ABSTRACT
The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests. We have developed a 14C-urea breath test which uses 5 microCi 14C with 50 mg nonradioactive urea. Breath samples are collected at baseline and every 30 min for 2 h. Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients. The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positive predictive value 93%, and negative predictive value 100%. Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled 14CO2 which correlated with histological improvement in gastritis. The 14C-urea breath test is a better "gold standard" for the detection of Helicobacter pylori than histology and/or culture.
Subject(s)
Breath Tests , Campylobacter Infections/diagnosis , Urea , Biopsy , Campylobacter/isolation & purification , Campylobacter Infections/epidemiology , Carbon Radioisotopes , Gastric Mucosa/microbiology , Humans , Predictive Value of TestsABSTRACT
The Iodogen technique was compared with the microelectrochemical technique for the radioiodination of submilligram quantities of monoclonal antibody 140.240. The titre of the antibody against cultured melanoma cells was decreased five-fold after iodination with 0.80-0.85 atoms of iodine per molecule of antibody with both techniques. The Iodogen technique resulted in 82.1% incorporation of iodine into the antibody, somewhat higher than the 78.0% obtained with the microchemical technique (P = 0.10). Therefore, the Iodogen technique is the preferred method based on efficiency and convenience.
Subject(s)
Antibodies, Monoclonal , Iodine Radioisotopes , Isotope Labeling/methods , Urea/analogs & derivatives , Electrochemistry , Indicators and ReagentsABSTRACT
A subacute toxicity study on 99m Tc stannous glucoheptonate was performed with rats, dogs and rabbits, injected intravenously at ten to 100 times the human dose on a body weight basis. There were no abnormalities in the clinical status of any of the animals. No changes were found in urinalysis, blood chemistry or hematology in the rabbit nor in gross examination, renal histology or bone marrow smears in the rats and rabbits. Hepatic histology was also done. A focal area of necrosis in a liver of one rabbit that had been injected with 100 times the human dose was observed using light microscopy. Examination by electron microscopy in another group of rats and rabbits was prompted by the observation of that lesion. This revealed vacuolated and dilated smooth endoplasmic reticulum and degranulated and vesiculated rough endoplasmic reticulum in all the test livers. X-ray microanalysis indicates that the ultrastructural changes are linked to the deposition of tin.
Subject(s)
Organotechnetium Compounds , Sugar Acids/toxicity , Technetium/toxicity , Tin Compounds , Tin/toxicity , Animals , Dogs , Injections, Intravenous , Liver/ultrastructure , Muridae , Necrosis , Rabbits , Sugar Acids/administration & dosage , Technetium/administration & dosage , Tin/administration & dosageABSTRACT
We describe an investigation of the stability of Tc-99m pyrophosphate (Tc-99m PPi). We hve shown that addition of exogenous hydrogen peroxide to Tc-99m PPi can initiate the oxidation of the complex, giving rise to 95% unbound pertechnetate. The presence of endogenous hydrogen peroxide in the sodium pertechnetate used in the preparation of Tc-99m PPi has been thought to influence its stability. We have prepared it using pertechnetate solutions of different specific activities. After preparation, an alumina column was used to detect free 99mTcO4-. The Tc-99m PPi and Na99mTcO4 solutions were then assayed by iodometric titration for hydrogen peroxide, which was detected in the pertechnetate solutions. The higher the specific activity of the solution used for the tracer preparation, the faster was the production of free pertechnetate.
Subject(s)
Diphosphates , Hydrogen Peroxide , Technetium , Drug Stability , Sodium Pertechnetate Tc 99m , Technetium Tc 99m PyrophosphateSubject(s)
Femoral Fractures/diagnostic imaging , Iodine Radioisotopes , Tetracyclines , Bone Nails , Bone and Bones/metabolism , Femoral Fractures/metabolism , Femoral Fractures/surgery , Fracture Fixation, Internal , Humans , Radionuclide Imaging , Tetracycline/metabolism , Time Factors , Tissue Distribution , Wound HealingABSTRACT
A thoretical consideration of the factors which influence the accumulation of radiopharmaceuticals in bone is presented. The avidity with which 99mTc-Sn-pyrophosphate and 18F fluoride are adsorbed by bone crystals has been measured in vitro and the efficiency with which these radiopharmaceuticals are extracted by normal bone has been measured in vivo. It is postulated that alterations in the capillary permeability in the region of a bone lesion greatly influence the target to background ratio that can be obtained with bone seeking radiopharmaceuticals. Quantitiated gamma camera studies in man are presented in support of this hypothesis.
Subject(s)
Bone Diseases/diagnosis , Diphosphates , Fluorine , Radionuclide Imaging , Technetium , Animals , Humans , Rabbits , RadioisotopesABSTRACT
The preparation of an yttrium-90 citrate colloid is described. This formulation localizes in the synovial membrane and thereby eliminates any irradiation received by extra-articular tissues. Yttrium-90 is eluted from Sr-90 bound to a sulphonic acid ion exchange resin. The colloid is prepared using a 3:1 ratio of carrier yttrium and citrate. Contamination with ionic 90Y and ionic 90Sr was less than 1 percent and 0.001 percent, respectively. In the 28 patients studied, all of the injected dose of 90Y remained in the region of the joint. Brief clinical results are presented.
Subject(s)
Arthritis, Rheumatoid/radiotherapy , Citrates , Colloids/chemical synthesis , Radiation Effects , Synovial Membrane/radiation effects , Yttrium Radioisotopes/therapeutic use , Animals , Citrates/metabolism , Humans , Injections, Intra-Articular , Rabbits , Synovial Membrane/metabolism , Time Factors , Yttrium Radioisotopes/administration & dosage , Yttrium Radioisotopes/metabolismABSTRACT
Comparative in vivo absorption of cyanocobalamin from two dosage forms, gelatin capsule and liquid, was studied. Forty-two subjects received simultaneous doses of cyanocobalamin in capsule and liquid form, labeled with cobalt-57 and cobalt-60, respectively. Excretion, a measure of absorption, was between 2 percent and 66 percent greater with the liquid form. In vitro dissolution studies showed that the capsules had a tendency to collapse into a stringy mass and to dissolve slowly.
