the neurotrophic factors GDNF and BDNF were measured and compared to control subjects. GDNF levels were increased in muscle tissue in ALS whereas BDNF levels were unaltered.</p><p>Levels of GDNF and BDNF were also measured in cerebrospinal fluid from ALS patients and controls using ELISA methodology. Levels of BDNF were unaltered in ALS cornpared to controls. GDNF however was not detectable in controls whereas 12 out of 15 ALS patients had measurab1e levels of GDNW. A marked upregulation of endogenous GDNF and GDNF mRNA in ALS CSF and muscle respectively is of special interest in relation to clinical trials where GDNF is administered to this group of patients.</p>
89

On pathophysiological mechanisms in amyothrophic lateral sclerosis

Grundström, Eva January 2000 (has links)
Amyotrophic lateral sclerosis is a fatal, progressive neurodegenerative disease with unknown ethiology. The aim of this study was to increase understanding of the pathophysiological mechanisms of dying motor neurons and wasting muscle tissue in this particular disorder. Quantitative receptor autoradiographic methodology was applied on cervical spinal cord sections from patients with ALS to evaluate the specific binding of the acetylcholine transporter 3H-vesamicol in motor neurons. Despite a significant reduction of the number of ventral motor neurons in ALS, the 3H-vesamicol binding was not reduced in ALS compared to control cases, which suggests an increased metabolic activity in remaining motor neurons. Motor neurons dying in ALS might go through apoptosis (programmed cell death), so immunohistochemical and TUNEL techniques were applied on thoracic spinal cord from ALS patients to evaluate the possibility of an apoptotic process. The increased Bax expression indicates an apoptotic process and further, motor neurons were TUNEL-positive, indicating DNA degradation caused by programmed cell death. Muscle biopsies were obtained from ALS patients, and mRNA levels for the neurotrophic factors GDNF and BDNF were measured and compared to control subjects. GDNF levels were increased in muscle tissue in ALS whereas BDNF levels were unaltered. Levels of GDNF and BDNF were also measured in cerebrospinal fluid from ALS patients and controls using ELISA methodology. Levels of BDNF were unaltered in ALS cornpared to controls. GDNF however was not detectable in controls whereas 12 out of 15 ALS patients had measurab1e levels of GDNW. A marked upregulation of endogenous GDNF and GDNF mRNA in ALS CSF and muscle respectively is of special interest in relation to clinical trials where GDNF is administered to this group of patients.
90

Prognostic Factors in Early Stages (FIGO I-II) of Epithelial Ovarian Carcinoma

Skírnisdóttir, Ingirídur January 2002 (has links)
From January, 1988, to December, 1993, 113 patients with FIGO stage IA-IIC epithelial ovarian carcinoma were treated with postoperative radiotherapy. The median follow-up period was 74 months. Tumor recurrences were recorded in 33 cases (30%). The cancer-specific survival rate was 72%. Tumor grade was a significant (P = 0.007) and independent prognostic factor in the multivariate analysis. In a smaller series of 106 patients, a number of prognostic factors (age, FIGO stage, histopathological type, and tumor grade) were studied in relation to regulators of apoptosis (p53, bcl-2, and bax) and growth factor receptors (HER-2/neu and EGFR). Immunohistochemical techniques were used. In a separate series of 103 patients, the DNA content (flow cytometry) and p53 status of the tumors were also studied and related to the same clinicopathological factors. P53 was associated with tumor grade (P = 0.007) and survival status (P = 0.046). In a Cox multivariate analysis, tumor grade (P = 0.0006), bax status (P = 0.020), and EGFR status (P = 0.018) were significant and independent prognostic factors. DNA ploidy of the tumors was strongly associated with tumor grade. From January, 1994, to December, 1998, a series of 109 patients with ovarian carcinomas (FIGO IA-IIC) were treated with postoperative adjuvant chemotherapy. The same prognostic factors were studied in this series. The median follow-up was 48 months and the cancer-specific survival rate was 75%. Twenty-five (25%) tumor recurrences were recorded. The most favorable survival rate was seen in patients with tumors negative for p53 and positive for bcl-2 or bax. In a multivariate analysis, tumor grade (P = 0.014) and p53 status (P = 0.020) were independent prognostic factors. Clinical, histopathological and biological prognostic factors should be combined in prognostic models to render patient-tailored therapy possible and to define different prognostic groups for future clinical studies of adjuvant therapy in early stage ovarian carcinomas.

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