ABSTRACT
Objective To optimize the measurement and analysis method for carbon-14 in environmental biological samples, and to provide technical support for the formulation of standard methods for carbon-14 measurement in environmental biological samples. Methods Through the optimization research on the carbon dioxide absorption method, the moisture content and carbon content of biological samples were measured with the moisture meter and the element analyzer according to the simplified personnel operation and the optimized process steps of the method, and intra- and inter-laboratory validation of the method was carried out. Results Under typical conditions, the lower limit of detection of the method reached 3 Bq/kg, and there were a relative standard deviation within laboratories of less than 17% and a relative standard deviation between laboratories of less than 14%, with a relative error of less than 19%. Most of the sample pretreatment was directly completed by the instrument and equipment, which improved the precision and accuracy of the measurement of moisture content and carbon content in samples, and reduced the influence of experiment personnel’s operation differences on the test results. Conclusion The lower limit of detection, precision, and accuracy of the optimized method meet the relevant requirements for the determination of carbon-14 in biological samples.
ABSTRACT
siendo el test de aliento con urea carbono-14 (C-14) uno de los métodos de diagnóstico no invasivos; sin embar-go, no ha sido comprobada su utilidad en la población ecuatoriana.Objetivo: Evaluar la sensibilidad y especificidad del test de aliento con urea C-14 para predecir la infección por HP en la población ecuatoriana.Métodos: Estudio de Pruebas Diagnósticas realizado en pacientes que acudieron a la consulta externa del servicio de gastroenterología del Hospital Teófilo Dávila de la ciudad de Machala, en el periodo abril 2018 a marzo 2019. Los pacientes se sometieron a una endoscopia superior de luz blanca (ES) con toma de biopsias para investigar la infec-ción por HP; además, se realizó un test de aliento con urea C-14, para compararla con los resultados de las biopsias.Resultados: Se estudiaron 78 pacientes con una edad media de 33.76±11.2 años. El diagnóstico de gastritis se confirmó a través de la ES e histopatología en el 100% de los pacientes. El test de aliento con urea C-14 fue positi-va en 47/78 (60.3%) pacientes. Se demostró evidencia de infección por HP en biopsias gástricas de 50/78 (64.1%) pacientes. La sensibilidad, especificidad, VPP, VPN, observada y la concordancia entre evaluadores fue de 94%, 100%, 100%, 90%, 96% y 92% (P <0.001), respectivamente.Conclusiones: El test de aliento con urea C-14, es una herramienta útil para predecir infección por HP en la población ecuatoriana
Background: Early detection of Helicobacter pylori infection has become more relevant, with urea carbon-14 (C-14) breath test as one of the non-invasive diagnostic methods; however, it has not been proven in Ecuadorian population.Objective: To evaluate the sensitivity and specificity of the C-14 urea breath test to predict HP infection in the Ecuadorian population.Methods: : Study of diagnostic tests performed on patients who attended the outpatient gastroenterology service of the Hospital Teófilo Dávila in the city of Machala, in the period April 2018 to March 2019. The patients underwent an upper endoscopy of white light (WLE) with biopsies taken to investigate HP infection. In addition, a breath test with C-14 urea was performed to compare it with the biopsies results.Results: 78 patients with a mean age of 33.76±11.2 years were studied. The diagnosis of gastritis was confirmed through endoscopy and histopathology in 100% of the patients. The breath test with urea C-14 was positive in 47/78 (60.3%) patients. Evidence of HP infection was demonstrated in gastric biopsies from 50/78 (64.1%) pa-tients. Sensitivity, specificity, PPV, NPV, and inter-rater reliability were 94%, 100%, 100%, 90%, 96%, and 92% (P <0.001), respectively.Conclusions: The C-14 urea breath test is a useful tool for predicting HP infection in the Ecuadorian population
Subject(s)
Humans , Adult , Urease , Helicobacter pylori , Diagnostic Techniques, Digestive System , Biopsy , Carbon Radioisotopes , Ecuador , EndoscopyABSTRACT
Background: The most common human infection of upper gastrointestinal region is Helicobacter pylori. Most individuals remain asymptomatic due to misuse of antibiotic and proton pump inhibitors. Methods: 50 patients admitted or on outpatient department basis were selected based on the upper gastrointestinal symptoms and whether they were 18 years and above. Results: The Rapid Urease Test (RUT) had 84% sensitivity and 91% specificity, with an overall accuracy of 88%. The results of the Urea breath Test (UBT) showed 88% sensitivity and 83% specificity, and an overall accuracy of 85%. Conclusions: The invasive procedure OGD scopy need not be done in patients for the sole purpose of diagnosing HP infection as the diagnostic efficacies of RUT & UBT tests are similar.