9 documents found, page 1 of 1
Helicobacter pylori lipopolysaccharide structural domains and their recognition...
Silva, Lisete M.; Correia, Viviana G.; Moreira, Ana S.P.; Domingues, Maria Rosário M.; Ferreira, Rui M.; Figueiredo, Céu; Azevedo, Nuno F.The structural diversity of the lipopolysaccharides (LPSs) from Helicobacter pylori poses a challenge to establish accurate and strain-specific structure-function relationships in interactions with the host. Here, LPS structural domains from five clinical isolates were obtained and compared with the reference strain 26695. This was achieved combining information from structural analysis (GC-MS and ESI-MSn) with...
Helicobacter pylori activates matrix metalloproteinase 10 in gastric epithelial...
Costa, Angela M.; Ferreira, Rui M.; Pinto-Ribeiro, Inês; Sougleri, Ioanna S.; Oliveira, Maria J.; Carreto, Laura; Santos, Manuel A.Helicobacter pylori colonizes the human stomach and increases the risk for peptic ulcer disease and gastric carcinoma. H. pylori upregulates the expression and activity of several matrix metalloproteinases (MMPs) in cell lines and in the gastric mucosa. The aim of this study was to explore the mechanisms leading to upregulation of MMP10 in gastric epithelial cells induced by H. pylori Infection of gastric cells...
Validation of a fluorescence in situ hybridization method using peptide nucleic...
Cerqueira, L.; Fernandes, R. M.; Ferreira, Rui M.; Oleastro, Mónica; Carneiro, Fátima; Brandão, Catarina; Nunes, Pedro Pimentel; Ribeiro, Mário DinisHere, we evaluated a previously established peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) method as a new diagnostic test for Helicobacter pylori clarithromycin resistance detection in paraffin-embedded gastric biopsy specimens. Both a retrospective study and a prospective cohort study were conducted to evaluate the specificity and sensitivity of a PNA-FISH method to determine H. pylori cla...
Probe4pylori: a new kit for the rapid detection of H. pylori and associated cla...
Cerqueira, L.; Fernandes, R. M.; Ferreira, Rui M.; Oleastro, Mónica; Carneiro, Fátima; Brandão, Catarina; Nunes, Pedro Pimentel; Ribeiro, Mário DinisIn this study an evaluation of Probe4Pylori, a previously established PNA-FISH diagnostic test for H. pylori clarithromycin resistance in paraffin embedded gastric biopsies was performed and compared against culture followed by E-test and PCR. The Probe4Pylori showed very promising results with values of sensitivity (80%) and specificity (approximately 90%) for the patients harboring clarithromycin-resistant H....
Docosahexaenoic acid inhibits Helicobacter pylori growth in vitro and mice gast...
Correia, Marta; Michel, Valérie; Matos, António A.; Carvalho, Patrícia; Oliveira, Maria J.; Ferreira, Rui M.; Dillies, Marie-Agnès; Huerre, MichelH. pylori drug-resistant strains and non-compliance to therapy are the major causes of H. pylori eradication failure. For some bacterial species it has been demonstrated that fatty acids have a growth inhibitory effect. Our main aim was to assess the ability of docosahexaenoic acid (DHA) to inhibit H. pylori growth both in vitro and in a mouse model. The effectiveness of standard therapy (ST) in combination wit...
PNA-FISH as a new diagnostic method for the determination of clarithromycin res...
Fernandes, R. M.; Cerqueira, L.; Ferreira, Rui M.; Carneiro, Fátima; Ribeiro, Mário Dinis; Figueiredo, C.; Keevil, C. W.; Azevedo, N. F.; Vieira, M. J.Triple therapy is the gold standard treatment for Helicobacter pylori eradication from the human stomach, but increased resistance to clarithromycin became the main factor of treatment failure. Until now, fastidious culturing methods are generally the method of choice to assess resistance status. In this study, a new genotypic method to detect clarithromycin resistance in clinical samples, based on fluorescent ...
Application of fluorescence in situ hybridisation using peptide nucleic acid pr...
Cerqueira, L.; Fernandes, R. M.; Ferreira, Rui M.; Carneiro, F.; Ribeiro, M. Dinis; Figueiredo, C.; Azevedo, N. F.; Keevil, C. W.; Vieira, M. J.Microorganisms are responsible for several infectious diseases that can cause severe problems to patients and their treatment success is seriously correlated with the fast detection of the infectious agent. Some of the standard methods used, such as culturing methods are fastidious and time-consuming and do not give any information about the antibiotic resistance profile. Therefore, molecular methods have been ...
Helicobacter pylori colonization of the adenotonsillar tissue: fact or fiction?
Vilarinho, Sérgio; Guimarães, N.; Ferreira, Rui M.; Gomes, Bárbara; Wen, Xiaogang; Vieira, M. J.; Carneiro, Fátima; Godinho, Tiago; Figueiredo, C.Objective: The transmission of the gastric pathogen Helicobacter pylori involves the oral route. Molecular techniques have allowed the detection of H. pylori DNA in samples of the oral cavity, although culture of H. pylori from these type of samples has been sporadic. Studies have tried to demonstrate the presence of H. pylori in adenotonsillar tissue, with contradictory results. Our aim was to clarify whether ...
H. pylori colonization of the adenotonsillar tissue: fact or fiction?
Vilarinho, S.; Ferreira, Rui M.; Guimarães, N.; Gomes, B.; Xiaogang, W.; Oliveira, Fernando; Freitas, D.; Rodrigues, B.; Atraca, E.; Pereira, G.Gastric infection with Helicobacter pylori is the most common chronic infection worldwide. One of the routes of transmission of the infection is the oral route. Molecular techniques have allowed the detection of H. pylori DNA in samples of the oral cavity, although culture of H. pylori from these types of samples has been sporadic. Studies have tried to demonstrate the presence of H. pylori in adenotonsillar ti...