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RE: Helicobacter pylori



The following selected references (by no means is this a complete list) may
help some of you understand what this is all about.  It is somewhat
entertaining to watch non-physician health physicists speculate about the
merits of a diagnostic test that involves a substance they have been taught (or
have been teaching) is of great danger!!

Barry A. Siegel, M.D.
Division of Nuclear Medicine
Mallinckrodt Institute of Radiology
510 S. Kingshighway Blvd.
St. Louis, MO 63110
PHONE:  (314) 362-2809
FAX:  (314) 362-2806
INTERNET:  siegelb@mirlink.wustl.edu
********************************************************************************

1
AU  - Raju GS
AU  - Smith MJ
AU  - Morton D
AU  - Bardhan KD
TI  - Mini-dose (1-microCi) 14C-urea breath test for the detection of
      Helicobacter pylori.
SO  - Am J Gastroenterol 1994 Jul;89(7):1027-31
AB  - OBJECTIVES: To develop and evaluate a mini-dose (1-microCi) 14C-urea
      breath test (UBT), using a simplified protocol. METHODS: Fasting
      patients (n = 95) were given a drink of 1 microCi (37 kBq) of
      14C-urea. Samples of breath carbon dioxide (2 mmol) were collected
      at 10, 20, and 30 min later by trapping in hyamine solution; 14C
      activity was measured by liquid scintillation counting. Results were
      expressed as "CO2 recovery," i.e., [(% of administered dose
      recovered/mmol CO2 trapped) x body weight (kg)]. Reproducibility of
      the test was assessed by repeat studies on two consecutive days in
      11 volunteers. All breath test results were compared with culture
      for Helicobacter pylori. In 27 patients, results also were compared
      with 13C-urea breath test (European protocol). RESULTS: Using
      receiver operator characteristic (ROC) analysis, we selected a
      cut-off value of 0.55 at 20 min to separate those positive and
      negative for H. pylori. Sensitivity and specificity were 98% and
      87%, respectively. Among four patients with negative culture but
      positive 14C-breath tests, three had evidence of infection by
      serology or 13C-UBT. Assuming that these three were genuinely
      positive, the recalculated specificity improved to 97%, sensitivity
      remaining at 98%. The reproducibility of the test was good, with
      only a minor day-to-day variation. Concordance with the 13C-UBT was
      excellent: there was 100% agreement in the diagnostic classification
      of all 27 patients (19 positive, eight negative). CONCLUSIONS: The
      mini-dose 14C-urea breath test has a high diagnostic accuracy
      (sensitivity 98%, specificity 97%) with minimal radiation exposure.
      It is simple, rapid, and convenient for a busy general hospital.

2
AU  - Kao CH
AU  - Huang CK
AU  - Wang SJ
AU  - Hsu CY
AU  - Lin WY
AU  - Chen GH
TI  - Accuracy of a rapid 10-minute carbon-14 urea breath test for the
      diagnosis of Helicobacter pylori-associated peptic ulcer disease.
SO  - Eur J Nucl Med 1993 Aug;20(8):708-11
AB  - Urease in the human gastric mucosa is a marker for infection with
      Helicobacter pylori (HP), an organism which is associated with
      peptic ulcer disease. To detect gastric urease, we examined 184
      patients (144 males, 40 females; mean age: 49.8 +/- 15.6 years) with
      suspected peptic ulcer disease. Fasting patients were given orally 5
      microCi of carbon-14 labelled urea. From each patient only one
      breath sample was collected in hyamine at 10 min. The amount of 14C
      collected at 10 min was expressed as follows: [(DPM/mmol CO2
      collected)/(DPM administered)] x 100 x body weight (kg). The
      presence of HP colonization was determined by examination of
      multiple endoscopic prepyloric antral biopsy specimens subjected to
      culture or a rapid urease test. For the purpose of this study,
      HP-positive patients were defined as those with characteristic
      bacteria as indicated by a positive result of either the culture or
      the rapid urease test; HP-negative patients were defined as those
      with negative findings on both the culture and the rapid urease
      test. Of the 184 cases, 99 (53.8%) were positive for HP infection,
      and 85 (46.2%), negative. The sensitivity and specificity of the
      rapid 10 min 14C-urea breath test for the diagnosis of HP-associated
      peptic ulcer disease were evaluated by a receiver operating
      characteristic (ROC) curve with a variable cut-off value from 1.5 to
      4.5. When a cut-off value of 1.5 was selected, the sensitivity was
      100% and the specificity, 83.5%; when a cut-off value of 4.5 was
      selected, the sensitivity was 54.5% and the specificity, 97.6%.

3
AU  - Atherton JC
AU  - Spiller RC
TI  - The urea breath test for Helicobacter pylori. [Review]
SO  - Gut 1994 Jun;35(6):723-5

4
AU  - Stubbs JB
AU  - Marshall BJ
TI  - Radiation dose estimates for the carbon-14-labeled urea breath test.
SO  - J Nucl Med 1993 May;34(5):821-5
AB  - The use of the 14C-urea breath test for diagnosis of Helicobacter
      pylori infection in gastric mucosa has gained widespread acceptance
      and utilization. In order to obtain regulatory approval for this
      procedure, new dose estimates were required. Previous radiation dose
      equivalent estimates for males only were based upon data published
      in 1975 for bicarbonate metabolism. Since that time, calculational
      techniques for dose estimation have been significantly improved and
      the organ masses of Reference Man updated. We have calculated dose
      estimates for males and females who test positive (HP+) and negative
      (HP-) for gastric H. pylori infection. Our results indicate that the
      urinary bladder wall receives the highest absorbed dose in all four
      of the above subject populations (HP- males = 0.14 mGy/MBq; HP-
      females = 0.19 mGy/MBq; HP+ males = 0.10 mGy/MBq; HP+ females = 0.14
      mGy/MBq). Gonadal absorbed doses were similar to those previously
      estimated (testes < 0.065 mGy/MBq and ovaries < 0.084 mGy/MBq,
      respectively).

5
AU  - Munster DJ
AU  - Chapman BA
AU  - Burt MJ
AU  - Dobbs BR
AU  - Allardyce RA
AU  - Bagshaw PF
AU  - Troughton WD
AU  - Cook HB
TI  - The fate of ingested 14C-urea in the urea breath test for
      Helicobacter pylori infection.
SO  - Scand J Gastroenterol 1993 Aug;28(8):661-6
AB  - The metabolic fate of the radioactive carbon in the 14C-urea breath
      test for Helicobacter pylori was investigated in 18 subjects. After
      ingestion of labelled urea, breath was sampled for 24 h, and urine
      was collected for 3 days. Subjects were designated high or low
      expirers on the basis of their breath counts, and this agreed well
      with H. pylori serologic analyses. When given 185 or 37 kBq of
      14C-urea, 51% (SD = 16%, n = 11) of the label was recovered from the
      breath of high expirers, and 7% (SD = 3%, n = 7) from the breath of
      low expirers. The mean combined urinary and breath recovery for high
      expirers was 86% (SD = 7%), and for low expirers it was 97% (SD =
      3%). It is concluded that the long-term retention of 14C from
      ingested 14C-urea is low. The results enable a more accurate
      estimation to be made of radiation exposure resulting from the
      14C-urea breath test.

6
AU  - Henze E
AU  - Malfertheiner P
AU  - Clausen M
AU  - Burkhardt H
AU  - Adam WE
TI  - Validation of a simplified carbon-14-urea breath test for routine
      use for detecting Helicobacter [correction of Heliobacter] pylori
      noninvasively.
SO  - J Nucl Med 1990 Dec;31(12):1940-4
AB  - A carbon-14 (14C) urea breath test for detecting Helicobacter pylori
      with multiple breath sampling was developed. Carbon-14-urea (110
      kBq) administered orally to 18 normal subjects and to 82 patients
      with Helicobacter infection. The exhaled 14C-labeled CO2 was trapped
      at 10-min intervals for 90 min. The total 14C activity exhaled over
      90 min was integrated and expressed in %activity of the total dose
      given. In normals, a mean of 0.59% +/- 0.24% was measured, resulting
      in an upper limit of normal of 1.07%. In 82 patients, a sensitivity
      of 90.2%, a specificity of 83.8%, and a positive predictive value of
      90.2% was found. The single probes at intervals of 40-60 min
      correlated best with the integrated result, with r ranging from
      0.986 to 0.990. The test's diagnostic accuracy did not change at all
      when reevaluated with the 40-, 50-, or 60-min sample data alone.
      Thus, the 14C-urea breath test can be applied routinely as a
      noninvasive, low-cost and one-sample test with high diagnostic
      accuracy in detecting Helicobacter pylori colonization.