Crop wild relative populations of Beta vulgaris allow direct mapping of agronomically important genes.

Rapid identification of agronomically important genes is of pivotal interest for crop breeding. One source of such genes are crop wild relative (CWR) populations. Here we used a CWR population of <200 wild beets (B. vulgaris ssp. maritima), sampled in their natural habitat, to identify the sugar beet (Beta vulgaris ssp. vulgaris) resistance gene Rz2 with a modified version of mapping-by-sequencing (MBS). For that, we generated a draft genome sequence of the wild beet. Our results show the importance of preserving CWR in situ and demonstrate the great potential of CWR for rapid discovery of causal genes relevant for crop improvement. The candidate gene for Rz2 was identified by MBS and subsequently corroborated via RNA interference (RNAi). Rz2 encodes a CC-NB-LRR protein. Access to the DNA sequence of Rz2 opens the path to improvement of resistance towards rhizomania not only by marker-assisted breeding but also by genome editing.

Noncontact laser microdissection and catapulting for pure sample capture.

The understanding of the molecular mechanisms of cellular function, growth, and proliferation is based on the accurate identification, isolation, and finally characterization of a specific single cell or a population of cells and its subsets of biomolecules. For the simultaneous analysis of thousands of molecular parameters within one single experiment as realized by DNA, RNA, and protein microarray technologies, a defined number of homogeneous cells derived from a distinct morphological origin are required. Sample preparation is therefore a very crucial step preceding the functional characterization of specific cell populations. Laser microdissection and laser pressure catapulting (LMPC) enables pure and homogeneous sample preparation resulting in an increased specificity of molecular analyses. With LMPC, the force of focused laser light is utilized to excise selected cells or large tissue areas from object slides down to individual single cells and subcellular components like organelles or chromosomes. After microdissection, the sample is directly catapulted into an appropriate collection vial. As this process works entirely without mechanical contact, it enables pure sample retrieval from morphologically defined origin without cross-contamination. LMPC has been successfully applied to isolate and catapult cells from, for example, histological tissue sections, from forensic evidence material, and also from tough plant matter, supporting biomedical research, forensic science, and plant physiology studies. Even delicate living cells like stem cells have been captured for recultivation without affecting their viability or stem cell character, an important feature influencing stem cell research, regenerative medicine, and drug development. The combination of LMPC with microinjection to inject drugs or genetic material into individual cells and to capture them for molecular analyses bears great potential for efficient patient-tailored medication.

Esomeprazole 20 mg vs. pantoprazole 20 mg for maintenance therapy of healed erosive oesophagitis: results from the EXPO study.

BACKGROUND: Following initial healing of erosive oesophagitis, most patients require maintenance therapy to prevent relapse. AIM: To compare endoscopic and symptomatic remission rates over 6 months' maintenance therapy with esomeprazole or pantoprazole (both 20 mg once daily) in patients with healed erosive oesophagitis. METHODS: Patients with symptoms of gastro-oesophageal reflux disease and endoscopically confirmed erosive oesophagitis at baseline were randomized to receive esomeprazole 40 mg or pantoprazole 40 mg for up to 8 weeks. Patients with healed erosive oesophagitis and free of moderate/severe heartburn and acid regurgitation at 4 weeks or, if necessary, 8 weeks entered the 6-month maintenance therapy phase of the study. RESULTS: A total of 2766 patients (63% men; mean age 50 years) received esomeprazole 20 mg (n = 1377) or pantoprazole 20 mg (n = 1389) and comprised the intention-to-treat population. Following 6 months of treatment, the proportion of patients in endoscopic and symptomatic remission was significantly greater for those receiving esomeprazole 20 mg (87.0%) than pantoprazole 20 mg (74.9%, log-rank test P < 0.0001). Esomeprazole 20 mg produced a higher proportion of patients free of moderate to severe gastro-oesophageal reflux disease symptoms and fewer discontinuations because of symptoms than pantoprazole 20 mg (92.2% vs. 88.5%, P < 0.001). CONCLUSIONS: Esomeprazole 20 mg is more effective than pantoprazole 20 mg for maintenance therapy following initial healing of erosive oesophagitis and relief of gastro-oesophageal reflux disease symptoms.

On-demand therapy with pantoprazole 20 mg as effective long-term management of reflux disease in patients with mild GERD: the ORION trial.

AIMS: To compare safety and efficacy of on-demand pantoprazole 20 mg/40 mg versus placebo in the long-term management of patients with mild gastroesophageal reflux disease (GERD) after heartburn relief. METHODS: A total of 634 patients with endoscopically confirmed GERD grade 0/I and heartburn were included. During the acute phase, patients were treated with pantoprazole 20 mg once daily for 4 weeks. Those patients relieved from heartburn entered the long-term phase, and were randomly assigned to either treatment group pantoprazole 20 mg, 40 mg or placebo. Over 6 months, patients took study medication on demand (antacids as rescue medication) and discontinued the drug once symptoms abated. RESULTS: After 4 weeks a total of 87.1%/90.0% of patients were free of heartburn (ITT/PP), and entered the subsequent long-term phase. The perceived average daily symptom load (placebo: 3.93, pantoprazole 20 mg: 2.91, pantoprazole 40 mg: 2.71, ITT) and the number of antacid tablets taken (average number, placebo: 0.68, pantoprazole 20 mg: 0.45, pantoprazole 40 mg: 0.33, ITT) were significantly higher in the placebo than in both pantoprazole groups (p<0.0001), with no statistically significant difference between the two pantoprazole groups. The discontinuation rate due to insufficient control of heartburn was significantly lower in both pantoprazole groups compared to placebo (placebo: 10.9, pantoprazole 20 mg: 2.8, pantoprazole 40 mg: 0.9, ITT). CONCLUSIONS: Our findings favor on-demand treatment with pantoprazole 20 mg for the long-term management of heartburn in patients with uncomplicated GERD (grade 0/I) with superiority to placebo.

A randomized comparative study of esomeprazole 40 mg versus pantoprazole 40 mg for healing erosive oesophagitis: the EXPO study.

AIM: To assess the efficacy of the 8-week therapy with esomeprazole 40 mg vs. pantoprazole 40 mg for healing erosive oesophagitis (EE) as part of a management study. METHODS: Patients had a history of gastro-oesophageal reflux disease symptoms (> or =6 months) and had suffered heartburn on at least 4 of the 7 days preceding enrollment. Endoscopies were performed to grade EE severity using the Los Angeles (LA) classification system at baseline, 4 and 8 weeks (if unhealed at 4 weeks). Heartburn severity was recorded by patients on diary cards. The primary end point was healing of EE by week 8 of treatment. RESULTS: Of 3170 patients randomized, the intent-to-treat population consisted of 3151 patients (63% male, mean age: 50.6 years, 27% Helicobacter pylori-positive). Esomeprazole 40 mg healed a significantly greater proportion of EE patients than pantoprazole 40 mg at both 4 weeks (life table estimates: esomeprazole 81%, pantoprazole 75%, P < 0.001) and 8 weeks (life table estimates: esomeprazole 96%, pantoprazole 92%, P < 0.001). The median time to reach sustained heartburn resolution was 6 days in patients receiving esomeprazole and 8 days with pantoprazole (P < 0.001). CONCLUSION: Esomeprazole 40 mg is more effective than pantoprazole 40 mg for healing EE and providing resolution of associated heartburn.

European multicentre validation trial of two new non-invasive tests for the detection of Helicobacter pylori antibodies: urine-based ELISA and rapid urine test.

AIM: Non-invasive tests for the assessment of Helicobacter pylori status are now an integral part of the management strategies for patients with dyspepsia. The aim of this study was to evaluate a urine based antibody ELISA and a near patient urine test for the diagnosis of H. pylori infection in a European population. METHODS: Urine samples were collected from 449 patients (240 females, 209 males, mean age 54 years), with dyspeptic symptoms but no previous H. pylori eradication therapy, at five centres in four European countries. All patients underwent GI endoscopy and biopsies were taken for H. pylori diagnosis. Urine samples were analysed using an IgG ELISA (URINELISA) and a near patient urine test (RAPIRUN). In addition, a serum IgG ELISA (Pyloriset-EIA-GIII), a whole blood test (Pyloriset-Screen) and a 13C-urea breath test were performed. RESULTS: The sensitivity of the urine based ELISA and the near patient urine test was 90% and 82%, and the specificity 68% and 83%, respectively. The accuracy of the serum ELISA and the whole blood test was comparable with the urine based test. CONCLUSION: The urine based ELISA and the near patient urine test are just as accurate as the serological tests. This comparable accuracy and complete non-invasiveness of the former gives it an advantage over blood based tests. This limits the application of these tests in general practice.

Comparable efficacy of pantoprazole and omeprazole in patients with moderate to severe reflux esophagitis. Results of a multinational study.

AIM: To compare the efficacy and tolerability of pantoprazole 40 mg and omeprazole MUPS 40 mg in patients with moderate to severe gastroesophageal reflux disease (GERD). METHODS: In this randomized, double-blind, parallel-group, multicenter study conducted in Austria, Germany, Portugal, Switzerland and The Netherlands, patients with endoscopically confirmed moderate to severe GERD (Savary/Miller esophagitis grade II/III) were enrolled. They received a once-daily dose of either 40 mg pantoprazole or 40 mg omeprazole MUPS. Healing was determined by endoscopy after 4 weeks of treatment. If patients were not healed, treatment was extended for another 4 weeks. An additional endoscopy was performed in these cases after 8 weeks of treatment. Healing was determined by endoscopy after 4 and 8 weeks. In addition, treatment effect on symptoms was evaluated by the investigator using a questionnaire assessing heartburn, reflux regurgitation and pain on swallowing at each visit, as well as by a self-administered questionnaire comprising further 24 gastrointestinal symptoms. Analyses were performed for the intention-to-treat (ITT) and the per-protocol (PP) population. In addition, patients with high compliance (HC: 90%

Noncontact, laser-mediated extraction of polar bodies for prefertilization genetic diagnosis.

PURPOSE: We tested an entirely noncontact polar body-extraction method using an ultraviolet laser beam for laser zona drilling and a near infrared laser beam for polar body (PB) trapping and extraction. METHODS: A hole was drilled into the zona pellucida of an oocyte. Then, the PB was trapped with optical tweezers and dragged through the drilled hole. RESULTS: Bovine first PBs could be extracted in 49 out of 63 oocytes (78%) using this method. In human oocytes, PB extraction was successfully demonstrated, which however was more time consuming. A number of extracted PBs were dried on a special membrane, circumcised with the laser microbeam, and successfully catapulted into the lid of a microfuge tube (laser pressure catapulting). CONCLUSIONS: This solely laser-mediated extraction method allows convenient procurement of PBs without the danger of contamination and is a promising approach that might replace standard micromanipulation methods in the future.

A novel mechanism of nuclear photosynthesis gene regulation by redox signals from the chloroplast during photosystem stoichiometry adjustment.

Photosynthetic organisms acclimate to long term changes in the environmental light quality by an adjustment of their photosystem stoichiometry to maintain photosynthetic efficiency. By using light sources that predominantly excite either photosystem I (PSI) or photosystem II (PSII), we studied the effects of excitation imbalances between both photosystems on nuclear PSI gene transcription in transgenic tobacco seedlings with promoter::beta-glucuronidase gene fusions. Shifts from PSI to PSII light sources (and vice versa) induced changes in the reduction/oxidation state of intersystem redox components, and acclimation of tobacco seedlings to such changes were monitored by changes in chlorophyll a/b ratios and in vivo chlorophyll a fluorescence. The ferredoxin-NADP(+)-oxidoreductase gene promoter did not respond to these treatments, those from the genes for subunits PsaD and PsaF of PSI are activated by a reduction signal, and the plastocyanin promoter responded to both reduction and oxidation signals. Additional experiments with photosynthetic electron transport inhibitors 3-(3',4'-dichlorophenyl)-1,1'-dimethyl urea and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone demonstrated that the redox state of the plastoquinone pool controls the activity of the plastocyanin promoter, whereas subunit PsaD and PsaF gene transcription is regulated by other photosynthesis-derived signals. Thus, the expression of nuclear-encoded PSI genes is controlled by diverse light quality-dependent redox signals from the plastids during photosystem stoichiometry adjustment.

Functional food ingredients against colorectal cancer. An example project integrating functional genomics, nutrition and health.

Functional Food Ingredients Against Colorectal Cancer is one of the first European Union funded Research Projects at the cross-road of functional genomics [comprising transcriptomics, the measurement of the expression of all messengers RNA (mRNAs) and proteomics, the measurement of expression/state of all proteins], nutrition and human health. The goal of Functional Food Ingredients Against Colorectal Cancer is to develop a colon epithelial cell line-based screening assay for nutrients with presumed anti-colorectal carcinogenic properties. Genes involved in colon carcinogenesis are identified at the RNA and protein level, using a variety of methods (subtractive hybridisation, DNA microarray, proteomics) in combination with models for colorectal cancer development (human biopsies, rat model for colorectal carcinogenesis, colorectal cancer epithelial cell lines). Secondly, colorectal cancer epithelial cell lines are selected, in terms of their capacity to undergo gene/protein expression changes representing different phases in the colorectal carcinogenesis. Thirdly, these cell lines are used to determine the effects of nutrients with presumed anti-carcinogenic properties (e.g. resveratrol, flavonoids) on functional genomics-derived endpoints. Once validated against the effects of these nutrients in in vivo animal models and classical biomarkers for colorectal carcinogenesis, these cell line models combined with functional genomics represent useful tools to study colorectal carcinogenesis and screen for nutrients with anti-carcinogenic properties.

[Helicobacter pylori and gastroesophageal reflux disease]. / Helicobacter pylori und gastroösophageale Refluxkrankheit.

The latest accessible data indicate, that Helicobacter pylori (H.p.) infection, particularly by cagA-positive strains, protects against the development of gastroesophageal reflux disease (GERD) and its complications. Various epidemiological, pathophysiological and clinical studies demonstrate this protective effect, which is dependent on the extent of H.p. induced gastritis. Severe corpus gastritis may cause a profound reduction of acid secretion. In regard to acute or chronic PPI therapy of GERD the biological antisecretory effect of H.p. is of minor benefit. Development of atrophic gastritis in patients with GERD treated chronically with PPI is still uncertain. On account of the protective effect of H.p. against GERD, it is prudent to reserve H.p. eradication for the well-established indications.

Cell viability in optical tweezers: high power red laser diode versus Nd:YAG laser.

Viability of cultivated Chinese hamster ovary cells in optical tweezers was measured after exposure to various light doses of red high power laser diodes (lambda = 670-680 nm) and a Nd:yttrium-aluminum-garnet laser (lambda = 1064 nm). When using a radiant exposure of 2.4 GJ/cm2, a reduction of colony formation up to a factor 2 (670-680 nm) or 1.6 (1064 nm) as well as a delay of cell growth were detected in comparison with nonirradiated controls. In contrast, no cell damage was found at an exposure of 340 MJ/cm2 for both wavelengths, and virtually no lethal damage at 1 GJ/cm2 applied at 1064 nm. Cell viabilities were correlated with fluorescence excitation spectra and with literature data of wavelength dependent cloning efficiencies. Fluorescence excitation maxima of the coenzymes NAD(P)H and flavins were detected at 365 and 450 nm, respectively. This is half of the wavelengths of the maxima of cell inactivation, suggesting that two-photon absorption by these coenzymes may contribute to cellular damage. Two-photon excitation of NAD(P)H and flavins may also affect cell viability after exposure to 670-680 nm, whereas one-photon excitation of water molecules seems to limit cell viability at 1064 nm.

Isolation by size of epithelial tumor cells : a new method for the immunomorphological and molecular characterization of circulatingtumor cells.

We have developed a new assay, ISET (isolation by size of epithelial tumor cells), which allows the counting and the immunomorphological and molecular characterization of circulating tumor cells in patients with carcinoma, using peripheral blood sample volumes as small as 1 ml. Using this assay, epithelial tumor cells can be isolated individually by filtration because of their larger size when compared to peripheral blood leukocytes. ISET parameters were defined using peripheral blood spiked with tumor cell lines (HepG2, Hep3B, MCF-7, HeLa, and LNCaP). ISET can detect a single, micropipetted tumor cell, added to 1 ml of blood. We also demonstrate that fluorescence in situ hybridization can be used to perform chromosomal analyses on tumor cells collected using ISET. Polymerase chain reaction-based genetic analyses can be applied to ISET-isolated cells, and, as an example, we demonstrate homozygous p53 deletion in single Hep3B cells after filtration and laser microdissection. Finally, we provide evidence for the in vivo feasibility of ISET in patients with hepatocellular carcinoma undergoing tumor resection. ISET, but not reverse transcriptase-polymerase chain reaction, allowed analysis of cell morphology, counting of tumor cells, and demonstration of tumor microemboli spread into peripheral blood during surgery. Overall, ISET constitutes a novel approach that should open new perpectives in molecular medicine.

Diagnosis of papillary thyroid carcinoma is facilitated by using an RT-PCR approach on laser-microdissected archival material to detect RET oncogene activation.

OBJECTIVE: The purpose of this study was to investigate the value of the expression of the RET oncogene (rearranged during transfection) in papillary thyroid carcinomas (PTC) and its variants in the differential diagnosis of thyroid neoplasias. According to the literature RET oncogene activation by chromosomal rearrangements has been exclusively implicated in PTCs. METHODS: To establish the incidence of RET activation in PTCs we used 5- to 10-microm sections from archival paraffin blocks. Either parts of the tissue slices were manually dissected or a few distinct cells were microdissected by laser-mediated manipulation with the Robot-MicroBeam system. RNA was extracted from paraffin-embedded thyroid tumors and the corresponding normal tissue. RT and nested PCR were performed using primers for RET/PTC1, PTC2 and PTC3, or for RET exons 12 and 13. PCR products were resolved by gel electrophoresis. RESULTS: We detected RET transcription in approximately 85% of the PTCs including follicular variants and in isolated cells of the same tissues, but not in nonmalignant thyroid tissue. CONCLUSIONS: Our method may serve as an additional diagnostic tool to characterize ambiguous neoplasias and to identify especially nonpapillary, i.e. follicular tumors, as papillary carcinomas. Additionally, this study has demonstrated that expressed genes can be analyzed from routine histopathological tissue slides or pooled single cells. Large retrospective studies can also be performed with this method.

Laser microdissection as a new approach to prefertilization genetic diagnosis.

The genetic status of oocytes can be determined by polar body (PB) analysis. Following PB extraction, a genetic evaluation is performed. As each PB contains the complementary genetic material of the oocyte, PB analysis reveals information about its genetic status. Genetically altered oocytes may then be excluded from in vitro fertilization. The aim of our study was to evaluate laser microdissection as a tool for PB extraction purposes. Compared to the PB extraction with a sharp-ending pipette only, we could show that laser microdissection of the zona pellucida (laser zona drilling) with a UV-A laser and subsequent extraction with a blunt-ending pipette decreases the degeneration rate of oocytes. It is shown that laser pressure catapulting of extracted PB enables their contact-free transfer into tubes, thus decreasing the risk of contamination for further analysis.

Technical advance: single pollen typing combined with laser-mediated manipulation.

We combined single pollen typing with laser-mediated manipulation. After drilling a hole in the wall of a pollen grain from a dioecious plant (Silene latifolia) with a UV-laser microbeam, the single pollen grain was recovered directly in the cap of a PCR tube, using a non-contact method called laser pressure catapulting. The entire genome of the single pollen grain was then amplified with improved primer-extension-preamplification PCR (I-PEP PCR). Nested PCR with sequence tagged site (STS)-specific primers was used to analyze several loci in the haploid genome. The single copy gene MROS1 was detected in most of the single pollen grains analyzed. Bgl10, which is localized on the Y chromosome, was detected in approximately half of the pollen grains. MROS3 is reported to be localized on the X chromosome. Using inverse PCR, we isolated two genomic clones of MROS3: MROS3A and MROS3B. The single pollen analysis using nested PCR showed that MROS3A and MROS3B are derived from different loci that are not located on the X chromosome. Single pollen typing not only reveals sex chromosome-linkage within the haploid genome, but can also discriminate between alleles and different loci. This method should also be useful for measuring recombination frequencies without genetic crossover analysis.

Effect of omeprazole and amoxicillin plus metronidazole on the eradication of Helicobacter pylori and the healing of duodenal ulcer: comparison with a historical control.

BACKGROUND/AIMS: To test the hypothesis of equivalence of an omeprazole 7-day triple therapy without subsequent acid suppression and a historical ranitidine 12-day triple therapy (recruiting phase 1989-91) with subsequent acid suppression in their effect on the eradication of Helicobacter pylori (H. pylori) and the healing of duodenal ulcer. METHODOLOGY: Seventy-seven patients with H. pylori-positive duodenal ulcers received a 7-day treatment with amoxicillin 750 mg tid and metronidazole 500 mg tid. Additional omeprazole 20 mg or 40 mg once daily was given to 39 and 38 of the patients, respectively. Endoscopy was performed before treatment and four weeks after cessation of therapy. RESULTS: The cumulative intention-to-treat (ITT) H. pylori-eradication rate was 66% (51/77) as compared to 89% (46/52) for the historical control (p < 0.05). The corresponding ulcer healing rates were 90% (69/77) and 92% (48/52). Primary metronidazole resistance (PMR) had escalated from 10% to 27% within 6 years resulting in eradication rates of 84% for sensitive and 19% for resistant strains (p < 0.001). PMR could be demonstrated in 45% of all female, but only in 17% of the male patients (p < 0.05). In the patients with H. pylori eradication, the ulcers healed in 98% (50/51) as compared to 73% (19/26) in those with persistent infection (p < 0.005). Analysis based on the presence of PMR showed ulcer healing rates of 95% (53/56) for sensitive and 76% (16/21) for resistant strains (p < 0.05). Improvement of pain also showed a significant correlation with successful eradication. H. pylori-eradication, healing and symptom relief were similar in the omeprazole 20 mg and 40 mg groups. CONCLUSIONS: The effect of amoxicillin plus metronidazole plus antisecretory agent on the eradication of H. pylori has decreased markedly during the past 6 years due to the escalation of PMR. Doubling of the omeprazole dose does not affect outcome. Cure of the infection as well as metronidazole susceptibility enhance duodenal ulcer healing and symptom relief. Acid suppression following a successful 1-week anti-HP therapy is not required for duodenal ulcer treatment.

CD87-positive tumor cells in bone marrow aspirates identified by confocal laser scanning fluorescence microscopy.

Dissemination of single tumor cells to the bone marrow is a common event in cancer. The clinical significance of cytokeratin-positive cells detected in the bone marrow of cancer patients is still a matter of debate. In gastric cancer, overexpression of the receptor (uPAR or CD87) for the serine protease urokinase-type plasminogen activator (uPA) in disseminated cancer cells indicates shorter survival of cancer patients. A new immunofluorescence approach, applying confocal laser scanning microscopy, is introduced to locate CD87 antigen in cytokeratin-positive tumor cells and to quantify the CD87 antigen by consecutive scanning. At first, cytokeratin 8/18/19-positive carcinoma cells are identified at excitation wavelength 488 nm using monoclonal antibody A45B/B3 to the cytokeratins and goat anti-mouse IgG labeled with the fluorochrome Alexa488. Next, CD87 in tumor cells is identified by chicken antibody HU277 to the uPA-receptor and goat anti-chicken IgY labeled with fluorochrome Alexa568 (excitation wavelength 568 nm) and the fluorescence signal quantified on a single cell basis using fluorescently labeled latex beads as the fluorescence reference. From 16 patients with gastric or esophageal carcinoma, bone marrow aspirates were obtained, stained for cytokeratins and CD87 and then subjected to laser scanning fluorescence microscopy. Three of six gastric cancer patients had tumor cells present in the bone marrow of which 2 stained for CD87. Three of ten esophageal carcinoma patients had tumor cells in the bone marrow, all three samples stained for CD87. CD87-positive tumor cells were also dissected from stained bone marrow aspirates by laser microdissection microscope to allow analysis of single cells at the gene level.

Famotidine versus omeprazole in combination with clarithromycin and metronidazole for eradication of Helicobacter pylori--a randomized, controlled trial.

BACKGROUND: One-week low-dose triple therapy is currently considered the gold standard regimen for treatment of Helicobacter pylori infection. However, the mechanisms involved in the synergy between antibiotics and proton pump inhibitors are controversial. AIMS: To test the hypothesis that acid suppression represents the crucial mechanism by which the antibacterial activity of antibiotics can be enhanced, and to assess the impact of primary resistance on treatment outcome. METHODS: One hundred and twenty patients with H. pylori infection and duodenal ulcer, gastric ulcer or non-ulcer dyspepsia were randomly assigned to a 1 week course of either famotidine 80 mg b.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (FCM group; n = 60) or omeprazole 20 mg o.d., clarithromycin 250 mg b.d. and metronidazole 500 mg b.d. (OCM group; n = 60). Gastroscopy was performed at baseline and 5 weeks after completion of treatment. H. pylori status was assessed by biopsy urease test, histology and culture. RESULTS: In the intention-to-treat analysis, eradication of H. pylori was achieved in 47 of 60 patients (78%; 95% CI: 66-88%) in the FCM group, compared to 44 of 60 patients (73%; 95% CI: 60-84%) in the OCM group (N.S.). Using per protocol analysis, eradication therapy was successful in 47 of 52 patients (90%; 95% CI: 79-97%) treated with FCM and 44 of 57 patients (77%; 95% CI: 64-87%) treated with OCM (N.S.). Primary metronidazole resistance was present in 27% and primary clarithromycin resistance in 8% of strains. Overall per protocol eradication rates in strains susceptible to both antibiotics and strains with isolated metronidazole resistance were 93% and 84%, respectively. No patient with clarithromycin resistance responded to treatment. CONCLUSIONS: High-dose famotidine and omeprazole, combined with clarithromycin and metronidazole, are equally effective for eradication of H. pylori. In 1-week low-dose triple therapy, metronidazole resistance has no major impact on eradication rates whereas clarithromycin resistance is associated with a poor treatment outcome.