The 14C-urea breath-test for the detection of gastric Campylobacter pylori infection.

A breath-test has been developed for the detection of gastric infection with Campylobacter pylori. Urea that is labelled with carbon 14 is administered to a fasting patient and the patient's breath is sampled for radioactivity over the following 30 minutes. If C. pylori is present in the patient's stomach, urease activity causes hydrolysis of the urea and the 14C is absorbed as carbon dioxide. This carbon dioxide enters the patient's bicarbonate pool and eventually is excreted in the breath. The results are expressed as a percentage of the administered dose/mmol carbon dioxide x kg body weight. Sixty-three patients who were undergoing endoscopy were studied. The radioactivity in exhaled breath which was sampled within five minutes of 14C-urea administration was attributed to the presence of urease enzyme in mouth organisms and was discounted. The time-radioactivity curves for breath samples from five to 30 minutes after the administration of 14C-urea gave an excellent separation between subjects with negative results of the examination of gastric-biopsy samples and patients with microbiological and histological evidence of infection with C. pylori. The area under the time-radioactivity curve at between five and 30 minutes after the administration of 14C-urea in 24 patients with negative microbiological results was 6.9 +/- 4.4 area units; in 35 of 39 patients with positive microbiological results, this area was greater than 40 area units. Measured against the results of the microbiological examination of gastric-biopsy samples, the sensitivity of breath-testing was 90% and the specificity was 100%. Measured against the results of histological examination for the presence of C. pylori infection, breath-testing had a sensitivity of 94% and a specificity of 93%. A positive breath-test result also correlated well (P = 0.0001) with the serological antibody test-result. The role of non-invasive tests--enzyme-linked immunosorbent assays and 14C-urea breath-testing--in the management of gastritis and peptic ulcer disease is discussed. We consider that the 14C-urea breath-test has an important role in the noninvasive confirmation of gastric infection with C. pylori and in the follow-up of patients after treatment.

Adjuvant BCG immunotherapy for stage I and II malignant melanoma.

Initial adjuvant immunotherapy trials have demonstrated a greater disease-free interval in patients treated with bacille Calmette-Guérin (BCG) compared with historical controls. In this study 149 patients at high risk of recurrence after surgical treatment of local or regional malignant melanoma were given BCG for 2 years and were followed up for a median of 28 months from the start of immunotherapy. The 36 patients in the comparison group had a higher rate of recurrence than the patients treated with BCG, and the rate in the treatment group was close to that reported from a similar study at the University of California at Los Angeles. The relatively long disease-free interval for the high-risk comparison patients in this study suggests that the control groups at other centres may have included patients with unrecognized additional risk. The rates of survival in the Canadian treatment group were also comparable to those reported by other centres. However, reports of a favourable BCG-mediated pattern of recurrence could not be confirmed. Therefore, the routine use of adjuvant BCG immunotherapy is not recommended.

Prediction of malignant melanoma recurrence by serum N-acetylneuraminic acid.

Since serum N-acetylneuraminic acid (NANA) can serve as a relatively sensitive monitor of tumor burden, we wished to examine the relationship of NANA to other suggested prognostic factors for malignant melanoma. Eligible patients included 151 patients with stage-I disease and 10 with stage-II regional lymphatic extension. A proportional hazards model was used to examine nine factors, of which five were not significant predictors of recurrence: age, sex, primary site, tumor diameter, and stage. Significant predictors included: measured depth p = 7 X 10(-7); anatomic depth (Clark level), p = 7 X 10(-6); NANA, p = 0.003; and growth pattern (superficial spreading vs nodular), p = 0.01. However, on multivariate analysis only two predictors were independent; measured depth and NANA. The latter could not be explained by non-specific factors. The data were examined to define optimal test values for assignment of risk. According to this model, patients with lesions greater than 1.75 mm and NANA less than 2 mumol/ml have a more than 12-fold greater risk of recurrence by 2 years than those with lesions less than or equal to 1.75 mm and NANA less than or equal to 2 mumol/ml.

P3 amylase isoenzyme in patients with cholelithiasis.

The plasma P3 amylase isoenzyme was determined in 25 patients with proven cholelithiasis. In six patients who had a single gallstone and normal pancreas at operation, the total plasma amylase was within normal limits and the P3 amylase isoenzyme was absent. In the remaining 19 patients who had multiple gallstones, pancreatitis was found at surgery in 10. In this group of 10 patients, the total plasma amylase was above the reference range for healthy individuals in only five (50%), while the P3 amylase isoenzyme band was detected in all 10 (100%). It is concluded that P3 amylase isoenzyme is superior to the total plasma amylase in the diagnosis of pancreatitis in patients with gallstone.