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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.
61

Anticarcinogenic effects of genistein and anthocyanin extract in MCF-7 human breast cancer cells

Unknown Date (has links)
This study investigated potential apoptotic and anti-proliferative effects of the phytochemicals, genistein and anthocyanin extract, as single and combined treatments in MCF-7 human breast cancer cells. Cells were exposed to single and combined treatments with the phytochemiclas for 48 and 72 hours. Cell viability was assessed using the MTT bioassay. Apoptosis induction was assessed using acridine orange ethidium bromide and rhodamine 123 ethidium bromide fluorescence assays. Both singe and combination treatments induced dose- and time-dependent apoptotic cell death in MCF-7 cells. The percentage of apoptosis was higher in combination treatments than single treatments with either phytochemical, although the difference was not statistically significant. The combination of genistein and anthocyanin extract peaked in efficacy at 48 hours of treatment, to exhibit significantly greater (P<. O5) dose- and time-dependent cell cytotoxicity than single treatments. This study reveals potential chemopreventive implications for the complementary effects of genistein and anthocyanin extract. / by Corine M. Stinson. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
62

Influência da queima da palha de cana de açúcar na constituição do material particulado atmosférico (MP2,5 e MP10) e as suas implicações potenciais sobre a saúde humana /

Silva, Flavio Soares. January 2011 (has links)
Orientador: Mary Rosa Rodrigues de Marchi / Banca: Christine Laure Marie Bourote / Banca: Annibal Duarte Pereira Netto / Banca: Nilva Ré Poppi / Banca: Roma Tauler / Resumo: No Brasil, a queima da cana de açúcar é utilizada para facilitar a colheita, mas este procedimento causa grande poluição ambiental devido a quantidade de fuligem lançada na atmosfera. O material particulado (MP) emitido contém inúmeros contaminantes, tais como: hidrocarbonetos policíclicos aromáticos (HPAs) e elementos. A cidade de Araraquara/SP possui cerca de 200.000 habitantes e é cercada por plantações de cana de açúcar, sendo que a prática de queimada é constante no período da safra (abril-novembro, todos os anos). Neste trabalho, determinou-se a concentração elementar e de HPAs em MP na cidade de Araraquara durante o período da safra (S) e da entre safra (E) da cana de açúcar. Foram coletadas 60 amostras (E) e 220 amostras (S) para a análise de HPAs, e 10 amostras (E) e 10 amostras (S) para a análise elementar. As amostras foram coletadas utilizando um amostrador dicotômico (vazão: 10 L min-1, 24 h) com filtros de PTFE (37 mm, 2 μm de tamanho de poro). Para a análise de HPAs, dez filtros de PTFE contendo o MP foram extraídos em banho de ultrassom com acetona/n-hexano (1:1 v/v), sendo que as análises foram efetuadas por HPLC/FLD. A análise elementar foi efetuada por fluorescência de raios X por energia dispersiva (EDXRF), sem tratamento prévio das amostras. A concentração mediana de HPAs totais foi de 1,9 ng m-3 (E) e 6,2 ng m-3 (S). A concentração mediana de benzo[a]pireno, HPA considerado carcinogênico, foi de 0,026 ng m-3 e 0,15 ng m-3 para os períodos de E e S, respectivamente. O risco potencial de câncer associado à exposição a HPAs por inalação, foi estimado com base na concentração de benzo[a]pireno equivalente (BaPeq), onde a toxicidade de uma mistura de HPAs é definida pela concentração de cada substância multiplicada pelo seu fator de equivalência de toxicidade relativa (FET). Os valores medianos encontrados para... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Brazil, the sugar cane crops are burned to facilitate the harvesting, this procedure causes environmental pollution from the large amounts of soot that are released into the atmosphere. This particulate matter (MP) contains numerous contaminants such as polycyclic aromatic hydrocarbons (PAHs) and metals. The city of Araraquara, located at central area from São Paulo State, has around 200,000 inhabitants and is surrounded by sugarcane plantations (46,994 ha of total cultivated area, in the harvest 2008/2009). In this study, PAHs concentrations and elemental composition in the MP were determined in Araraquara city during the sugarcane harvesting (HV) and non-harvesting (NHV) seasons. 60 samples were collected during the NHV and 220 samples during the HV seasons for the analysis of PAHs. 10 samples were collected during the NHV and 10 samples during the HV season for the analysis of Si, K, Ca, Ti, V, Fe, Sr, Cr, Ni, Mn, Cu, Zn, As, Cd, Pb, Sb, Al, S and Cl. The samples were collected using a dichotomous sampler (10 L min-1, 24 h) with PTFE filters. Ten filters sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/FLD for the analysis of PAHs. Information concerning the bulk elemental concentration was provided by energy-dispersive x-ray fluorescence (EDXRF). The median concentration for total PAHs was 1.9 ng m-3 (NHV) and 6.2 ng m-3 (HV). Benzo[a]pyrene median concentration was 0.026 ng m-3 and 0.15 ng m-3 for the NHV and HV seasons, respectively. The potential cancer risk associated to inhalation exposure was estimated based on the benzo[a]pyrene toxic equivalence (BaPeq), where the overall toxicity of a PAH mixture is defined by the concentration of each compound multiplied... (Complete abstract click electronic access below) / Doutor
63

Identification de nouveaux gènes de prédisposition héréditaire au cancer du sein par génotypage tumoral et séquençage de nouvelle génération / Identification of new breast cancer susceptibility genes by tumor single nucleotide polymorphism array and next generation sequencing

Bubien, Virginie 12 December 2016 (has links)
5 à 10% des cancers du sein sont héréditaires mais parmi ceux-ci seulement la moitié est expliquée par une altération constitutionnelle d’un gène de prédisposition connu tels que les gènes BRCA1 et BRCA2. L’importante hétérogénéité génétique qui caractérise les famillesBRCAx rend difficile la réalisation d’études familiales groupées et ne permet pas l’identification de nouveaux gènes de prédisposition au cancer du sein selon les méthodes classiques de liaison génétique ou d’association. Les techniques de séquençage de nouvelle génération (NGS) à l’échelle de l’exome ou du génome entier, autorisent en revanche l’étude de familles individuelles à la recherche de mutations constitutionnelles privées mais le nombre considérable de variants génétiques identifiés impose leur tri sur des critères de pathogénicité ou de récurrence. Un autre critère de tri peut être représenté par l’identification de régions candidates définies en fonction de réarrangements génomiques tumoraux communs à plusieurs tumeurs au sein d’une même famille. Le génotypage tumoral par puces SNP (pour single nucleotide polymorphism) permet en effet la détection d’haplotypes conservés dans des régions récurrentes de LOH (pour loss of heterozygosity) communes à plusieurs tumeurs familiales et donc l’identification de régions candidates suspectes d’abriter des mutations germinales dans des gènes de prédisposition au cancer. La combinaison de ces deux approches, génotypage tumoral puis NGS, a été appliquée à une série de 17 familles avec agrégation de cancers du sein pour lesquelles au moins deux échantillons tumoraux étaient disponibles. Aucun nouveau gène de prédisposition au cancer du sein n’a été identifié mais une mutation délétère constitutionnelle du gène ATM a ainsi été retrouvée, associée à une perte de l’allèle sauvage dans les 2 tumeurs d’une famille BRCAx. L’analyse de 17 tumeurs du sein supplémentaires provenant de 10 familles avec agrégation de cancers du sein et mutation constitutionnelle du gène ATM identifiée chez le cas index, a révélé que l’allèle sauvage d’ATM était fréquemment perdu dans ces tumeurs (>80% contre 20% attendu en situation sporadique ; p<0.001). Ce résultat plaide fortement en faveur de l’implication d’ATM dans la carcinogénèse de ces cancers du sein tel un gène suppresseur de tumeur et suggère que les mutations constitutionnelles d’ATM sont impliquées dans des formes familiales de cancer du sein. / Hereditary breast cancers (BCs) account for 5-10% of all diagnosed BCs, yet only 50% of such tumors arise in the context of a germline mutation in known tumor suppressor genes such as BRCA1 or BRCA2. The vast genetic heterogeneity which characterizes BRCAx families makes grouped studies impossible to perform. Next generation sequencing (NGS) techniques, however, allow individual families to be studied in order to identify private mutations. Single nucleotide polymorphism (SNP) arrays allow the detection of conserved haplotypes within recurrent regions of loss of heterozygosity, common to several familial tumors, therefore identifying genomic loci likely to harbor a germline mutation in cancer predisposition genes. The combination of both exome sequencing and SNP arrays for a series of 17 familial BC did not allow the identification of a novel BC predisposition gene, but revealed a germline ATM mutation associated with a loss of the wild-type allele in a BRCAx family. The analysis of 17 additional breast tumors from ten BC families in which a germline ATM mutation had been identified revealed a high frequency of wild-type allele loss in these tumors (>80% compared to the 20% expected in sporadic BC; p <0.001). This result argues strongly in favor of the involvement of ATM in the carcinogenesis of these tumors as a tumor suppressor gene and suggests that germline ATM mutations are involved in a subset of familial BC.
64

Type 2 diabetes mellitus and medications for type 2 diabetes mellitus are associated with risk for and mortality from cancer in a German primary care cohort

Baur, Dorothee M., Klotsche, Jens, Hamnvik, Ole-Petter R., Sievers, Caroline, Pieper, Lars, Wittchen, Hans-Ulrich, Stalla, Günter K., Schmid, Roland M., Kales, Stefanos N., Mantzoros, Christos S. January 2011 (has links)
There is growing evidence that patients with type 2 diabetes mellitus have increased cancer risk. We examined the association between diabetes, cancer, and cancer-related mortality and hypothesized that insulin sensitizers lower cancer-related mortality. Participants in the Diabetes Cardiovascular Risk and Evaluation: Targets and Essential Data for Commitment of Treatment study, a nationwide cross-sectional and prospective epidemiological study, were recruited from German primary care practices. In the cross-sectional study, subjects with type 2 diabetes mellitus had a higher prevalence of malignancies (66/1308, 5.1%) compared to nondiabetic subjects (185/6211, 3.0%) (odds ratio, 1.64; 95% confidence interval, 1.12-2.41) before and after adjustment for age, sex, hemoglobin A1c, smoking status, and body mass index. Patients on metformin had a lower prevalence of malignancies, comparable with that among nondiabetic patients, whereas those on any other oral combination treatment had a 2-fold higher risk for malignancies even after adjusting for possible confounders; inclusion of metformin in these regimens decreased the prevalence of malignancies. In the prospective analyses, diabetic patients in general and diabetic patients treated with insulin (either as monotherapy or in combination with other treatments) had a 2- and 4-fold, respectively, higher mortality rate than nondiabetic patients, even after adjustment for potential confounders (incidence of cancer deaths in patients with type 2 diabetes mellitus [2.6%] vs the incidence of cancer deaths in patients without type 2 diabetes mellitus [1.2%]). Our results suggest that diabetes and medications for diabetes, with the exception of the insulin sensitizer metformin, increase cancer risk and mortality.
65

Exposure to Phthalates during Critical Windows of Susceptibility and Breast Tissue Composition: Implications for Breast Cancer Risk

Oskar, Sabine January 2021 (has links)
Secular trends in breast cancer incidence in younger women suggest environmental factors, like exposure to environmental chemicals, may play a role in rising incidence. One of the strongest risk factors for developing breast cancer, next to family history, is high mammographic breast density, which is defined as the proportion of fibroglandular breast tissue relative to fat as seen on a mammogram. Phthalates, a ubiquitous endocrine disrupting chemical, have the potential to interfere with endogenous hormones like estrogen and androgens. There is growing evidence from animal and epidemiologic studies indicating distinct periods of heightened susceptibility to endocrine disrupting chemicals throughout the life course, particularly during critical windows of breast development. Exposure to hormonally active environmental chemicals like phthalates may be a modifiable risk factor for breast cancer, therefore reducing or eliminating exposure could have substantial public health benefits. The overarching goal of this dissertation was to assess the relationship between exposure to phthalates during two critical windows of susceptibility, the prenatal and pregnancy periods, and its effect on breast tissue composition in adolescence and adulthood. First, a comprehensive review of epidemiologic studies summarized the body of evidence for the association between phthalate exposure and intermediate markers known to be in the causal pathway of breast cancer risk (age at breast development, menarche, and breast tissue composition). This systematic review of the literature aimed to identify potential patterns of evidence by outcome and timing of exposure. Evidence from this review suggested that phthalate exposure during the prenatal and childhood periods may play a role in altering menarche. Findings for phthalate exposure and age at breast development were inconclusive. There was a considerable lack of epidemiologic data on phthalate exposure and breast tissue composition throughout the life course. Based on one study, there is a potential association between phthalate exposure during pre-puberty and altered breast tissue density in adolescent girls. No study assessed the relationship between phthalate exposure during the prenatal or pregnancy period and subsequent breast tissue composition. Second, an examination for the association between prenatal phthalate exposure and breast tissue composition measured in adolescence (Chapter 3) and the association between phthalate exposure during pregnancy and breast tissue composition measured during or after the postpartum transient period (Chapter 4) aimed to address this major gap identified from the comprehensive review. The empirical chapters of this dissertation used data from an ongoing longitudinal birth cohort study of mothers and their children conducted by the New York City Columbia Center for Children's Environmental Health and the Breast Cancer and the Environment Research Project (CCCEH-BCERP). The CCCEH-BCERP study cohort has prospective data on nine phthalate metabolite concentrations measured during the third trimester of pregnancy and breast tissue composition measured in a subsample of mother-daughter dyads. Notably, we used novel non-invasive methods (optical breast spectroscopy) in this younger cohort of mothers and daughters to objectively measure specific components of the bulk breast composition before mammography screening age. There was significant evidence of altered breast tissue composition in both mothers and daughters. For daughters (n=127, mean age 15.2 ± 1.9 years), prenatal exposures to select low molecular weight (LMW) and high molecular weight (HMW) phthalate metabolites altered overall breast density in opposing directions, which appears to be driven by significant altered percent breast water. There was a significant association between higher prenatal levels of a LMW phthalate metabolite (monobutyl phthalate) and lower levels of overall breast density (adjusted β = -0.32; 95% CI: -0.51, -0.13) and significant association between sum of di(2-ethylhexyl) phthalate (∑DEHP), a HMW phthalate metabolite, and higher levels of overall breast density in girls (adjusted β = 0.20; 95% CI: 0.05, 0.34). For mothers (n=133, mean age 41 ± 5.3 years at follow-up), there was a significant association between two LMW phthalate metabolites and lower levels of percent breast collagen. Additionally, there was a significant inverse relationship between levels of mono-(3-carboxypropyl), a HMW phthalate metabolite, and percent total hemoglobin of the breast (adjusted β =-0.03; 95% CI: -0.06, 0.00, p=0.05). Overall, this dissertation increased our understanding of the impact that exposure to phthalates during critical windows of susceptibility may have on specific components of the breast. Reducing exposure to both HMW and LMW phthalates may have an impact in reducing breast cancer risk, particularly for girls prenatally exposed, as there was stronger evidence of higher overall breast density and percent water from exposure to select HMW phthalates. Future prospective studies should confirm these results as findings might provide an opportunity for modifying potential breast cancer risk.
66

Breast Cancer Risk Localization in Mammography Images using Deep Learning

Rystedt, Beata January 2020 (has links)
Breast cancer is the most common form of cancer among women, with around 9000 new diagnoses in Sweden yearly. Detecting and localizing risk of breast cancer could give the opportunity for individualized examination programs and preventative measures if necessary, and potentially be lifesaving. In this study, two deep learning methods have been designed, trained and evaluated on mammograms from healthy patients whom were later diagnosed with breast cancer, to examine how well deep learning models can localize suspicious areas in mammograms. The first proposed model is a ResNet-18 regression model which predicts the pixel coordinates of the annotated target pixel in the prior mammograms. The regression model produces predictions with an average of 44.25mm between the predictions and targets on the test set, which for average sized breasts correspond to a general area of the breast, and not a specific location. The regression network is hence not able to accurately localize suspicious areas in mammograms. The second model is a U-net segmentation model that segments out a risk area in the mammograms. The segmentation model had a 25% IoU, meaning that there is on average a 25% overlap between the target area and the prediction area. 57% of the predictions of the segmentation network had some overlap with the target mask, and predictions that did not overlap with the target often marked high density areas that are traditionally associated with high risk. Overall, the segmentation model did better than the regression model, but needs further improvement before it can be considered adequate to merge with a risk value model and used in practice. However, it is evident that there is sufficient information present in many of the mammogram images to localize the risk, and the research area holds potential for future improvements. / Bröstcancer är den vanligaste cancerformen bland kvinnor, med cirka 9000 nya diagnoser i Sverige årligen. Att upptäcka och lokalisera risken för bröstcancer kan möjliggöra individualiserade undersökningsprogram och förebyggande åtgärder vid behov och kan vara livräddande. I denna studie har två djupinlärningsmodeller designats, tränats och utvärderats på mammogram från friska patienter som senare diagnostiserades med bröstcancer, för att undersöka hur väl djupinlärningsmodeller kan lokalisera misstänkta områden i mammogram. Den första föreslagna modellen är en ResNet-baserad regressionsmodell som förutsäger pixelkoordinaterna för den utmarkerade målpixeln i de friska mammogrammen. Regressionsmodellen producerar förutsägelser med ett genomsnitt på 44,25 mm mellan förutsägelserna och målpunkterna för testbilderna, vilket för medelstora bröst motsvarar ett allmänt bröstområde och inte en specifik plats i bröstet. Regressionsnätverket kan därför inte med precision lokalisera misstänkta områden i mammogram. Den andra modellen är en U-net segmenteringsmodell som segmenterar ut ett riskområde ur mammogrammen. Segmenteringsmodellen hade ett IoU på 25%, vilket innebär att det i genomsnitt fanns en 25-procentig överlappning mellan målområdet och förutsägelsen. 57% av förutsägelserna från segmenteringsnätverket hade viss överlappning med målområdet, och förutsägelser som inte överlappade med målet markerade ofta områden med hög täthet som traditionellt är förknippade med hög risk. Sammantaget presterade segmenteringsmodellen bättre än regressionsmodellen, men behöver ytterligare förbättring innan den kan anses vara adekvat nog att sammanfogas med en riskvärdesmodell och användas i praktiken. Det är dock uppenbart att det finns tillräcklig information i många av mammogrambilderna för att lokalisera risken, och att forskningsområdet har potential för framtida förbättringar.
67

The Acute-Phase Response and Cancer Risk

Sivak-Sears, Niccole R. 06 August 2003 (has links)
No description available.
68

Utilizing Cancer Resistant and Susceptible Mice to Identify the Genetic Contributions to Cutaneous Squamous Cell Carcinoma Susceptibility

Fleming, Jessica L. 18 December 2012 (has links)
No description available.
69

The American Suntanning Association: A “Science-First Organization” With a Biased Scientific Agenda

Stapleton, Jerod L., Coups, Elliot J., Hillhouse, Joel J. 01 May 2013 (has links)
No description available.
70

Hepatitis B and C associated cancer and mortality: New South Wales, 1990-2002.

Amin, Janaki, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2006 (has links)
This thesis examines cancer and mortality rates among people diagnosed with hepatitis B (HBV) and C (HCV) infection in New South Wales (NSW) from 1990 through 2002, by linking hepatitis notifications with the NSW Central Cancer Registry (CCR) and National Death Index. Of the 39101 HBV, 75834 HCV and 2604 HBV/HCV co-infection notifications included 1052, 1761 and 85 were linked to cancer notifications and 1233, 4008 and 186 were linked to death notifications respectively. Of 2072 hepatocellular carcinoma (HCC) notifications to the CCR 323, 267 and 85 were linked to HBV, HCV and HBV/HCV co-infection notifications. Incidence of HCC was 6.5, 4.0 and 5.9 per 1000 person years for HBV, HCV and HBV/HCV co-infected groups. Risk of HCC in those diagnosed with hepatitis was 20 to 30 times greater than the standard population. There was a marginally statistically significant increased risk of immunoproliferative malignancies associated with HCV infection (SIR=5.6 95% CI 1.8 ???17.5). Risk of death for those with hepatitis was significantly greater, 1.5 to 5 fold, than the general population with the greatest risk among those with HBV/HCV co-infection. The primary cause of HBV deaths was liver related, particularly HCC, whereas in the HCV groups drug related deaths were most frequent. Among people with HCV, risk of dying from drug related causes was significantly greater than from liver related causes (p=0.012), with the greatest increased risk in females age 15- 24 years (SMR 56.9, 95%CI 39.2???79.9). Median age at diagnosis of HCC varied markedly by country of birth and hepatitis group: HBV 66, 63 and 57years ; HCV 51, 68 and 71 years; unlinked 69, 70 and 64 years for Australian, European, and Asian-born groups, respectively (P<0.0001 for all groups). While the risk of cancer, particularly HCC, is elevated among people with HBV and HCV infection, the absolute risk remains low. Young people with HCV face a higher mortality risk from continued drug use than from liver damage related to their HCV infection. The influence of IDU in the epidemiology of HCC in New South Wales was possibly reflected in the varying distributions of age and country of birth.

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