Factors influencing cellular radiosensitivity and survival curve analysis.
Notice bibliographique
Résumé
Investigating variance in radiosensitivity amongst cell populations contributes to the overall improvement in our understanding of the effects of low dose ionizing radiation. The aim of this thesis was to investigate factors influencing radiosensitivity through analysis of survival curves. The radiation-induced bystander effect and low dose hyperradiosensitivty were observed to help elucidate relationships between these phenomena. First heterogeneity of a cell population was investigated and seven clonal lines of an HCT 116 p53 wild type cell line were derived. Survival curves with a wide range of dose points (0.5 to 15 Gy) were developed and curves were fitted with the linear- quadratic and multi-target models. The McMaster Taylor Radiobiology Cesium-137 source was used for all irradiations in this thesis. Here it was evident that the multi- target model provided a better fit and further analysis revealed a relationship between the curve shoulder and toxicity of bystander effect signals. Clonal lines with a large shoulder size did not show evidence of the radiation induced bystander effect. Since the lowest dose point in curves was 0.5 Gy, a more focused look was taken in the low dose range. iii Survival curves were again produced for all clonal lines adding data to now include six dose points in the low dose region (below 0.5 Gy). Survival curves were re-analyzed with this extensive data set including doses from 0.01 to 15 Gy and now instances of hyperradiosensitivty were evident in all cell lines. The linear-quadratic model did not provide a meaningful fit to the data and so the induced-repair model was used and found to be appropriate in low doses. It was concluded that whether the radiation-induced bystander effect was produced or not, low dose effects such as hyperradiosensitivity may contribute to the overall radiosensitivity of a cell line. Finally, sex of the cell line was investigated using four cell lines. Of the four cell lines, two were included as controls for radiosensitivity. These two cell lines were null for the protein Artemis which assists in the repair of double strand DNA breaks. Thus, when this protein is not functioning as normal, radiosensitivity is induced in the cell line. Through medium transfer bystander effect assays a greater reduction in cell survival was observed in the normal female cell line compared to the normal male cell line. In conclusion, this thesis contributes to the understanding of low dose effects and non-targeted effects of ionizing radiation. Understanding these mechanisms both separately and in combination may contribute to the betterment of radiation therapies and radiation protection.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,003 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,006 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».