O estudo teórico do desempenho dos polímeros condutores dos corantes azoicos na detecção eletroquímica de indigo-carmim / The theoretical study of the function of conducting polymers of the azo-dyes in the electrochemical detection of indigo-carmine

RESUMO O desempenho dos polímeros condutores dos corantes azoicos durante a detecção eletroquímica de indigo-carmim foi investigado do ponto de vista teórico, sendo o modelo, correspondente ao caso, descrito e analisado mediante a teoria de estabilidade lineal e da análise de bifiircações. Foi mostrado que o sistema eletroanalítico depende fortemente do pH, pois as concentrações excessivas dos prótons levam à ineficiência eletroanalítica, haja vista o bloqueio dos centros ativos da reação. No entretanto, malgrado o supracitado, os polímeros dos corantes azoicos são modificadores eficientes para determinação do indigo-carmim. A possibilidade das instabilidades oscilatória e monotônica também foi verificada.

SUMMARY The function of the conducting polymers of azo-dyes during the indigo-carmine electrochemical detection has been investigated from the theoretical point of view. The correspondent model has been described and analyzed by means of linear stability theory and bifurcation analysis. It has been shown that the electroanalytical system depends strongly on pH, as the excessive protons concentrations drive the system to the electroanalytical inefficiency, as they block the reaction active sites. Nevertheless, despite of the mentioned, the azo-dyes conducting polymers are efficient modifiers for indigo-carmine electrochemical determination. The possibility of oscillatory and monotonic instabilities has also been verified.

The Effect of Indigocarmine on Improvement of the Polyp Detection Rate during Colonoscopic Examination with Hood Cap

BACKGROUND/AIMS: Hood cap-assisted chromocolonoscopy using indigocarmine is expected to improve the detection rate of colorectal polyps, especially adenomatous polyps. Therefore, aim of the present study was to evaluate the usefulness of hood cap-assisted chromocolonoscopy in routine colonoscopic examinations. METHODS: From January, 2013 through March, 2013, a total of 86 patients were enrolled (M:F=33:53, mean age=60 years). For each patient, hood cap-assisted colonoscopic examination was performed, followed by hood cap-assisted chromocolonoscopy using 0.2% indigocarmine from the cecum to the hepatic flexure. Total numbers and characteristics of polyps were compared before and after indigo carmine dye spraying. RESULTS: Prior to dye spraying, 48 polyps were found in 37 patients, and after dye spraying, 53 additional polyps were found in 34 patients. Of these undetected polyps, 45 (85%) were small sized polyps (< or =0.5 cm). Histologically, 19 (36%) were adenomatous polyps, and of these, 15 (28%) were tubular adenomas and 4 (8%) were serrated adenomas. As for the polyp detection rate, there was no difference between the expert and the non-expert groups. CONCLUSION: Hood cap-assisted chromocolonoscopic examination using indigocarmine was helpful in detecting cecum and ascending colon polyps, especially small sized polyps (<0.5 cm) and neoplastic polyps.

Successful Bile Duct Cannulation Guided by Indigocarmine Injection via PTGBD / 대한소화기내시경학회지

Even though percutaneous transhepatic gallbladder drainage (PTGBD) is performed prior to ERCP or following ERCP because of the patients' medical condition or failed bile duct cannulation, there are no definite endoscopic landmarks that are useful for successful bile duct cannulation in some cases. We report here on 4 patients in whom selective bile duct cannulation, as guided by the endoscopic landmarks, was successful following indigocarmine injection via PTGBD.

Is Chromoendoscopy with Indigocarmine Useful for Detecting Additional Lesions in Patients Referred for Endoscopic Resection of Gastric Adenoma or Cancer? / 대한소화기내시경학회지

BACKGROUND/AIMS: Endoscopic mucosal resection (EMR) is frequently performed for the treatment of gastric adenoma or early gastric cancer. These lesions are commonly associated with atrophic gastritis and synchronous lesions are not uncommon. The aim of this study was to evaluate the usefulness of chromoendoscopy with indigocarmine in detecting additional lesions patients referred for EMR. METHODS: Chromoendoscopy was performed in 51 patients (M : F=41 : 10, mean age= 60 year). After a careful examination, the stomach was stained with a 30 mL of indigocarmine (0.2%) with a spraying catheter. The changes in size of the lesions and the possibility of finding additional lesions were compared between before and after spraying dye. RESULTS: Before dye-spraying, six additional lesions were found. On the other hand, before the chromoendoscopy with indigocarmine. And among these, microscopic examination confirmed the presence of adenomas for additional three lesions. After spraying indigocarmine, eight additional lesions were found suspicious for adenoma, after the dye spraying. However, there was no neoplastic lesions histopathologically. With dye-spraying, the lesions looked bigger in four cases. And the three lesions among them showed similar size compared to the patholgic report. CONCLUSIONS: A conventional gastroscopic examination was enough to find additional adenoma or cancer, whereas chromoendoscopy was not so helpful in detecting additional lesions. In addition, because indigocarmine dye-spraying could outline mucosal elevations, chromoendoscopy was benefical in accurately measuring the size of the lesion.