Cancer biomarker discovery using selected ion flow tube mass spectrometry
Notice bibliographique
Résumé
Lung cancer is one of the most common types of neoplasm and is a leading cause of death in Canada. Accurate early diagnosis is key to the effective treatment of the disease, however the current means to do so, such as Computed Tomography diagnostic imaging, are costly, invasive, and not practical for routine use. The detection of volatile cancer biomarkers in breath represents an attractive non-invasive means to diagnose the disease. It is unclear, however, which, if any, breath chemicals have diagnostic utility. In this thesis I used Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), a trace gas analytic method to (a) identify potential volatile cancer biomarkers in blood, and (b) investigate whether these markers are present in breath. Potential biomarkers were identified by comparing products ions formed in the reaction between hydronium (H3O+) and nitronium (NO+) precursor ions and trace gases present in the headspace of plasma obtained from patients with breast cancer, colorectal or lung cancer, and healthy controls. Using this approach product ions of interest were identified which derive from a wide range of chemical classes including aldehydes, acids, alcohols and sulphides, including some which have been identified previously by other investigators. Many of these ions could be quantified in the breath of healthy controls and therefore be suitable for quantification by breath analysis. The production rate of most of these ions was, however, poorly correlated between those formed in the reactions between nasal breath and those formed in reactions with blood headspace, even when using in samples collected and analysed simultaneously from the same participants. The lack of correlation suggests that the breath trace gases from which these product ions are formed are not dependent on the blood concentration of the same gas, but likely derive mainly from the airways. As such while my data suggest that cancer biomarkers may be found in the bloodstream, breath analysis is not a suitable means to non-invasively detect these cancer markers, in particular cancers of tissues other than those found in the airway. On the other hand, my data suggests that the detection of airway disease, including that of lung cancer, may be suitable candidates for the diagnosis and/or screening using breath analysis.
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) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 ».