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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.
31

The effect of oxidative stress in lymphocytes from patients with inflammatory bowel disease and various cancer states compared with healthy control individuals

Najafzadeh, Mojgan January 2010 (has links)
In the present investigation peripheral blood lymphocytes from patients with inflammatory bowel disease (IBD) and different cancer states were treated with various agents and compared with lymphocytes from healthy control individuals (HCI) treated in the same way and measured in the Comet assay. For inflammatory bowel disease, patient's responses in IBD patients treated with H2O2 were higher than in HCI and Crohn's patients (CD) were found to have higher responses than Ulcerative colitis (UC) patients. The responses for all IBD and HCI were all reduced in the presence of chaga mushroom extract which behaved in an antioxidant manner. A second group of IBD patients were treated with the heterocyclic amine (food mutagen), IQ and H2O2 and responses were reduced in the presence of the flavonoids, quercetin and epicatechin and compared with HCI similarity treated. In all cells responses were reduced with flavonoids and again CD had higher responses than the UC patients and IBD patients higher than HCI. The responses with CD and UC were that confirmed in two independent studies with IBD, one with chaga mushroom extract and the other with flavonoids. Peripheral lymphocytes from malignant melanoma and suspected melanoma patients and colon cancer and polyposis patients were compared to the lymphocytes from HCI and treated with UVA. There were differential sensitivities when measured in the micronucleus and Comet assays. The cancer patients had higher responses than those in the precancerous states and they in turn were higher than responses in HCI. In all the studies, untreated baseline DNA damage values were also higher in IBD and cancer patients and pre-cancerous patients than HCIs. This would suggest that baseline frequencies of different diseases compared to controls could be an important biomarker in the diagnosis of pre-cancers and early stage cancers. Also peripheral lymphocytes are a useful surrogate for cancers and pre-cancerous disease states since, blood is present in all organs and tissues and DNA is basically the same in all cells.
32

Réparation par excision de nucléotides des dommages induits par rayons ultraviolets dans les mélanomes humains

Rajotte, Vincent 08 1900 (has links)
Les mélanomes malins (MM) constituent le deuxième type de cancer le plus fréquent chez les jeunes adultes canadiens (entre 20 et 44 ans) ainsi qu’un des rares cancers dont l’incidence augmente annuellement. À moins que les MM ne soient excisés à temps par chirurgie, les chances de survie des patients sont pratiquement nulles puisque ce type de tumeur est très réfractaire aux traitements conventionnels. Il est bien connu que l’exposition aux rayons ultraviolets (UV), induisant des photoproduits génotoxiques, est une déterminante majeure dans l’acquisition de MM. À cet effet, la réparation par excision de nucléotides (NER) est la ligne de défense principale contre le développement des mélanomes puisqu’elle est la voie de réparation prépondérante en ce qui a trait aux dits photoproduits. Malgré cela, la contribution potentielle de défauts de la NER au développement des MM dans la population normale n’est toujours pas bien établie. Notre laboratoire a précédemment développé une méthode basée sur la cytométrie de flux qui permet de mesurer la NER en fonction du cycle cellulaire. Cette méthode a déjà mise en évidence qu’une déficience de l’activité de la protéine ATR peut mener à une déficience de la NER exclusive à la phase S dans des fibroblastes humains. Pareillement, nous avons démontré que plusieurs lignées cellulaires cancéreuses modèles comportent une déficience en NER en phase S, suggérant qu’une telle déficience puisse caractériser certains types de cancers. Nous avons voulu savoir si une déficience en NER en phase S pouvait être associée à une proportion significative de mélanomes et si le tout pouvait être attribuable à une diminution de l’activité d’ATR. Nos objectifs ont donc été de : (i) mesurer l’efficacité de la NER en fonction du cycle cellulaire dans les MM en comparaison avec les mélanocytes primaires, (ii) vérifier si le niveau d’activité d’ATR corrèle avec l’efficacité de la NER en phase S dans les lignées de MM et (iii) voir si un gène fréquemment muté dans les mélanomes (tels PTEN et BRAF) pouvait coopérer avec ATR pour réguler la NER en phase S dans les mélanomes. Nous avons démontré que 13 lignées de MM sur 16 ont une capacité grandement diminuée à réparer les photoproduits induits par UV spécifiquement en phase S. De plus, cette déficience corrèle fortement avec une réduction de l’activation d’ATR et, dans plusieurs lignées de MM, avec une phosphorylation d’Akt plus importante. L’utilisation d’ARN interférent ou d’un inhibiteur du suppresseur de tumeurs PTEN, a permis, en plus d’augmenter la phosphorylation d’Akt, de réduire la réparation des photoproduits et l’activation d’ATR dans les cellules en phase S. En addition, (i) l’expression ectopique de la protéine PTEN sauvage dans des lignées déficientes en PTEN (mais pas d’une protéine PTEN sans activité phosphatase) ou (ii) l’inhibition pharmacologique d’Akt a permis d’augmenter la réparation en phase S ainsi que l’activation d’ATR. En somme, cette étude démontre qu’une signalisation d’ATR dépendante de PTEN/Akt amenant à une réparation déficiente des photoproduits génomiques causés par les UV en phase S peut être déterminante dans le développement des mélanomes induits par UV. / Malignant melanoma (MM) is the second most frequent neoplasia among young Canadian adults (aged 20-44); moreover the incidence of this disease continues to rise annually at an alarming rate. Unless primary melanoma is diagnosed early and promptly resected the patient prognosis is dismal since this deadly tumour type metastasizes extremely aggressively and is highly refractory to conventional treatment protocols. It is well established that exposure to UV light, and subsequent induction of genotoxic DNA photoproducts, is a primary determinant in the initiation of MM. Furthermore nucleotide excision repair (NER) clearly represents a critical frontline defence against MM because it is the only human pathway designed to remove the aforementioned DNA photoproducts. Despite this, the potential contribution of NER defects to sporadic MM development in the general population has remained unclear. Our laboratory previously developed a novel flow cytometry-based assay to evaluate the efficiency of NER as a function of cell cycle. This method was employed to demonstrate that functional ATR kinase is strictly required for NER during S phase in primary human fibroblasts. Intriguingly we also reported that many model tumour cell lines are deficient in NER uniquely in S phase populations, raising the possibility that such a defect might be characteristic of certain types of cancers. We therefore hypothesized that a significant proportion of human MM cell lines may exhibit reduced NER capacity specifically during S phase, and that this in turn might be attributeable to reduced ATR signaling. To test this hypothesis, three major specific aims were proposed: (i) To measure the efficiency of NER as a function of cell cycle among a panel of human MM cell lines and in primary melanocytes; (ii) To investigate whether any correlation exists between NER status and ATR activity during S phase in human MM cell lines; (iii) To investigate whether frequently mutated genes in melanoma (eg., PTEN, BRAF) might cooperate with ATR to regulate S phase-specific NER in MM cell lines. We were able to demonstrate that, in fact, 13/16 MM cell lines display remarkably diminished capacity to remove UV-induced DNA photoproducts specifically during S phase. Furthermore this defect correlates strongly with reduced activation of ATR kinase and, for a majority of MM, higher Akt phosphorylation levels. RNAi-mediated knockdown of the PTEN tumour suppressor, while stimulating Akt phosphorylation as expected, also engenders reductions in both photoproducts repair and ATR activation in S phase cells. In addition, (i) ectopic expression in PTEN-null strains of wild type PTEN but not of PTEN variants deficient in phosphatase activity, or (ii) pharmacological inhibition of Akt, significantly rescue S phase-specific repair as well as ATR activation. Our data indicate that reduced PTEN/Akt-dependent ATR signaling leading to defective repair of UV DNA photoproducts uniquely during S phase may represent an heretofore unrecognized major determinant in sunlight-induced melanoma development.
33

Etude des mécanismes moléculaires de résistance différentielle du mélanome malin aux vincalcaloïdes / Study of the molecular mechanisms of malignant melanoma differential resistance to vinca alkaloids

Attaoua, Chaker 19 June 2013 (has links)
Le mélanome malin (MM) est un cancer très réfractaire aux thérapies anticancéreuses, dont les vincalcaloïdes (VAs). Afin d'étudier le rôle de la GSTM1 (glutathion S-transférase 1) et la MRP1 (multidrug resistance protein 1) dans la résistance acquise du MM aux VAs, nous avons établi 4 modèles cellulaires de résistance à la vincristine (CAL1R-VCR), à la vindésine (CAL1R-VDS), à la vinorelbine (CAL1R-VRB) et à la vinflunine (CAL1R-VFL), par exposition continue de cellules du MM (CAL1-wt), pendant un an, à ces anticancéreux. L'expression d'ne GSTM1 fonctionnelle est spécifiquement observée (RT-PCR, western blot, activité GST totale) dans les cellules résistantes. Le curcumin (inhibiteur de GSTM1), la BSO (inhibiteur de synthèse de glutathion) et le MK571 (inhibiteur de MRP1), réduisent considérablement le résistance acquise à la VCR et à la VDS mais pas à la VRB ou à la VFL. Toutefois, tous ces VAs réduisent spécifiquement l'activité GSTM1. Ces données montrent l'implication différentielle de GSTM1 et MRP1 dans la résistance aux VAs. Pour déterminer les mécanismes moléculaires de cette chimiorésistance, nous avons réalisé une étude pangénomique (biopuces Affymetrix HG-U133 Plus 2.00) sur les lignées CAL1 (wt et R). Le regroupement hiérarchique (par Cluster et TreeView) des données des puces a révélé une similarité entre les profils d'expression génique de CAL1R-VRB et CAL1-wt mais aussi entre ceux de CAL1R-VCR et CAL1R-VDS. L'analyse bioinformatique (par IPA) des transcrits les plus différemment exprimés entre les lignées cellulaires, a mis en évidence 6 réseaux géniques connus pour leur rôle dans la chimiorésistance tumorale. Le programme FatiGO a révélé 3 termes biologiques sur-représentés (> 60%) dans CAL1R (ribosome, filaments intermédiaires du cytosquelette, récepteurs olfactifs) tandis que l'étude fonctionnelle (invalidation génique par siRNA, test de viabilité) de GPR143, KIT et SLC45A2 (gènes interagissant avec NF-κB et CCND1 (facteurs de la chimiorésistance tumorale), très exprimés dans CAL1-wt et muets dans CAL1R) a montré la faible tendance des deux premiers à être impliqués dans la résistance aux VAs. / Malignant melanoma (MM) is a very refractory tumor to anticancer therapies, including vinca alkaloïds (VAs). To investigate the role of GSTM1 (glutathione S-transferase μ1) and MRP1 (multidrug resistance protein 1) in MM acquired resistance to VAs, we established 4 cellular models of resistance to vincristine (CAL1R-VCR), to vindesine (CAL1R-VDS), to vinorelbine (CAL1R-VRB) and to vinflunine (CAL1R-VFL), by continuous exposure of MM cells (CAL1-wt), for one year, to these anticancer agents. The expression of a functional GSTM1 is specifically observed (RT-PCR, western blot, total GST activity) in resistant cells. Curcumin (GSTM1 inhibitor), BSO (glutathione synthesis inhibitor) and MK571 (MRP1 inhibitor), considerably reduce the acquired resistance to VCR and VDS but not that to VRB or VFL. However, all these VAs specifically reduce GSTM1 activity. These data show the differential involvement of GSTM1 and MRP1 in resistance to VAs. To determine the molecular mechanisms of this chemoresistance, we performed a pangenomic study (Affymetrix HG-U133 Plus 2.00 microarrays) on the CAL1 lines (wt and R). The hierarchical clustering (by Cluster and TreeView) of array data revealed a similarity between the gene expression profiles of CAL1R-VRB and CAL1-wt, but also between those of CAL1R-VCR and CAL1R-VDS. The bioinformatic analysis (by IPA) of the most differentially expressed transcripts between cell lines, highlighted 6 gene networks known for their role in tumor chemoresistance. FatiGO program revealed 3 biological terms overrepresented (>60%) in CAL1R (ribosome, intermediate filaments of cytoskeleton, olfactory receptors), while functional study (gene invalidation by siRNA, viability test) of GPR143, KIT and SLC45A2 (genes interacting with NF-kB and CCND1 (tumor chemoresistance factors), highly expressed in CAL1-wt and mute in CAL1R) showed the weak trend of the two formers to be involved in resistance to VAs.
34

Affinity assays for profiling disease-associated proteins in human plasma

Byström, Sanna January 2017 (has links)
Affinity-based proteomics offers opportunities for the discovery and validation of disease-associated proteins in human body fluids. This thesis describes the use of antibody-based immunoassays for multiplexed analysis of proteins in human plasma, serum and cerebrospinal fluid (CSF). This high-throughput method was applied with the objective to identify proteins associated to clinical variables. The main work in this thesis was conducted within the diseases of multiple sclerosis and malignant melanoma, as well as mammographic density, a risk factor for breast cancer. The suspension bead array (SBA) technology has been the main method for the work presented in this thesis (Paper I-IV). SBA assays and other affinity proteomic technologies were introduced for protein profiling of sample material obtained from clinical collaborators and biobanks. Perspectives on the validation of antibody selectivity by means of e.g. immuno-capture mass spectrometry are also provided. Paper I describes the development and application of a protocol for multiplexed pro- tein profiling of CSF. The analysis of 340 CSF samples from patients with multiple sclerosis and other neurological disease revealed proteins with potential association to disease progression (GAP43) and inflammation (SERPINA3). Paper II continued on this work with an extended investigation of more than 1,000 clinical samples and included both plasma and CSF collected from the same patients. Comparison of disease subtypes and controls revealed five plasma proteins of potential diagnostic relevance, such as IRF8 and GAP43. The previously reported associations for GAP43 and SERPINA3 in CSF was confirmed. Subsequent immunohistochemical analysis of post-mortem brain tissue revealed differential protein expression in disease affected areas. In Paper III, 150 serum samples from patients with cutaneous malignant melanoma were analyzed. Protein profiles from antibody bead arrays suggested three proteins (RGN, MTHFD1L, STX7) of differential abundance between patients with no disease recurrence and low tumor thickness (T-stage 1 and 2) compared to patients with high tumor thickness (T-stage 3 and 4) and disease recurrence. We observed MTHFD1L expression in tissue of a majority of patients, while expression of STX7 in melanoma tissue had been reported previously. Paper IV describes the analysis of protein in plasma in relation to mammographic breast density (MD), one of the strongest risk factors for the development of breast cancers. More than 1,300 women without prior history of breast cancer were screened. Linear associations to MD in two independent sample sets were found for 11 proteins, which are expressed in the breast and involved in tissue homeostasis, DNA repair, cancer development and/or progression in MD. In conclusion, this thesis describes the use of multiplexed antibody bead arrays for protein profiling of serum, plasma and CSF, and it shortlists disease associated proteins for further validation studies. / <p>QC 20170302</p>
35

Biomarker Discovery in Cutaneous Malignant Melanoma : A Study Based on Tissue Microarrays and Immunohistochemistry

Agnarsdóttir, Margrét January 2011 (has links)
The incidence of cutaneous malignant melanoma has increased dramatically in Caucasians the last few decades, an increase that is partly explained by altered sun exposure habits. For the individual patient, with a localized disease, the tumor thickness of the excised lesion is the most important prognostic factor. However, there is a need to identify characteristics that can place patients in certain risk groups. In this study, the protein expression of multiple proteins in malignant melanoma tumors was studied, with the aim of identifying potential new candidate biomarkers. Representative samples from melanoma tissues were assembled in a tissue microarray format and protein expression was detected using immunohistochemistry. Multiple cohorts were used and for a subset of proteins the expression was also analyzed in melanocytes in normal skin and in benign nevi. The immunohistochemical staining was evaluated manually and for part of the proteins also with an automated algorithm. The protein expression of STX7 was described for the first time in tumors of the melanocytic lineage. Stronger expression of STX7 and SOX10 was seen in superficial spreading melanomas compared with nodular malignant melanomas. An inverse relationship between STX7 expression and T-stage was seen and between SOX10 expression and T-stage and Ki-67, respectively. In a population-based cohort the expression of MITF was analyzed and found to be associated with prognosis. Twenty-one potential biomarkers were analyzed using bioinformatics tools and a protein signature was identified which had a prognostic value independent of T-stage. The protein driving this signature was RBM3, a protein not previously described in malignant melanoma. Other markers included in the signature were MITF, SOX10 and Ki-67. In conclusion, the protein expression of numerous potential biomarkers was extensively studied and a new prognostic protein panel was identified which can be of value for risk stratification.
36

Réparation par excision de nucléotides des dommages induits par rayons ultraviolets dans les mélanomes humains

Rajotte, Vincent 08 1900 (has links)
Les mélanomes malins (MM) constituent le deuxième type de cancer le plus fréquent chez les jeunes adultes canadiens (entre 20 et 44 ans) ainsi qu’un des rares cancers dont l’incidence augmente annuellement. À moins que les MM ne soient excisés à temps par chirurgie, les chances de survie des patients sont pratiquement nulles puisque ce type de tumeur est très réfractaire aux traitements conventionnels. Il est bien connu que l’exposition aux rayons ultraviolets (UV), induisant des photoproduits génotoxiques, est une déterminante majeure dans l’acquisition de MM. À cet effet, la réparation par excision de nucléotides (NER) est la ligne de défense principale contre le développement des mélanomes puisqu’elle est la voie de réparation prépondérante en ce qui a trait aux dits photoproduits. Malgré cela, la contribution potentielle de défauts de la NER au développement des MM dans la population normale n’est toujours pas bien établie. Notre laboratoire a précédemment développé une méthode basée sur la cytométrie de flux qui permet de mesurer la NER en fonction du cycle cellulaire. Cette méthode a déjà mise en évidence qu’une déficience de l’activité de la protéine ATR peut mener à une déficience de la NER exclusive à la phase S dans des fibroblastes humains. Pareillement, nous avons démontré que plusieurs lignées cellulaires cancéreuses modèles comportent une déficience en NER en phase S, suggérant qu’une telle déficience puisse caractériser certains types de cancers. Nous avons voulu savoir si une déficience en NER en phase S pouvait être associée à une proportion significative de mélanomes et si le tout pouvait être attribuable à une diminution de l’activité d’ATR. Nos objectifs ont donc été de : (i) mesurer l’efficacité de la NER en fonction du cycle cellulaire dans les MM en comparaison avec les mélanocytes primaires, (ii) vérifier si le niveau d’activité d’ATR corrèle avec l’efficacité de la NER en phase S dans les lignées de MM et (iii) voir si un gène fréquemment muté dans les mélanomes (tels PTEN et BRAF) pouvait coopérer avec ATR pour réguler la NER en phase S dans les mélanomes. Nous avons démontré que 13 lignées de MM sur 16 ont une capacité grandement diminuée à réparer les photoproduits induits par UV spécifiquement en phase S. De plus, cette déficience corrèle fortement avec une réduction de l’activation d’ATR et, dans plusieurs lignées de MM, avec une phosphorylation d’Akt plus importante. L’utilisation d’ARN interférent ou d’un inhibiteur du suppresseur de tumeurs PTEN, a permis, en plus d’augmenter la phosphorylation d’Akt, de réduire la réparation des photoproduits et l’activation d’ATR dans les cellules en phase S. En addition, (i) l’expression ectopique de la protéine PTEN sauvage dans des lignées déficientes en PTEN (mais pas d’une protéine PTEN sans activité phosphatase) ou (ii) l’inhibition pharmacologique d’Akt a permis d’augmenter la réparation en phase S ainsi que l’activation d’ATR. En somme, cette étude démontre qu’une signalisation d’ATR dépendante de PTEN/Akt amenant à une réparation déficiente des photoproduits génomiques causés par les UV en phase S peut être déterminante dans le développement des mélanomes induits par UV. / Malignant melanoma (MM) is the second most frequent neoplasia among young Canadian adults (aged 20-44); moreover the incidence of this disease continues to rise annually at an alarming rate. Unless primary melanoma is diagnosed early and promptly resected the patient prognosis is dismal since this deadly tumour type metastasizes extremely aggressively and is highly refractory to conventional treatment protocols. It is well established that exposure to UV light, and subsequent induction of genotoxic DNA photoproducts, is a primary determinant in the initiation of MM. Furthermore nucleotide excision repair (NER) clearly represents a critical frontline defence against MM because it is the only human pathway designed to remove the aforementioned DNA photoproducts. Despite this, the potential contribution of NER defects to sporadic MM development in the general population has remained unclear. Our laboratory previously developed a novel flow cytometry-based assay to evaluate the efficiency of NER as a function of cell cycle. This method was employed to demonstrate that functional ATR kinase is strictly required for NER during S phase in primary human fibroblasts. Intriguingly we also reported that many model tumour cell lines are deficient in NER uniquely in S phase populations, raising the possibility that such a defect might be characteristic of certain types of cancers. We therefore hypothesized that a significant proportion of human MM cell lines may exhibit reduced NER capacity specifically during S phase, and that this in turn might be attributeable to reduced ATR signaling. To test this hypothesis, three major specific aims were proposed: (i) To measure the efficiency of NER as a function of cell cycle among a panel of human MM cell lines and in primary melanocytes; (ii) To investigate whether any correlation exists between NER status and ATR activity during S phase in human MM cell lines; (iii) To investigate whether frequently mutated genes in melanoma (eg., PTEN, BRAF) might cooperate with ATR to regulate S phase-specific NER in MM cell lines. We were able to demonstrate that, in fact, 13/16 MM cell lines display remarkably diminished capacity to remove UV-induced DNA photoproducts specifically during S phase. Furthermore this defect correlates strongly with reduced activation of ATR kinase and, for a majority of MM, higher Akt phosphorylation levels. RNAi-mediated knockdown of the PTEN tumour suppressor, while stimulating Akt phosphorylation as expected, also engenders reductions in both photoproducts repair and ATR activation in S phase cells. In addition, (i) ectopic expression in PTEN-null strains of wild type PTEN but not of PTEN variants deficient in phosphatase activity, or (ii) pharmacological inhibition of Akt, significantly rescue S phase-specific repair as well as ATR activation. Our data indicate that reduced PTEN/Akt-dependent ATR signaling leading to defective repair of UV DNA photoproducts uniquely during S phase may represent an heretofore unrecognized major determinant in sunlight-induced melanoma development.
37

Patient and health care delays in malignant melanoma

Hajdarevic, Senada January 2012 (has links)
Background: Unlike other cancers, malignant melanoma (MM) is generally visible and can be easily and effectively cured if treated in time. Optimal cure of MM requires early detection, diagnosis, and treatment, which improves prognosis. However, patients as well as the health care organization and its professionals contribute to delayed treatment in various ways. Aims and objectives: The general aim of this PhD thesis was to explore reasons for delay in care seeking, diagnosis, and treatment of malignant melanoma. The specific objectives to be addressed were To explore patients’ decision making about seeking care for malignant melanoma To identify specific patterns in the decision-making process to seek care for suspect melanoma, as narrated by women and men To compare self-reported decision making coping styles between men and women in various ages, who live with or without a partner and are diagnosed with various stages of malignant melanoma in northern Sweden. To describe and compare patients diagnosed with MM, depending on their initial contact with care, and with regard to age, sex, and MM type and thickness, and to explore pathways and time intervals between clinics from the initial contact to diagnosis and treatment. Methods: In studies I and II, 21 and 30 patients, respectively, were interviewed about their decision making to seek care for MM. Study II focused on gender patterns in this decision making. The interviews were analysed using Grounded Theory (I) and qualitative content analysis (II). Study III included 270 people with MM who completed a translated questionnaire (Melbourne Decision Making Questionnaire) about coping styles in decision making. In study IV the pathways and time delay in health care for 71 people with MM were explored. Studies I and II were qualitative, whereas studies III and IV were quantitative. Results: In study I, the insights into severity and feelings of fear and existential threat were identified as key motivators for patients to decide to seek care for a suspected melanoma. Results in study II showed that gender constructions influenced the care-seeking behaviour. Women acknowledged the skin changes and attempted self-care first. They delayed care seeking due to family responsibilities. Men seldom acknowledged the suspicious skin change, but sought care immediately after prompting, and most often complied with relatives’ advice to seek care. Study III showed that men generally scored higher in buck-passing, while women and those living without a partner scored higher in hypervigilance. Participants with nodular melanoma (NM), a rapid-growing form of MM, scored higher in vigilance than those diagnosed as in situ melanoma. No correlation was found between tumour thickness and coping styles. Some differences concerning treatment of MM were found in study IV between people who initially had sought care at primary health care centres (PHC) and those who had sought care at dermatological and specialist clinics (Derm). Thicker tumours as well as NM were more common in the PHC group. A larger proportion of patients from PHCs were primarily excided within the primary health care; however, almost all of them were later referred to surgical clinics for wide excision. Patients within the PHC group also had to wait longer for the registered results of histopathological assessments. In general, women waited a shorter time for primary excision, and older people waited longer for wide excision. Conclusions: Time delay of diagnosis and treatment of MM is still common, and crucial to decrease. Future interventions should include gender aspects to influence people to seek care earlier. In health care, time delay could be decreased by facilitating access for patients with suspected skin melanomas, but also by reducing unnecessary referrals. Moreover, organizational changes whereby general practitioners and primary health care nurses are supported in using new technology for faster diagnoses and management of MM in collaboration with specialist clinics should be considered. Easy access and frequently used guidelines for MM could further decrease delay. Lastly, more efficient transfer and registration of laboratory results and referrals could decrease delay and improve patient safety. / Bakgrund: Malignt melanom (MM) är till skillnad från andra cancerformer ofta synlig och kan enkelt och kostnadseffektivt botas om det behandlas i tid. En optimal prognos av MM förutsätter tidig upptäckt, diagnos och behandling. Patienter, samt hälso- och sjukvården, dess organisation och dess personal kan på olika sätt bidra till fördröjning av behandlingen av MM. Syfte: Det övergripande syftet med denna avhandling var att undersöka orsaker till fördröjning att söka vård, diagnosticera och behandla malignt melanom. Specifika delsyften var:   Att utforska patienternas beslutsfattande process att söka vård för MM Att identifiera specifika mönster i beslutsfattande-processen att söka vård för misstänkt MM utifrån kvinnors och mäns egna berättelser  Att jämföra självrapporterade coping-stilar i den beslutsfattande processen mellan män och kvinnor i olika åldrar, boende med eller utan partner, och diagnosticerade med MM i olika stadier från norra Sverige Att beskriva och jämföra patienter med MM utifrån deras primära vårdkontakt samt utifrån ålder, kön, MM-typ och tjocklek. Ytterligare att utforska vård- och remissvägar samt tidsintervaller mellan olika kliniker från första kontakt till diagnos och behandling. Metod: I studie I och II, intervjuades 21 respektive 30 patienter om den beslutsfattande processen att söka vård för MM. Genuskonstruktioner i relation till den beslutsfattande processen var i fokus i studie II. Intervjuerna analyserades med hjälp av Grounded Theory (I) och kvalitativ innehållsanalys (II). I studie III inkluderades 270 patienter med MM som besvarade ett instrument (MDMQ) avseende coping-stilar i beslutsfattande processen. I studie IV undersöktes övergångar mellan olika kliniker och remissvägar för 71 patienter med MM samt eventuell tidsfördröjning inom hälso- och sjukvården. Resultat: I studie I, identifierades insikt i allvarlighetsgrad samt rädsla och existentiellt hot till följd av tillståndet vara nyckel-motivatorer för att bestämma sig för att söka vård för misstänkt hudmelanom. Resultat från studie II påvisade att genuskonstruktioner påverkar hur personer söker vård för MM. Kvinnor upptäckte själv sina melanom och försökte tillämpa egenvård i början. De kunde dröja att söka vård pga. ansvar för familjen. Män upptäckte sällan suspekta melanom själva men följde oftast anhörigas råd att söka vård och sökte vård omedelbart efter påstötning. Resultaten från studie III visade att män i högre grad använde en avvaktande startegi (buck-passing) medan kvinnor och de som bodde utan partner var överdrivet vaksamma (hypervigilance). Deltagare med nodulärt melanom (NM), en snabbt växande form av MM, var mer vaksamma (vigilance) jämfört med de med melanom in situ, en mycket tidig form av melanom. Några korrelationer mellan tumörtjocklek och coping-stilar hittades ej. Vissa skillnader avseende typer av MM samt vårdens handläggning beroende på var patienter initialt sökt vård identifierades i studie IV. Bland patienter som initialt sökt vård på hälsocentralerna var tjockare tumörer vanligare jämfört med dem som hade sökt vård på hud- och andra specialistklinker. Dessa patienter hade också som regel genomgått den primära excisionen på hälsocentralerna och en majoritet blev senare remitterade till kirurgisk klinik för utvidgad excision. Hälsocentralernas patienter fick vänta längre på att det histopatologiska svaret registrerades i journalen än sjukhusklinikernas patienter. Kvinnor fick generellt vänta kortare tid på primär excision och äldre patienter fick vänta längre för utvidgad excision. Slutsatser: Tidsfördröjning av diagnos och behandling av MM är fortfarande vanlig och därför viktig att minska. Framtida interventioner för att påverka människor att söka vård tidigare bör inkludera genusaspekter. Inom hälso- och sjukvården kan tidsfördröjning minskas genom förbättrad tillgänglighet för patienter med misstänkta hudmelanom, men också genom minskning av onödig remittering. En förändrad organisation där sjuksköterskor och primärvårdsläkare i samarbete med specialistkliniker stöttas att använda ny teknologi för snabbare diagnosticering och omhändertagande av MM bör övervägas. Ökad kännedom bland hälso- och sjukvårdspersonal om riktlinjer for MM-vård kan vidare minska fördröjning. Till sist, mer effektiva och förbättrade arbetssätt kring registrering och överföring av laboratoriska svar och remisser skulle kunna minska fördröjning och därmed öka patientsäkerheten.
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The effect of oxidative stress in lymphocytes from patients with inflammatory bowel disease and various cancer states compared with healthy control individuals.

Najafzadeh, Mojgan January 2010 (has links)
In the present investigation peripheral blood lymphocytes from patients with inflammatory bowel disease (IBD) and different cancer states were treated with various agents and compared with lymphocytes from healthy control individuals (HCI) treated in the same way and measured in the Comet assay. For inflammatory bowel disease, patient¿s responses in IBD patients treated with H2O2 were higher than in HCI and crohn¿s patients (CD) were found to have higher responses than Ulcerative colitis (UC) patients. The responses for all IBD and HCI were all reduced in the presence of chaga mushroom extract which behaved in an antioxidant manner. A second group of IBD patients were treated with the heterocyclic amine (food mutagen), IQ and H2O2 and responses were reduced in the presence of the flavonoids, quercetin and epicatechin and compared with HCI similarity treated. In all cells responses were reduced with flavonoids and again CD had higher responses than the UC patients and IBD patients higher than HCI. The responses with CD and UC were that confirmed in two independent studies with IBD, one with chaga mushroom extract and the other with flavonoids. Peripheral lymphocytes from malignant melanoma and suspected melanoma patients and colon cancer and polyposis patients were compared to the lymphocytes from HCI and treated with UVA. There were differential sensitivities when measured in the micronucleus and Comet assays. The cancer patients had higher responses than those in the precancerous states and they in turn were higher than responses in HCI. In all the studies, untreated baseline DNA damage values were also higher in IBD and cancer patients and pre-cancerous patients than HCIs. This would suggest that baseline frequencies of different diseases compared to controls could be an important biomarker in the diagnosis of pre-cancers and early stage cancers. Also peripheral lymphocytes are a useful surrogate for cancers and pre-cancerous disease states since, blood is present in all organs and tissues and DNA is basically the same in all cells.
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Características sociodemográficas y epidemiológicas de pacientes con cáncer de piel diagnosticados en un Hospital Nivel III-1 de región Lambayeque 2016-2019

Rufasto Ñañez, Claudia Estefany January 2024 (has links)
Objetivo: Identificar las características sociodemográficas y epidemiológicas del paciente con cáncer de piel diagnosticados en el servicio de anatomía patológica del Hospital Regional Lambayeque durante periodo enero del 2016 - diciembre del 2019. Métodos: La metodología empleada durante esta investigación estuvo basada en el diseño no experimental, descriptivo, de carácter retrospectivo, trasversal y observacional. Se incluyeron un total de 429 pacientes mayores de 18 años, diagnosticados con carcinoma cutáneo de tipo no melanoma (NPNM) y melanoma, mediante estudios anatomopatológicos de la lesión atendidos en Hospital Regional Lambayeque. La elección de la muestra fue mediante un muestreo no probabilístico de tipo censal, por la adaptabilidad al estudio. Resultados: De un total de 429 pacientes, 256(59,1%) tenían carcinoma basocelular (CBC), 146 (33,7%) carcinoma epidermoide (CsCC) y 31(7,2%) melanoma maligno cutáneo (MM). Siendo la edad promedio de aparición de 71 años en los NPNM y 62 años en el Melanoma Maligno Cutáneo, con predominio por el sexo femenino en el CBC y masculino en CsCC y MM. La ubicación anatómica más comprometida fue de la cabeza en los NPNM y miembros inferiores en MM, los cuales fueron identificadas mayormente por el servicio de Dermatología, seguido por Cirugía de Cabeza y Cuello del hospital. Los años con mayor número de carcinomas cutáneos fueron el 2019 para CBC y 2018 para los dos restantes. Conclusiones: La población general presenta más riesgo de presentar carcinomas no melanómico y en menor número el melanoma maligno, el cual predomina en áreas fotoexpuestas del cuerpo. / Objective: To identify the sociodemographic and epidemiological characteristics of the patient with skin cancer diagnosed in the pathological anatomy service of the Lambayeque Regional Hospital during the period January 2016 - December 2019. Methods: The methodology used during this investigation was based on the non-experimental design, descriptive, retrospective, cross-sectional and observational. A total of 429 patients over 18 years of age were included, diagnosed with non-melanoma skin carcinoma (NPNM) and melanoma, through anatomopathological studies of the lesion treated at Hospital Regional Lambayeque. The selection of the sample was by means of a non-probabilistic sampling of the census type, due to the adaptability to the study. Results: Of a total of 429 patients, 256 (59.1%) had basal cell carcinoma (BCC), 146 (33.7%) squamous cell carcinoma (SCC) and 31 (7.2%) cutaneous malignant melanoma (MM). Being the average age of appearance of 71 years in NPNM and 62 years in Cutaneous Malignant Melanoma, with a predominance of females in CBC and male in CsCC and MM. The most compromised anatomical location was the head in NPNM and lower limbs in MM, which were mostly identified by the Dermatology service, followed by Head and Neck Surgery at the hospital. The years with the highest number of skin carcinomas were 2019 for CBC and 2018 for the remaining two. Conclusions: The general population presents a higher risk of presenting non-melanoma carcinomas and a smaller number of malignant melanoma, which predominates in photo-exposed areas of the body.
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Le rôle d’Akt dans la réponse cellulaire aux dommages à l’ADN induits par les ultraviolets dans les cellules de mélanomes humains

Mansouri, Soukaina 09 1900 (has links)
Le mélanome malin est l’un des cancers les plus mortels dont l’incidence continue à augmenter chaque année avec peu de traitement efficace à long terme. Il est causé et initié principalement par l’exposition excessive aux rayons ultraviolets engendrant des photoproduits hautement génotoxiques. Il est bien connu que la cascade de signalisation PI3K/Akt joue un rôle crucial dans la régulation des processus qui sont généralement dérégulés durant le développement tumoral comme la prolifération, le contrôle du cycle cellulaire et l’apoptose. Néanmoins, l’implication de cette voie moléculaire dans la réponse aux dommages à l’ADN est peu caractérisée. Chez les mammifères, trois isoformes de la protéine kinase Akt ont été identifiées: Akt1, Akt2 et Akt3. Bien qu’elles soient très homologues en termes de séquence, plusieurs études ont montré que ces isoformes ont des fonctions biologiques distinctes, et nous suggérons qu’elles puissent contribuer différemment à la régulation de la réponse génotoxique. Les objectifs de ce projet étaient de: (i) évaluer l’activation d’Akt dans les cellules de mélanomes (ii) déterminer l’impact de l’inhibition de cette activité sur la régulation de la réponse cellulaire aux UV (iii) vérifier si la perte d’expression de l’un ou de l’autre des isoformes d’Akt peut réguler la réponse aux UV. Nous avons démontré qu’Akt est transitoirement hyperactivée par phosphorylation suite aux irradiations UV dans les lignées cellulaires de mélanomes. Afin de déterminer l'importance de cette activation dans la réponse cellulaire aux UV, notre approche était de diminuer (i) la phosphorylation d’Akt par l’usage d’inhibiteurs pharmacologiques ou (ii) l’expression de chaque isoforme d’Akt par l’approche des ARN interférents. Nous avons montré que l’inhibition de la phosphorylation d’Akt amène à l’augmentation du taux de l’apoptose induit par les UV d’une manière isoforme spécifique, alors qu’elle n’a aucun effet sur la régulation de la voie de réparation par excision de nucléotides (NER), qui est la seule voie humaine pour éliminer les dommages à l’ADN induits par les UV. En somme, notre étude constitue un nouvel aspect qui permet de mieux comprendre les mécanismes moléculaires du développement de mélanomes malins suites aux irradiations ultraviolettes. / Malignant melanoma is one of the deadliest cancers whose incidence continues to rise each year with a few effective long-term treatments. It is caused and initiated mainly by excessive exposure to ultraviolet radiation generating highly genotoxic DNA photoproducts. It is well known that the PI3K/Akt signaling cascade plays a crucial role in the regulation of processes commonly deregulated in tumor development such as proliferation, cell cycle control and apoptosis. Nevertheless, the nuclear involvement of this molecular pathway in the genotoxic response is poorly characterized. In mammals, three Akt kinase isoforms have been identified: Akt1, Akt2 and Akt3. Although these exhibit a high degree of homology, several studies have shown that they have distinct biological functions; therefore, we suggest that these isoforms may contribute differently to the regulation of genotoxic response. The objectives of this project were to: (i) evaluate Akt activation in UV-irradiated melanoma cells, (ii) determine the effect of the Akt phosphorylation inhibition on the regulation of the cellular response to UV, (iii) evaluate whether the loss of the expression of one or more of Akt isoforms can regulate the cellular response to UV. We demonstrated that Akt undergoes transient hyperactivation after UV treatment in melanoma cell lines. To determine the importance of this activation, our approach was to reduce (i) the phosphorylation of Akt by the use of pharmacological inhibitors or (ii) the expression of each individual Akt isoform using RNA interference. We have shown that inhibition of Akt phosphorylation leads to increased rates of UV-induced apoptosis in an isoform specific manner, while exerting no effect on regulation of nucleotide excision repair (NER), the only human pathway for eliminating UV-induced DNA damage. In summary, our study provides a better understanding of the molecular mechanisms of malignant melanoma development in response to UV.

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