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Biomedical subjects

W A de Boer

Publications and source records attributed to W A de Boer.

At least 19 recordsLinked to original sources
PubMed2006

Helicobacter pylori antibiotic resistance in a Dutch region: trends over time.

AIM: Most patients treated for H. pylori infection receive empirical therapy based on epidemiological data of antibiotic resistance. However, previous European studies indicate that resistance patterns may be changing. Therefore, the aim of this study was to investigate the prevalence of primary clarithromycin and/or metronidazole resistant H. pylori strains over a six-year period (1997-2002) in a regional hospital. METHODS: All patients visiting Slingeland Hospital in Doetinchem, the Netherlands between 1997 and 2002 with a positive H. pylori culture were included in this study. Susceptibility to metronidazole and clarithromycin was determined by disk diffusion. RESULTS: Of the 1355 patients with an H. pylori positive culture, 1127 did not have a history of H. pylori eradication, 58 did, and for 170 this information was not available. Mean rates of primary resistance to metronidazole and clarithromycin were 14.4% (162/1125) and 1.0% (11/1123), respectively. Primary metronidazole resistance was stable throughout the study period and primary clarithromycin resistance showed a decreasing trend. Patients of foreign descent and from secondary care had a higher chance of harbouring primary metronidazole-resistant H. pylori (adjusted OR (95% CI) 1.75 (1.1 to 2.8), and 1.60 (1.1 to 2.2), respectively). Patients with failed H. pylori eradication had a higher chance of harbouring metronidazole-resistant H. pylori (43 vs 14%, p<0.0001) and clarithromycin-resistantH. pylori (5.3 vs 1.0%, p=0.004) than untreated patients. CONCLUSION: Primary metronidazole resistance is stableat a low level, while primary clarithromycin resistance isvirtually absent in the eastern part of the Netherlands.Therefore, triple therapy with a proton pump inhibitor,clarithromycin and amoxicillin can remain the empiricaltreatment of choice in the Netherlands.

Amoxicillin↗
PubMed2006

Validation of a new, commercially available dry rapid urease test for the diagnosis of Helicobacter pylori infection in gastric biopsies.

BACKGROUND: To compare the accuracy and reaction time of a new dry rapid urease test (GUT test) with the CLO test and an independent gold standard in the diagnosis of Helicobacter pylori infection. To determine whether this new test can replace the CLO test in routine clinical practice. METHODS: We included consecutive patients in whom normal-sized gastric biopsies were taken in routine practice. six antral and three corpus biopsies were taken for determination of H. pylori infection. results of the GUT test were monitored after 15, 60 and 120 minutes of incubation. Results were compared with the standard CLO test and an independent gold standard (bacterial culture and histology). The results of the CLO test were also compared with the gold standard. RESULTS: 116 patients were recruited in the study: 60 were males and 56 females. The mean age was 59.3 years (range 14-89 years). Compared with the CLO test, the GUT test had a sensitivity of 76.7% and a specificity of 100% in 15 minutes. After 60 minutes the sensitivity of the GUT test increased to 95.3%, the specificity remained 100%. All positive results of the GUT test occurred before 60 minutes of incubation. Compared with the gold standard, the GUT test had a sensitivity and specificity of 97.4 and 96.1% respectively. The CLO test had a sensitivity of 97.4% and a specificity of 93.5%, when compared with the gold standard. CONCLUSION: The GUT test appeared to be a good and reliable alternative for the widely used Clo test in diagnosing H. pylori infection. The GUT test results were not yet reliable after 15 minutes, but all positive results occurred before 60 minutes of incubation. The test can best be read 60 to 120 minutes after endoscopy.

Adolescent↗
PubMed2005

[Low prevalence of metronidazole- and clarithomycin-resistant Helicobacter pylori in the 's-Hertogenbosch region, 1998-2003].

OBJECTIVE: To measure the prevalence of metronidazole- or clarithromycin-resistant Helicobacter pylori. DESIGN. Retrospective. METHOD: All positive H. pylori cultures with known susceptibility to metronidazole or clarithromycin between 1998 and 2003 were selected from the database of the Microbiology Laboratory in 's-Hertogenbosch, the Netherlands. Resistance to clarithromycin and metronidazole was determined using the E-test with cut-off minimum inhibitory concentrations of > or = 2 microg/ml and > or = 8 microg/ml, respectively. RESULTS: Of the 960 cultures with known metronidazole susceptibility, 135 (14%) were resistant. Of the 959 cultures with known clarithromycin susceptibility, 26 (3%) were resistant. The percentages of resistant cultures were higher in women than in men (17% versus 12% and 4% versus 2%, respectively). There was no relationship between age and resistance. Over the course of the study period, resistance to metronidazole decreased slightly, whereas resistance to clarithromycin increased slightly. CONCLUSION: Prevalence of metronidazole- and clarithromycin-resistant H. pylori strains in the 's-Hertogenbosch region was so low that the combination of a proton pump inhibitor, clarithromycin and amoxicillin can be used in patients with H. pylori infection without first determining susceptibility.

Anti-Bacterial Agents↗
PubMed2005

Meta-analysis: the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication.

BACKGROUND: There is much debate about the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication. The few studies investigating the influence of pre-treatment on triple and quadruple therapies did not find differences in eradication rates. However, the high eradication rates make it difficult to study factors associated with therapy failure in small populations. In order to overcome this problem we performed a meta-analysis. METHODS: The literature was searched in order to identify randomized clinical trials comparing modern triple/quadruple therapies for H. pylori eradication without pre-treatment with a proton pump inhibitor with exactly the same regimen with pre-treatment. The overall risk difference (with - without pre-treatment) was calculated by pooling the risk differences of the individual studies weighted by the inverse of their variances. RESULTS: Nine studies, investigating a total of 773 patients, were identified. There was considerable variation regarding therapy regimen and duration. Pooled eradication rates were 81.3% (312 of 384) for patients with pre-treatment and 81.2% (316 of 389) for patients without pre-treatment. The (weighted) overall risk difference was 0.1% (95% CI: -5%; 5%). CONCLUSION: Pre-treatment with a proton pump inhibitor does not influence H. pylori eradication.

Anti-Bacterial Agents↗
PubMed2005

The importance of corpus biopsies for the determination of Helicobacter pylori infection.

BACKGROUND: The aim of this study was to determine whether an antral biopsy alone represents an adequate tissue sample to diagnose the presence of Helicobacter pylori on the mucosa. Furthermore, we explored the conditions associated with the presence of H. pylori in the corpus. METHODS: Consecutive patients who underwent an upper gastrointestinal endoscopy at a single centre between January 1995 and May 1997 were studied. Biopsies were taken at each endoscopy to assess the presence of H. pylori: two antral and two corpus biopsies for histological examination and one antral and one corpus biopsy for the CLO test. RESULTS: A total of 620 patients underwent an upper gastrointestinal endoscopy, 307 (50%) were H. pylori infected. In 80% of the endoscopies there was total agreement between the performed biopsy tests. The addition of corpus biopsies increases the diagnostic yield by 10% in H. pylori-positive patients. Patients with only corpus infection more often showed atrophy and intestinal metaplasia compared with patients with both antral and corpus infection, 37 vs 20%, respectively (OR 2.2, 95% CI 1.1-4.4). CONCLUSION: One biopsy from the antrum or corpus seems to be inadequate to diagnose the presence of H. pylori on the mucosa. Patients with an infection exclusively in the corpus more often had worse mucosa pathology.

Adolescent↗
PubMed2004

The influence of pretreatment on cure rates of Helicobacter pylori eradication.

BACKGROUND: Many patients treated for H. pylori infection have been taking a proton pump inhibitor beforehand. There is conflicting evidence whether pretreatment influences the efficacy of H. pylori eradication. The aim of this study was to investigate the influence of pretreatment on cure rates of H. pylori eradication. METHODS: Patients with H. pylori positive peptic ulcer disease or functional dyspepsia were treated with two-day quadruple therapy (lansoprazole 30 mg twice daily, and colloidal bismuth subcitrate 120 mg, tetracycline 250 mg and metronidazole 250 mg, all eight times a day). Patients were randomised to receive either three-day pretreatment with lansoprazole 30 mg twice daily or no pretreatment. H. pylori was diagnosed using CLO, histology and culture. RESULTS: Twenty-five (66%) of 38 patients with pretreatment and 32 (84%) of 38 patients without pretreatment were cured (p=0.06). After adjustment for diagnosis, smoking status and metronidazole resistance the influence of pretreatment became slightly less pronounced (OR 0.44, 95% CI 0.1-1.7). Nonsmokers and patients with peptic ulcer disease were more likely to achieve H. pylori eradication than smokers and patients with functional dyspepsia, respectively (adjusted odds ratios: 4.79 (1.2-19) and 4.32 (1.0-18)). CONCLUSIONS: This two-day quadruple therapy reached an overall cure rate of 75%. Nonsmokers and patients with peptic ulcer disease were more likely to achieve H. pylori eradication. Three-day pretreatment with a proton pump inhibitor may decrease cure rates of this two-day quadruple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Comparison of four-day and seven-day pantoprazole-based quadruple therapy as a routine treatment for Helicobacter pylori infection.

BACKGROUND: H. pylori eradication is usually performed with three or four drugs for at least seven days. Recently four reports have shown a cure rate of approximately 90% using a four-day quadruple therapy. The objectives of this prospective study were: 1) to evaluate the efficacy of pantoprazole-based quadruple therapy, and 2) to compare the efficacy and tolerability of four-day with seven-day quadruple therapy. METHODS: The study was performed in a single centre. The first 56 consecutive patients with nonulcer dyspepsia or peptic ulcer disease and proven H. pylori infection received seven days of quadruple therapy (pantoprazole, bismuth, tetracycline and metronidazole). At least six weeks after treatment, endoscopy was repeated with six biopsies of the antrum and corpus for histology, urease test and culture. The next 59 consecutive patients followed the same protocol but received four-day quadruple therapy. RESULTS: Using an intention-to-treat analysis, the cure rate in the seven-day treatment group was 54/56 (96.4%, 95% confidence interval (CI) 87.7-99.6%). In the per protocol analysis the cure rate was 53/55 (96.3%, 95% CI 87.5-99.6%). Primary metronidazole resistance was observed in seven patients. All were cured. Using an intention-to-treat analysis, the cure rate in the four-day treatment group was 51/59 (86.4%, 95% CI 75.0-94.0%). In the per protocol analysis the cure rate was 50/58 (86.2%, 95% CI 74.6-93.8%). Primary metronidazole resistance was observed in seven patients, four of whom were cured. In three out of eight patients in whom four-day treatment failed, secondary metronidazole resistance was induced. Both treatment regimens were well tolerated. The difference between cure rates of both regimens did not reach statistical significance (p=0.0585). CONCLUSION: Routine use of both four-day and seven-day pantoprazole-based quadruple anti-H. pylori treatment is effective and well tolerated. The results of both regimens reach the required eradication standard, but results with the seven-day regimen were slightly but not significantly better. Seven-day treatment may be superior, especially in case of metronidazole resistance, and should be preferred.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Should anti-Helicobacter therapy be different in patients with dyspepsia compared with patients with peptic ulcer diathesis?

Physicians should try to reach an optimal cure rate with initial anti-Helicobacter therapy. Helicobacter pylori infection in patients with peptic ulcer disease (PUD) is more likely to be cured then in patients with 'functional' dyspepsia (FD). Differences in cure rates of 5-15% are usually reported, which is considered to be clinically relevant. Different strains (virulent v. non-virulent) in PUD and FD may induce different alterations in the gastric mucosa, and thereby either facilitate or impair antimicrobial efficacy. A study in this journal showed that triple therapy with ranitidine bismuth citrate (RBC) was superior to triple therapy with a proton pump inhibitor (PPI), but only in the more-difficult-to-cure FD patients. Clinicians should be aware that most published treatment studies have included only PUD patients. This means that in clinical practice the cure rates obtained in patients with FD or even uninvestigated dyspepsia will usually be lower then those reported in the literature. One way to deal with this is to consider prolonging the duration of an initial anti-Helicobacter therapy from 7 to 10 or 14 days in patients without ulcers.

Anti-Ulcer Agents↗
PubMed2001

Eradication of Helicobacter pylori restores glutathione S-transferase activity and glutathione levels in antral mucosa.

Glutathione S-transferases (GST) and glutathione peroxidases (GPO) are important in detoxification. GST activity in the mucosa of the gastrointestinal tract is inversely correlated with the development of gastrointestinal cancer. Helicobacter pylori (H. pylori) infection has been associated with gastric cancer. We studied GST activity and the substrate glutathione (GSH) in patients with H. pylori-associated gastritis. GST activity and isoenzyme levels, GPO activity and GSH levels were studied in antral biopsies of 38 H. pylori-positive patients, before and after eradication treatment. In 31 patients in whom H. pylori was successfully eradicated, antral GST enzyme activity before therapy was 532 (465 - 598) nmol / mg protein. min (mean and 95% confidence interval) and that after therapy was 759 (682 - 836) nmol / mg protein. min (P < 0.0001). Correspondingly, levels of GST alpha and GST-P1 were higher after eradication (P < 0.001). GSH concentration significantly increased: 21.2 (16.2 - 26.2) nmol / mg protein before and 27.1 (23.6 - 30.6) nmol / mg protein after therapy (P < 0.05). In 7 patients in whom H. pylori was not eradicated, GST activity was 671 (520 - 823) nmol / mg protein. min and 599 (348 - 850) nmol / mg protein before and after treatment respectively (P = 0.32). GSH levels were 17.4 (9.0 - 25.7) nmol / mg protein and 18.2 (9.1 - 27.3) nmol / mg protein, respectively (P = 0.84). No differences in antral GPO enzyme activity, both of selenium (Se)-dependent and total GPO, before and after successful treatment were found. Eradication of H. pylori infection increases GST activity and GSH levels in antral mucosa. Low GST activity and GSH concentration due to H. pylori infection might play a role in gastric carcinogenesis.

Adult↗
PubMed2001

A novel therapeutic approach for Helicobacter pylori infection: the bismuth-based triple therapy monocapsule.

Helicobacter pylori infection causes peptic ulcer disease and must be regarded as a serious infectious disease. Over the past two decades treatment of the infection has been a controversial issue. Treatment is purely empirical and based on combinations of two, three or four existing drugs. Antimicrobial resistance is important and an observed increase in the prevalence of resistance may change the relative importance of certain antibiotics. Bismuth-based triple therapy with bismuth, tetracycline and metronidazole is a well investigated, cheap and FDA approved regimen to cure the infection. Adding a proton pump inhibitor (PPI) increases efficacy. A novel monocapsule ("Helicide") that contains bismuth, tetracycline and metronidazole simplifies the regimen. This new and patient-friendly drug has been investigated in clinical studies and is expected to be released in North America in 2002.

Antacids↗
PubMed2000

Diagnostic performance of biopsy-based methods for determination of Helicobacter pylori infection without a reference standard.

Endoscopic biopsy-based tests are considered to be the reference method for diagnosing Helicobacter pylori infection and monitoring antibiotic treatment, but unbiased data on their diagnostic performance is lacking. In this study we evaluated the diagnostic performance of culture, histology and rapid urease testing of antral biopsies separately and in combination. Antral biopsies were taken from consecutive patients undergoing upper gastrointestinal endoscopies at a single center between January 1995 and May 1997. The biopsies were examined for culture, histology, and CLOtest. The diagnostic performance, i.e., the sensitivity and specificity of the tests was estimated with 7 non-linear equations in 7 unknowns. To determine sources of heterogeneity that may have biased the results, data were stratified for age, gender, and whether they were taken before or after anti-Helicobacter antibiotic treatment. During the study period 631 patients underwent 869 upper gastrointestinal endoscopies. In 122 (14%) of the antral specimens the test results of culture, histology and CLOtest differed. Based on the nonlinear regression techniques we estimated that in 347 tests (40%) H. pylori infection was present. Overall sensitivity, specificity, positive and negative predictive value for each test were as follows: culture 91.4%, 96.3%, 94.2%, 94.4%, respectively; histology 90.3%, 97.8%, 96.4%, 93.8%, respectively; CLOtest 94.9%, 96.7%, 95.0%, 96.6%, respectively. In combination, the three tests provided the definitive diagnosis, either non-infected or infected, in 862 out of the 869 tests. Sensitivity of gastric antral histology was 64.9% (95% CI: 38-86) in females who did and 84.5% (95% CI: 77-90) in females who did not have had recent antibiotic therapy to cure the infection. Approximately 5-10% of H. pylori infected patients, were mis-diagnosed with a single biopsy-based test taken from the gastric antrum. Only a combination of bacterial culture, histological examination and the CLOtest represents an appropriate reference standard for research purposes to identify infected patients.

Adult↗
PubMed2000

Costs and benefits of a test-and-treat strategy in Helicobacter pylori-infected subjects: a prospective intervention study in general practice.

OBJECTIVE: To identify health outcomes and costs/savings of a Helicobacter pylori test-and-treat strategy in patients using acid suppressants chronically. DESIGN: Prospective intervention study. Patients were tested for H. pylori infection and treated with 14 days of ranitidine bismuth citrate (RBC) 400 mg (b.i.d.) and clarithromycin 500 mg if infected. Cure was determined after six months. SETTING: General practice. PARTICIPANTS: Patients using acid suppressants chronically were identified by a computer search; 184 patients gave written consent and were included. MAIN OUTCOME MEASURES: Serology, symptom questionnaire, medication history, quality of life determination, costs/savings. RESULTS: Out of 184 patients, 85 (46%) had positive serology. A cure rate of 61/80 (76%) was achieved. The intervention group showed significant symptom relief. Benefits were evident in patients with ulcer disease but also in patients with uninvestigated dyspepsia. Quality of life improved for cured patients in the intervention group. No improvements for dyspeptic symptoms or quality of life occurred in the H. pylori-negative group. After six months, significant savings for medication use had occurred in treated patients diagnosed as ulcer disease or non-ulcer dyspepsia. Savings on drug use and doctor visits equalize with costs for tests and antibiotics after nine months. Although less, costs for drugs also decreased significantly in the H. pylori-negative group. Therefore, for the study population, costs and savings are even after 6.5 months. CONCLUSIONS: A test-and-treat strategy for H. pylori, systematically applied at the population level in patients using acid suppressants chronically, results in significant health benefits and economic savings within 1 year of follow-up.

Adult↗
PubMed2000

A single drug for Helicobacter pylori infection: first results with a new bismuth triple monocapsule.

OBJECTIVE: In this pilot study we investigated the efficacy and tolerability of a new monocapsule that contains a bismuth compound, tetracycline, and metronidazole. If proven to be effective, this monotherapy would turn the well-accepted multidrug regimen of standard bismuth-based triple therapy into an easy and more patient-friendly regimen. It can be used in patients allergic to penicillin. METHODS: A total of 53 consecutive H. pylori-infected patients (30 with proven ulcer disease, 23 with gastritis only) from a single center were prescribed two monocapsules q.i.d. after the three meals and after an evening snack during 10 days. Each capsule contained 60 mg colloidal bismuth subcitrate (as Bi2O3 equivalent), 125 mg tetracycline, and 125 mg metronidazole. Repeat endoscopy with biopsies for urease test, Giemsa stain, and culture was carried out > or =5 wk later. Side effect data were collected. RESULTS: One patient was lost to follow-up, two failed to respond, and 50 were cured. The intention-to-treat cure rate was 50 of 53 (94.4%, 95% CI 88.1-100%). Antibiotic sensitivity was available from 51 isolates. The cure rate in the metronidazole sensitive strains was 44 of 45 (97.8%, 95% CI: 93.5-100%), whereas it was four of five in the resistant strains. The regimen was well tolerated, with only two drop-outs (4%) because of side effects. CONCLUSIONS: The new monocapsule is an inexpensive, well tolerated, and patient-friendly formulation of a bismuth based triple therapy. A 10-day course with this multidrug capsule reached a very high cure rate in metronidazole-sensitive strains. The number of cases with resistant strains was insufficient to allow firm conclusions about its efficacy in case of resistance. The results are in agreement with previous data with bismuth triple therapy using separate drugs. From the high cure rate, we can conclude that the new capsule dissolves adequately, with proper delivery of its ingredients at the site of action.

Adult↗