Metodi biochimici e biomolecolari applicati alla medicina clinica: rendimento della real-time TaqMan PCR per la valutazione della resistenza alla claritromicina in H.pylori e tests fecali nella diagnorstica del carcinoma colo-rettale: M2PK, calprotectina e FOBT

Saracino, Ilaria Maria (2011) Metodi biochimici e biomolecolari applicati alla medicina clinica: rendimento della real-time TaqMan PCR per la valutazione della resistenza alla claritromicina in H.pylori e tests fecali nella diagnorstica del carcinoma colo-rettale: M2PK, calprotectina e FOBT, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Biochimica, 23 Ciclo. DOI 10.6092/unibo/amsdottorato/3499.
Documenti full-text disponibili:
[img]
Anteprima
Documento PDF (Italiano) - Richiede un lettore di PDF come Xpdf o Adobe Acrobat Reader
Download (266kB) | Anteprima

Abstract

1) Background: The most common methods to evaluate clarithromycin resistance is the E-Test, but is time consuming. Resistance of Hp to clarithromycin is due to point mutations in the 23S rRNA. Eight different point mutations have been related to CH resistance, but the large majority of the clarithromycin resistance depends on three point mutations (A2142C, A2142G and A2143G). A novel PCR-based clarithromycin resistance assays, even on paraffin-embedded biopsy specimens, have been proposed. Aims: to assess clarithromycin resistance detecting these point mutation (E-Test as a reference method);secondly, to investigate relation with MIC values. Methods: Paraffin-embedded biopsies of patients Hp-positive were retrieved. The A2142C, A2142G and A2143G point mutations were detected by molecular analysis after DNA extraction by using a TaqMan real-time PCR. Results: The study enrolled 86 patients: 46 resistant and 40 sensible to CH. The Hp status was evaluated at endoscopy, by rapid urease test (RUT), histology and hp culture. According to real-time PCR, 37 specimens were susceptible to clarithromycin (wild type dna) whilst the remaining 49 specimens (57%) were resistant. A2143G is the most frequent mutation. A2142C always express a resistant phenotype and A2142G leads to a resitant phenotype only if homozigous. 2) Background: Colonoscopy work-load for endoscopy services is increasing due to colorectal cancer prevention. We tested a combination of faecal tests to improve accuracy and prioritize the access to colonoscopy. Methods: we tested a combination of fecal tests (FOBT, M2-PK and calprotectin) in a group of 280 patients requiring colonoscopy. Results: 47 patients had CRC and 85 had advanced adenoma/s at colonoscopy/histology. In case of single test, for CRC detection FOBT was the test with the highest specificity and PPV, M2-PK had the highest sensitivity and higher NPV. Combination was more interesting in term of PPV. And the best combination of tests was i-FOBT + M2-PK.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Saracino, Ilaria Maria
Supervisore
Dottorato di ricerca
Scuola di dottorato
Scienze biologiche, biomediche e biotecnologiche
Ciclo
23
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
helicobacter pylori cancro colo rettale
URN:NBN
DOI
10.6092/unibo/amsdottorato/3499
Data di discussione
7 Giugno 2011
URI

Altri metadati

Statistica sui download

Gestione del documento: Visualizza la tesi

^