Biomedical subjects

A Leodolter

Publications and source records attributed to A Leodolter.

44 records · Page 3Linked to original sources

PubMed1999

Validity of a modified 13C-urea breath test for pre- and posttreatment diagnosis of Helicobacter pylori infection in the routine clinical setting.

OBJECTIVE: Citric acid meets the criteria of an optimal test drink for the 13C-urea breath test (13C-UBT) because it permits rapid, high level recovery of the 13C administered. In a previous study we reported that administration of 13C-urea dissolved in a citric acid solution provides results similar to those obtained with standard administration of the substrate 10 min after the test drink. The aim of this study was to evaluate the accuracy of this modified 13C-UBT for both primary and posttreatment diagnosis of Helicobacter pylori (H. pylori) infection in a large patient population in clinical practice. METHODS: The 13C-UBT was performed in 553 patients with dyspeptic symptoms by giving them 75 mg of 13C-urea either 10 min after administration of 200 ml of a test drink comprising 0.1 mol/L citric acid solution (protocol 1, n = 320) or dissolved in the same amount of this test drink (protocol 2, n = 233). All patients underwent an upper gastrointestinal endoscopy and the H. pylori-status was assessed by histology, rapid urease test, and culture. Sixty patients with proven H. pylori infection were reinvestigated by both endoscopy and 13C-UBT (protocol 2) 4 wk after completing eradication therapy. RESULTS: The accuracy of the two test protocols in the pretreatment diagnosis of H. pylori infection (95.6% and 96.6%), as well as of the modified 13C-UBT in the posttreatment evaluation of the infection (98.3%) was similar. More meaningful are the high PPV (>96%) and NPV (>93%) of the 13C-UBT under pre- and posttreatment conditions. CONCLUSIONS: The administration of 13C-urea dissolved in a citric acid solution simplifies the 13C-UBT, while preserving the high accuracy in the diagnosis of H. pylori infection. This modified 13C-UBT has equal accuracy in the pre- and the posttreatment situations.

Adolescent↗

PubMed1999

Evaluation of an enzyme immunoassay for detecting Helicobacter pylori antigens in human stool samples.

BACKGROUND AND AIM: So far, the detection of Helicobacter pylori (Hp) infection by stool analysis appeared to be almost impossible. With the Premier Platinum HpSA EIA a new enzyme immunoassay was developed for diagnosis of Hp infection, using polyclonal antibodies against Hp antigens in human stool. We evaluated this new test in its diagnostic accuracy in comparison to established reference methods. METHODS: From 54 consecutive patients (29 male, 25 female, age: 19 to 85 years) undergoing routine upper gastrointestinal endoscopy antral and corpus biopsies were taken for histology and Helicobacter urease test (HUT). Endoscopy, 13C-urea breath test (13C-UBT), serology, and stool probes sampling were performed within two days. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The Premier Platinum HpSA test (Meridian, Connecticut, Ohio, USA) was performed according to the manufactures protocol. Patients were considered to be infected with Hp if two of the four reference tests were positive. RESULTS: 28 of the 54 patients were Hp-infected. Only one of these was found to be false-negative by the HpSA EIA. Two false-positive results were obtained in the noninfected group (sensitivity 96.4%, specificity 92.3%). CONCLUSION: In this group of patients investigated, the novel HpSA Enzyme Immunoassay (EIA) proved to be highly accurate for diagnosis of Hp infection. Collection and testing of stool are noninvasive and easy to perform, therefore this test will become an important tool for diagnosing Hp infection in clinical practice.

Adult↗

PubMed1998

Prevalence of Helicobacter pylori resistance to several antimicrobial agents in a region of Germany.

To evaluate the prevalence of resistance among Helicobacter pylori in Germany, the minimum inhibitory concentrations of amoxicillin, tetracycline, clarithromycin, and metronidazole were determined by means of the E test, for 271 Helicobacter pylori isolates cultured from biopsies taken during routine endoscopies in 1996 and 1997. The prevalence of metronidazole resistance was 32.1%, with resistance found more frequently in women (38.5%) than in men (24.4%). Clarithromycin resistance was rare (3.3%). Eight of nine strains resistant to clarithromycin were also resistant to metronidazole. Resistance to either metronidazole or clarithromycin was significantly (P=0.022) higher in patients with duodenal ulcer. No strain was found to be resistant to amoxicillin or tetracycline.

Adult↗

PubMed1998

13C-urea breath test for the diagnosis of Helicobacter pylori infection. A further simplification for clinical practice.

BACKGROUND: The 13C-urea breath test is the most accurate noninvasive method for the diagnosis of Helicobacter pylori infection. The oral administration of citric acid solution as test drink 10 min before administration of 13C-urea appears to be the most valuable test procedure hitherto reported. To simplify the test for clinical routine, we evaluated in a prospective, randomized, crossover study the accuracy of a new modification that consists in giving the 13C-urea dissolved in the test drink. METHODS: Forty dyspeptic patients were studied. H. pylori status was assessed by histology, rapid urease test, and culture. A 13C-urea breath test was performed on 2 consecutive days by giving 200 ml 0.1N citric acid solution either 10 min previous to (protocol 1) or simultaneously with (protocol 2) the administration of 75 mg 13C-urea in randomized order. The 13CO2/12CO2 ratio was measured in breath samples taken before and 10, 20, 30, 45, and 60 min after administration of 13C-urea. RESULTS: Twenty patients were H. pylori-positive. In these subjects maximal delta values (28.1 per thousand (21.4-34.9) versus 30.6 per thousand (22.8-38.4)), expired cumulative amount of 13C (9.3% (6.9-11.7) versus 10.2% (7.4-12.9)), and time to maximal delta value (33 min (26-39) versus 35 min (29-42)) obtained by applying test protocols 1 and 2, respectively, were similar. Both test protocols provided negative results in all H. pylori-negative subjects. The 13C-urea was stable in citric acid solution at room temperature for at least 2 weeks. CONCLUSIONS: The 13C-urea breath test for the diagnosis of H. pylori infection can be simplified by giving the substrate dissolved in the test drink. This modification is not associated with a loss of diagnostic accuracy.

Adult↗

PubMed1998

Prevalence of Helicobacter pylori infection and gastric mucosal abnormalities in chronic pancreatitis.

OBJECTIVE: Chronic pancreatitis is often associated with abnormal gastric acid secretion. However, previous studies have taken into consideration neither the potential role of Helicobacter pylori (H. pylori) infection nor histological features of the gastric mucosa in this context. The aim of this study was to analyze the prevalence of H. pylori infection as well as the pattern of gastritis in patients with chronic pancreatitis. METHODS: Forty patients with chronic alcoholic pancreatitis were included in the study: 40 patients with alcoholic liver cirrhosis and normal exocrine pancreatic function and 40 asymptomatic nonalcoholic subjects matched for age and sex used as control subjects. Endoscopy was performed in all patients, and five biopsy specimens from the antrum (three from the gastric body and two from the cardia) were taken for histological grading of gastritis and H. pylori assessment. RESULTS: Prevalence of H. pylori infection was similar in subjects with chronic pancreatitis (38%), asymptomatic subjects (28%) and liver cirrhosis (30%). Topography and expression of H. pylori-associated chronic gastritis was also not different among the three groups of subjects. In H. pylori-negative subjects, the presence of moderate to severe chronic antral gastritis was significantly more common in patients with chronic pancreatitis (40%) than in subjects with liver cirrhosis (18%) and in asymptomatic subjects (14%) (p < 0.05). No difference was found among the three groups of patients with regard to gastritis activity, atrophy, and intestinal metaplasia in the various gastric regions. The chronicity grade of gastritis did not correlate with the severity of pancreatic insufficiency. CONCLUSION: Prevalence of H. pylori infection is not different in patients with chronic pancreatitis as compared with subjects alcoholic liver cirrhosis and asymptomatic subjects. A severe H. pylori-negative chronic gastritis is more common in patients with chronic pancreatitis. This chronic inflammation of the gastric mucosa could contribute to determining the changes in gastric physiology described in patients with chronic pancreatitis.

Adult↗

PubMed1997

A citric acid solution is an optimal test drink in the 13C-urea breath test for the diagnosis of Helicobacter pylori infection.

BACKGROUND: The 13C-urea breath test (13C-UBT) is a simple, non-invasive and reliable test for the diagnosis of Helicobacter pylori infection. The duration of the test, the timing of breath sampling, and the accuracy of the method vary according to the test meal used. AIM: To identify the optimal test meal or drink for rapid and accurate performance of the 13C-UBT for the detection of H pylori infection. PATIENTS: Eighty patients with dyspeptic symptoms were included. Of these, 48 patients had a positive H pylori status and 32 a negative one according to the results of the rapid urease test, histological examination, and culture. METHODS: A 13C-UBT was performed after an overnight fast, on three consecutive days. On each study day a different test meal or drink was given (0.1 N citric acid solution, a standard semiliquid meal, or a semiliquid fatty meal) 10 minutes before giving 75 mg 13C-urea. Breath samples were collected at 0, 15, 30, 45, and 60 minutes, and analysed by isotype ratio mass spectrometry. Results were expressed as delta (delta) and considered as positive for H pylori if the highest delta (peak) was greater than 4.0. RESULTS: The delta peak obtained with the citric acid drink in H pylori positive subjects (24.1 (SEM 1.5)) was significantly higher than that obtained with any of the semiliquid meals (13.3 (SEM 1.1) and 17.1 (SEM 1.0) respectively, p < 0.001). Furthermore, this delta peak was obtained earlier with the citric acid drink (30 (SEM 2) minutes) than with the other two meals tests (53 (SEM 2) min and 45 (SEM 2) min, p < 0.001). The sensitivity of the 13C-UBT for the diagnosis of H pylori infection was 96-100% with all three test meals. This high sensitivity was, however, obtained from 15 minutes by giving citric acid as the test drink, from 45 minutes by giving a semiliquid fatty meal, and at 60 minutes by giving the semiliquid standard meal. The specificity was 100% for all test meals. Citric acid is inexpensive and palatable to patients. CONCLUSIONS: The 13C-UBT procedure with citric acid as the test drink is superior to the previously proposed semiliquid test meals in terms of 13CO2 recovery, time requirement, and cost. In routine clinical sampling, collection at times 0 and 30 minutes seems to be optimal and gives a high diagnostic accuracy.

Administration, Oral↗

PubMedDate not supplied

Effect of cisapride on gastric sensitivity to distension, gastric compliance and duodeno-gastric reflexes in healthy humans.

BACKGROUND AND AIMS: Visceral hypersensitivity and impaired gastric relaxation after the ingestion of a meal are frequent features in patients with functional dyspepsia. Cisapride improves dyspeptic symptoms. The study aims to evaluate whether cisapride influences gastric sensitivity to distension as well as gastric compliance and duodenogastric reflexes. PATIENTS AND METHODS: Eight healthy males were studied on two different days, each after 7 days' treatment either with placebo or cisapride 10 mg qid in randomized order. A spherical bag connected to a barostat was placed in the gastric fundus and an 8-lumen manometric catheter was positioned with 4 side holes in antrum and 4 in duodenum. During a phase II of the migrating motor complex, the intragastric bag was inflated at a constant pressure 1 mm Hg above the intra-abdominal pressure and the gastric volume was measured during intraduodenal infusion of lipids and citric acid at different rates. Once the stomach returned to the basal volume, the bag was distended according to two different protocols until subjects reported discomfort. Antroduodenal motility was measured throughout the study. RESULTS: Intraduodenal infusion of lipids and citric acid caused relaxation of gastric fundus. Relaxation was similar for lipids and acid (203 +/- 30 vs 199 +/- 43 ml), and was not influenced by cisapride and infusion rate. Cisapride did not influence gastric sensitivity to distension (10 +/- 1.5 vs 9.7 +/- 1.3 mm Hg) and gastric compliance (52.7 +/- 1.2 vs 49.8 +/- 1.8 ml/mm Hg). The antral motor index significantly decreased following infusion of acid and lipids with placebo but not with cisapride. CONCLUSIONS: Cisapride inhibits the physiological duodenoantral reflexes but does not influence either the mechanical properties of the gastric fundus nor the gastric sensitivity to distension.

Adult↗

PubMedDate not supplied

Novel strategies in the prevention of gastric cancer.

Helicobacter pylori has been classified as a human carcinogen contributing to the pathogenesis of gastric cancer. Eradication of H. pylori as a means towards preventing gastric cancers has become an interesting option, however, the scientific data supporting this practice are not well established. Therefore, large, multicenter trials have been initiated in order to assess and establish the scientific basis for this option. Reverting histomorphological and biochemical changes of the gastric mucosa after H. pylori eradication point to a beneficial effect of H. pylori eradication on the prevention of gastric cancers. This article will give a brief overview on the current knowledge on the pathogenesis of gastric cancer and the role of H. pylori in this regard and will also describe current approaches towards preventing gastric cancer.

Animals↗