Application of isotope-selective non-dispersive infrared spectrometry for the evaluation of the 13C-urea breath test: comparison with three concordant methods

The aim of this work was to compare the performance of isotope-selective non-dispersive infrared spectrometry (IRIS) for the 13C-urea breath test with the combination of the 14C-urea breath test (14C-UBT), urease test and histologic examination for the diagnosis of H. pylori (HP) infection. Fifty-three duodenal ulcer patients were studied. All patients were submitted to gastroscopy to detect HP by the urease test, histologic examination and 14C-UBT. To be included in the study the results of the 3 tests had to be concordant. Within one month after admission to the study the patients were submitted to IRIS with breath samples collected before and 30 min after the ingestion of 75 mg 13C-urea dissolved in 200 ml of orange juice. The samples were mailed and analyzed 11.5 (4-21) days after collection. Data were analyzed statistically by the chi-square and Mann-Whitney test and by the Spearman correlation coefficient. Twenty-six patients were HP positive and 27 negative. There was 100% agreement between the IRIS results and the HP status determined by the other three methods. Using a cutoff value of delta-over-baseline (DOB) above 4.0 the IRIS showed a mean value of 19.38 (minimum = 4.2, maximum = 41.3, SD = 10.9) for HP-positive patients and a mean value of 0.88 (minimum = 0.10, maximum = 2.5, SD = 0.71) for negative patients. Using a cutoff value corresponding to 0.800% CO2/weight (kg), the 14C-UBT showed a mean value of 2.78 (minimum = 0.89, maximum = 5.22, SD = 1.18) in HP-positive patients. HP-negative patients showed a mean value of 0.37 (minimum = 0.13, maximum = 0.77, SD = 0.17). IRIS is a low-cost, easy to manage, highly sensitive and specific test for H. pylori detection. Storing and mailing the samples did not interfere with the performance of the test.

Helicobacter pylori in South America

Helicobacter pylori is the most common chronic bacterial infection in humans. In less developed nations, e.g., most South American countries, the prevalence of H pylori infection ranges from 70% to 90% of the population. In these countries there is rapid acquisition of the infection in early life, due to poor sanitation, low standards of living conditions and an increased rate of H pylori infection. The management of H pylori infection in South America is outlined.

Histology of the mucosa of gastric antrum and body before and after eradication of Helicobacter pylori

1. Helicobacter pylori status and the histology of the antral and oxyntic mucosa were evaluated in 25 patients with duodenal ulcer treated with a triple schedule of furazolidone, metronidazole and amoxicillin, and in 16 patients treated only with cimetidine. 2. Before treatment, H. pylori was detected in all patients. One month after treatment with the antimicrobial agents, H. pylori was not found in 18 (72.0%) of 25 patients treated with the triple schedule. In the patients treated with cimetidine (N = 16) the H. pylori tests continued to be positive after treatment. 3. Inflammatory activity and intensity of gastritis were significantly reduced in patients treated with the antimicrobial agents but not in cimetidine-treated patients. Three patients who had negative cultures and improvement of gastritis 1 month after treatment became H. pylori positive again within 2 months, with concomitant reappearance of gastritis. 4. This study provides additional evidence that histological gastritis observed in H. pylori-positive patients with duodenal ulcer is due to the presence of the microorganism.

Effect of Helicobacter pylori eradication on antral gastrin- and somatostatin-immunoreactive cell density and gastrin and somatostatin concentrations

The density of antral gastrin (G)- and somatostatin (D)-immunoreactive cells and the contents of antral gastrin and somatostatin were investigated in endoscopic antral biopsy specimens from patients with duodenal ulcer before and after eradication of Helicobacter pylori. After H. pylori eradication both antral somatostatin concentration (p = 0.0002) and antral D-cell density (p = 0.01) increased significantly. Conversely, although the number of G-cells was unchanged, antral (p = 0.0002) and serum (p = 0.001) gastrin contents decreased significantly. The number of oxyntic D-cells did not change significantly. These results strongly suggest that the hypergastrinaemia observed in H. pylori-positive patients may be due to a deficiency in antral somatostatin, which normally inhibits the synthesis and release of gastrin.

Histamine content of the oxyntic mucosa from duodenal ulcer patients: effect of Helicobacter pylori eradication

The histamine concentration of the oxyntic mucosa was determined in Helicobacter pylori-positive patients with duodenal ulcer before and after antimicrobial therapy and in H. pylori-negative subjects. Determination of serum gastrin was also performed in duodenal ulcer patients before and after H. pylori eradication. The histamine content of the oxyntic mucosa was lower in patients with duodenal ulcer than in H. pylori-negative subjects, but it increased after H. pylori eradication. Conversely, in patients in whom therapy failed to eradicate the microorganism, the histamine content remained unchanged. Serum gastrin levels fell after microorganism eradication, and the percentage of this fall was correlated with the percentage of increase in gastric histamine. In conclusion, our findings suggest that abnormalities of histamine store present in duodenal ulcer patients might be a feature of H. pylori infection.

Comparison of the urease test and of direct smear examination in the control of treatment of Helicobacter pylori-induced infection

The sensitivity and specificity of the preformed urease test and of carbolfuchsin-stained smears for the diagnosis of the presence of Helicobacter pylori in gastric mucosa were evaluated before and after antimicrobial treatment. The results obtained by culture were used as the reference point. We studied 41 patients with endoscopically diagnosed duodenal ulcer. Twenty-five of these were treated with furazolidone (100 mg t.i.d.), amoxicillin (500 mg t.i.d.) and metronidazole (250 mg t.i.d.) for 5 days and then with only furazolidone (100 mg t.i.d.) for an additional 25 days. The 16 control patients were treated with cimetidine (800 mg, 4 times a day). The sensitivity of the urease test and of direct smear examination was 100% before treatment and 84.6% and 92.3%, respectively, after treatment. We conclude that the urease test and carbolfuchsin-stained smears, which are highly sensitive for H. pylori diagnosis, present reduced sensitivity when they are employed for the follow-up of patients treated with antimicrobials.

Duodenal ulcer and eradication of Helicobacter pylori in a developing country. An 18-month follow-up study

Forty-eight patients with endoscopically proven duodenal ulcer (DU) and Helicobacter pylori infection detected by 14C-urea breath test (BT) were assigned to 5 days of treatment with furazolidone, metronidazole, and amoxicillin in addition to eventual classical anti-ulcer agents if necessary. Clinical evaluation and BT were repeated at 2, 6, and 18 months after therapy to determine H. pylori eradication or reinfection. Endoscopy was also repeated at 6 and 18 months after treatment to detect DU relapse. In 29 (60%) patients H. pylori had been eradicated at 2 months after therapy, and in 19 (40%) infection persisted. After successful eradication, 6 of 29 (20.7%) were reinfected. All 24 patients who were negative at the 18-month evaluation were asymptomatic, free of anti-ulcer drugs, and with healed ulcers, whereas among the 19 positive patients followed up, 11 (57%) continued to be symptomatic and still using anti-ulcer agents (p less than 0.010), and 10 (53%) showed active ulcers at endoscopy (p less than 0.010). H. pylori eradication is clearly followed by long-term remission of DU. Reinfection may be an additional problem in treating DU patients in developing countries.

Five-day bismuth-free triple therapy for the eradication of Helicobacter pylori and reduction of duodenal ulcer relapse

Previous studies have demonstrated that the eradication of Helicobacter pylori (H. pylori) is associated with a significant reduction of the rate of duodenal ulcer (DU) relapse. The aim of this study was to assess the long-term effect of a bismuth-free triple therapy on the eradication of H. pylori and reduction of DU relapse. After informed consent, 61 patients with endoscopically proven DU and H. pylori infection detected on 14C-urea breath test (BT) were included in the study. All patients received a combination of furazolidone, amoxicillin, and metronidazole, three times a day, for 5 days, in addition to eventual classical antiulcer agents prescribed by their attending physicians. BT was repeated after an interval of at least 60 days to evaluate H. pylori eradication. Endoscopy and another BT were performed again at 6.5 months after therapy to detect possible recurrences. Forty-eight patients completed the trial: 26 (54%) patients were negative for H. pylori at 6.5 months after the end of treatment, and 22 (46%) persisted H. pylori positive. Ninety-two percent of the patients in whom the bacteria were eradicated showed endoscopically healed ulcers and were asymptomatic, and two that were symptomatic presented only occasional pain not requiring therapy. Among the 22 patients who persisted H. pylori positive, six (27%) showed endoscopically active ulcers (p = 0.012) and eight (36%) patients continued to be symptomatic (p less than 0.01), and were still using antiulcer drugs (p = 0.002) 6.5 months after treatment. It is concluded that combined treatment with furazolidone, amoxicillin, and metronidazole for 5 days represents a well-tolerated, inexpensive, and effective therapeutic regime for the eradication of H. pylori and abolition of DU relapse in more than 50% of the patients during a follow-up period of 6.5 months.

[Furazolidone and cimetidine in patients with active duodenal ulcer and Helicobacter pylori in the gastric antrum]

In order to assess the effect of furazolidone on duodenal ulcer disease and Helicobacter pylori (Hp), a double-blind, double-dummy, randomized, prospective pilot study comparing furazolidone and cimetidine was carried out in 31 antral Hp positive patients with endoscopically proven active duodenal ulcer. Clinical, endoscopical, bacteriological and histological studies were done before and at four weeks of the study in all patients. If the ulcer was not healed, the treatment was extended for a further four weeks and all the procedures repeated. The healed ulcer patients were followed-up and re-endoscoped, regardless the presence of symptomatology, at least at 3 and 6mo after the end of treatment. It was observed that furazolidone cleared Hp (18% x 0%), healed the ulcer (91% x 87%) and reduced the relapse rate (30% x 92%; p < 0.025).

Campylobacter pylori in esophagus, antrum, and duodenum. A histological and microbiological study

Two hundred forty-six patients with a wide range of upper gastrointestinal tract disorders were investigated for the presence of Campylobacter pylori infection in esophagus, gastric antrum, and duodenum. C. pylori was identified in 52% of patients in at least one site, and microbiological and histological techniques were used to exclude the presence of the organism. Esophageal infection was not significant and is probably due to reflux. Antral C. pylori was significantly associated with active gastritis and active duodenitis and is possibly pathogenic.

Rapid diagnosis of Campylobacter pyloridis infection

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Campylobacter pyloridis in the upper gastrointestinal tract: a Brazilian study

The successful isolation of C. pyloridis from human gastric mucosa has renewed interest in these bacteria and their role as a causative agent for gastritis, and possible causal relationship between chronic gastritis and peptic ulceration. To determine the incidence of C. pyloridis in gastric biopsies we studied 51 consecutive Brazilian patients with a wide range of alimentary disorders presenting for endoscopy. At least three biopsies were taken from each site: antrum, any ulcer or cancer. Microbiological and histological studies were performed to identify the bacteria. The organism was found in 40/51 (78%) of patients. These was a close correlation between culture (100%), Gram (90%) and Gimenez staining (80%) in identifying the bacteria. All C. pyloridis positive patients had histological evidence of antral chronic gastritis (active or quiescent) even if the endoscopic appearance looked normal. All peptic ulcer patients (n = 17) showed C. pyloridis in the antrum. In the duodenum the bacteria were mainly seen in gastric type of mucosa. Our findings support the hypothesis that C. pyloridis is etiologically related to gastritis and possibly peptic ulceration.

[Effect of an antacid containing calcium on gastric acid secretion, in patients with duodenal ulcer]

In eight fasting men with duodenal ulcer disease, oral administration of therapeutic dose of 49,5 mEq of neutralizing potency of either sodium bicarbonate or a preparation of calcium hidroxogluconaluminate did not produce significant increase in gastric acid secretion above basal levels for 90 minutes. This data support the conclusion that this specific antacid-containing calcium preparation does not stimulate the gastric secretion of acid.

[Effect of various therapeutic schedules of antacids on the pH of gastric contents in patients with duodenal ulcer]

Ten patients with uncomplicated duodenal ulcer were given three different therapeutic regimens of antacid experiments II, III and IV, and a control regimen, without antacid, named experiment I. Experiment I consisted of a normal diet with three meals a day; experiment II, III and IV consisted of a diet as in experiment I plus 132,06 mEq, 265,92 mEq or 396,88 mEq respectively of antacid divided in six equal doses given one and three hours after breakfast, lunch and dinner. Having been carefully instructed, the patients were intubated with a gastric tube, which was kept in for five days, receiving in each day one of the aforementioned regimens, in a sequential order. The fifth day was reserved for the augmented Histalog test. Each hour from 8 a.m. to 10 p.m., in the first four days, a sample of the gastric juice was aspirated for pH measurement. The statistical evaluation of the acidity of the samples at different times showed that experiment III (265,92 mEq antacid/day) was able to keep the pH over 3 for longer periods of time when compared with experiments I and II and not different from experiment IV. The present investigation emphasize the necessity of clinical trials comparing therapeutic regimens of antacid with different neutralizing capacity, in order to find the most effective dose in the treatment of duodenal ulcer.