Stable isotope techniques for the detection of Helicobacter pylori infection in clinical practice. 13C-urea breath test in different experimental conditions

The (13)C-UBT has been demonstrated to be a reliable method for the evaluation of Helicobacter pylori infection. The aim of our work is to determine the cut-off point of the (13)C-UBT for samples collected as gas or collected in a solution of triethanolamine. For this purpose, patients fasted for at least 6 hours were able to collect basal samples before the administration of 65 mg of (13)C-urea solution. Breath samples were taken 10,30 and 60 minutes after the administration of the labeled solution. All the samples were collected in gas collectors and in glass vials containing 1 ml of a 7 per cent triethanolamine solution. The cut-off points for gas collected samples were established in 4.0 per cent and for 10, 30 and 60 minutes samples, respectively, while for the samples, collected in triethanolamine solution, cut-off points were established in 5.0 per cent, for the 10 minutes samples, in 3.5 per cent for the 30 minutes samples and 4.7 per cent for the 60 minutes samples. We found that this test has a sensitivity of 100 per cent and a specificity of 100 per cent for H. pylori detection in both experimental conditions, when multiple breath samples are taken. If we considered only the 30 minutes time, sensitivity and specificity diminish for the gas collected samples. We conclude that the collection of breath samples in triethanolamine solution allows a better differentiation between H. pylori infected and non infected patients than gas collected samples.

El sistema surfactante pulmonar: fisiología, patologías asociadas a su alteración y administración exógena como agente terapéutico y de diagnóstico / The pulmonary surfactant system: physiology, associated pathologies the its alteration and exogenous administration as therapeutic and diagnostic agent

El surfactante pulmonar es una mezcla lipoproteica sintetizada y secretada por las células alveolares pulmonares tipo II. Su principal función es la disminución de la tensión superficial formando una monocapa en la superficie alveolar. Su deficiencia es el principal factor asociado al síndrome de dificultad respiratoria del recién nacido (RDS) y al síndrome de dificultad respiratoria del adulto (ARDS). Desde 1980 se está estudiando la administración exógena del surfactante pulmonar para el tratamiento de estos dos síndromes. En este trabajo se describen los surfactantes exógenos disponibles para uso clínico, las técnicas de administración y el esquema de dosificación. La utilización del surfactante natural exógeno (ENS) marcado con (99m)Tc((99m)Tc-ENS) para su utilización como radiofármaco en centellografía aérea pulmonar también es descripta en este trabajo.