The main cause of failure of Helicobacter pylori eradication therapy is resistance to clarithromycin. The resistance is due to three point mutations in two positions on the 23S rRNA (A2142C, A2142G, and A2143G). Our aim was to develop a rapid and accurate method to detect these mutations directly on biopsy specimens. We developed a real-time PCR that included a simultaneous detection of the amplicons by hybridization of two probes labeled with LC-Red and fluorescein by using the fluorescence resonance energy transfer (FRET) technology and melting curve analysis with the LightCycler thermocycler. The assay was first applied successfully on reference strains, reference plasmids, and H. pylori -negative biopsies. Biopsies from 200 patients having failed a first eradication attempt and for whom the H. pylori strain was available were then tested with the new assay. A result was obtained in 199 cases; a single genotype was detected in 157 cases, two genotypes were detected in 41 cases, and three genotypes were detected in one case. There were, in total, seven discrepancies between the real-time PCR and the phenotypic method of determination of clarithromycin susceptibility, and in an additional four cases the two phenotypic methods were in disagreement. PCR-restriction fragment length polymorphism was applied to a sampling of biopsies, including all of the cases with multiple genotypes and all the cases with discrepant results. Finally, in four cases with discrepant results, the real-time PCR detected the resistant population at a concentration so low that it could not be detected by the phenotypic method, while in three cases other mutations could be involved. This assay had an accuracy at least as satisfactory as that of the phenotypic tests and could be performed within 2 h, allowing it to be used before the administration of therapy in the case of a first H. pylori eradication.

Amphiphilic molecules based on nucleosides, nucleotides and oligonucleotides are finding more and more biotechnological applications. This Perspective highlights their synthesis, supramolecular organization as well as their applications in the field of biotechnology.

Background: Few studies have specifically addressed the management of the symptoms of gastro‐oesophageal reflux disease, and there are no comparative data in this respect for acid pump inhibitors and prokinetic agents. Methods: Following endoscopy 424 patients presenting with heartburn as the predominant symptom of gastro‐oesophageal reflux disease were randomized to treatment with omeprazole 20 or 10 mg once daily, or cisapride 10 mg four times daily, in a double‐blind, double‐dummy, parallel group, multicentre study. Symptoms and quality of life were assessed at 4 weeks. Patients still experiencing heartburn continued therapy for a further 4 weeks and the assessments were repeated. Results: At 4 weeks, heartburn was resolved in 65% (95% CI: 57–73%), 56% (48–64%) and 41% (32%–49%) of patients treated, respectively, with omeprazole 20 mg and 10 mg once daily, and cisapride. Both omeprazole doses were significantly more effective than cisapride (P < 0.01). The same order of efficacy was observed regardless of the presence of erosive oesophagitis. Regurgitation and epigastric pain also improved to a greater degree with omeprazole than with cisapride. Quality of life was improved in all treatment groups, and the improvement in the reflux dimension of the Gastrointestinal Symptom Rating Scale (GSRS) score was significantly different between groups (P = 0.002). Conclusions: Omeprazole 20 or 10 mg once daily is significantly more effective than cisapride in the resolution of heartburn, regardless of the presence of erosive oesophagitis, and this is accompanied by an improvement in patient quality of life.

Hybrid lipid oligonucleotide conjugates are finding more and more biotechnological applications. This short critical review highlights their synthesis, supramolecular organization as well as their applications in the field of biotechnology (111 references).