RESUMO
Introduction: Helicobacter pylori is a well-studied infectious agent due to its pathogenic potential for peptic ulcers and gastric cancer. It has a high prevalence worldwide and has several diagnostic methods, both invasive and non-invasive. It is important to address the diagnostic efficacy of these tests, as the data vary by location and the specific population in which they are used. Therefore, an effective testing method should be obtained, evaluating the possibility of substantially reducing invasive procedures and, therefore, associated costs. OBJECTIVE: This study proposes to define the diagnostic accuracy of the stool antigen test for H. pylori infection in the Dominican Republic. METHODS: An observational, retrospective, and cross-sectional study was conducted. The results of the stool antigen test for H. pylori infection were compared with the results of the gastric biopsy, as a gold standard test. Patients over 18 years of age with an indication for endoscopy due to suspicion of H. pylori infection, who attended the gastroenterology clinic in 2021, were included in the study. RESULTS: It was shown that the stool antigen test for H. pylori infection has a 61.54% sensitivity and 59.65% specificity. According to the study population, the positive predictive value (PPV) was 67.60% and the negative predictive value (NPV) was 53.13%. CONCLUSION: Low numbers of both sensitivity and specificity were determined, which is why it is pertinent to study alternative non-invasive methods. However, it is important to assess the antibiotic exposure of the study population, since the diagnostic accuracy of the stool test can be influenced by this factor.
RESUMO
The use of nanomaterials for the controlled release of drugs aims to enhance their effectiveness, especially when poorly soluble in water, and achieve their rapid, localized, and effective administration. The present study focuses on the use of a Zeolitic Imidazolate Framework-8 (ZIF-8) as vehicle for the transport and controlled release of the antibiotic ciprofloxacin (CIP) as model due to its favorable physicochemical characteristics. The objective is to synthesize the ZIF-8 material loaded with CIP through encapsulation for subsequent release of the drug in neutral and acid physiological media. In addition, functionalization of the CIP/ZIF compound with magnetic nanoparticles (NP) was sought to increase its traceability through the possible use of magnetic fields. Characterizations by XRD, FT-IR, SEM-EDX, and TGA showed a satisfactory synthesis of both pure ZIF-8 and ciprofloxacin-loaded ZIF-8, with high crystallinity and thermal stability. The release profiles showed an abrupt initial release that stabilized over time. A much higher release (20-80% greater) was obtained in acid versus neutral pH in all cases, attributable to the collapse of the ZIF-8 structure in acid media. In addition, functionalization of the material with iron NPs did not affect the behavior of the system during drug release. Antimicrobial activity tests against E. coli and S. aureus showed that ZIF-8 per se exerts antimicrobial activity, while the compounds CIP/ZIF and magnetic CIP/ZIF increased the antimicrobial capacity of pure CIP by 10-20%. The ZIF-8 system has high potential as a drug carrier and release agent for the treatment of diseases, especially those that cause acidification of the cellular environment, achieving a rapid, localized, and targeted action with the possibility of achieving traceability of the system after its magnetic functionalization.
