Development and validation of the HPLC-DAD method for the quantification of 16 synthetic dyes in various foods and the use of liquid anion exchange extraction for qualitative expression determination.

Synthetic dyes can cause many health problems, and their use as food additives is rigorously regulated worldwide. Two methods for the determination of synthetic dyes in food are described in this article. The visual qualitative expression method was based on the extraction of synthetic dyes using a liquid anion exchanger (0.01 M solution of trioctylmethylammonium chloride in chloroform). Using this reagent, an optimal transition of 15 anionic synthetic dyes from the aqueous to the organic phase was achieved (R > 99.8%). It was applicable for testing food that must not contain synthetic dyes (wines, juices, etc.) in a very short time (5-10 min). In the case of colouring of the organic phase, identification and quantification was carried out using the HPLC-DAD method described. The rapid and simple method allows for simultaneous determination of 16 synthetic dyes from all food types. The LOD and LOQ ranged from 0.026 to 0.086 µg mL-1 and from 0.077 to 0.262 µg mL-1 respectively, and recovery was 83.7-107.5%. Hypothesis: anionic synthetic dyes have hydrophobic properties, as a result they are retained on the non-polar stationary phase of the chromatographic column and are easily extracted from aqueous solutions by liquid anion exchangers.

An optimization approach for fast, simple and accurate determination of indigo-carmine in food samples.

This study report optimization of vortex-assisted natural deep eutectic solvent based liquid-phase microextraction (VA-NADES-LPME) for determination of indigo-carmine in some food samples by UV-Visible spectrophotometer. To ensure efficient extraction, nine different NADES were prepared and tested for the extraction of indigo-carmine. In order to increase extraction efficiency of indigo-carmine, the effects of VA-NADES-LPME variables and their interactions were optimized with central composite design. The optimized method exhibited a linear range between 10 and 900 ng mL-1. Limit of detection, limit of quantification and enrichment factor were determined as 3.3 ng mL-1, 10 ng mL-1 and 135-fold, respectively. The applicability of the optimized method was investigated in selected food samples using the matrix-matching calibration curve. Using optimised experimental conditions (pH of 3.2, 75 µL of NADES-4, 285 µL of THF, and 4 min vortexing), satisfactory recovery results were found in the range of 95.9-104.2% with 1.4-3.7% of relative standard deviation. Finally, the optimized method was economical, simple, green, requires less laborious sampling, and provides superior accuracy and precision in trace-level analysis.

High Radiofrequency Surgery and Chromoendoscopy: A Novel Surgical Technique for the Treatment of Respiratory Papillomatosis.

Recurrent Respiratory Papillomatosis is a highly recurrent and residual disease. The use of indigo-carmine chromoendoscopy increases the early detection of nonvisible disease and reduces the possibility of leaving residual lesions. The best chances of papillomatosis being eradicated depend upon a surgical shallow epitheliolysis approach applied to patients who have never been surgically damaged before. We developed a novel surgical technique based upon the use of a time controlled High Radiofrequency (HRF) energy output. We applied a three-step bloodless HRF-surgical technique, that is, epitheliolysis, angiolysis and peeling without the aid of adjunct therapies. It acts according to differences in the water density of the tissues. We use it to remove the epithelial viral reservoir thus preserving subepithelial layers. For this purpose, we designed and manufactured a custom-made HRF electrodes set for office and O.R. use. From 2005 to 2018, 39 patients (100%) with recurrent respiratory papillomatosis participated in the present prospective work. Twenty-five (64,10%) achieved complete postsurgical remission, 6 (15,38%) were lost to follow up, and 8 (20,51%) present partial remissions. Thirty-six patients had laryngeal papillomatosis. Follow-up was possible in 30 of the 36 patients with laryngeal papillomatosis with a success remission rate of 83,33% (25 of 30). Eleven of those 36 (30,55%) entered this study without previous surgical treatment and 9 of 11 (81,81%) were cured. Indigo-carmine chromoendoscopy, a visualization solution for papillomatosis detection, together with a bloodless HRF-surgical technique proved to be effective tools to eradicate papillomatosis. Voice restoration to normal or near normal levels was achieved in all patients.

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.

Severe hypertension and tachycardia during transforaminal endoscopic discectomy - Is indigocarmine to blame?

Endoscopic transforaminal discectomy is a minimally invasive technique used for the surgical treatment of herniated discs. Indigocarmine is a dye which is widely used to identify the ureteral orifice in urologic procedures. Hemodynamic effects such as hypotension and anaphylaxis in addition to hypertension, bradycardia and atrioventricular block have been reported in intravenous application of indigocarmine. The aim of this case report is to prepare anesthesiologists for such cases and make them consider invasive blood pressure monitorization. Both patients had radicular pain radiating to the leg and scheduled to undergo transforaminal endoscopic discectomy. Intraoperative vital signs were within normal limits, however severe hypertension and tachyarrhythmia developed following the injection. Hemodynamics in both patients returned to normal following lidocaine and nitroglycerine injection.

Toward an easier indigocarmine chromoendoscopy.

Indigocarmine chromoendoscopy has been proven to improve the detection of colonic lesions during screening colonoscopy, and is associated with increased adenoma detection rates. Furthermore, it is commonly used to help in the delineation and characterization of colorectal neoplasms. However, it usually requires the use of a spraying catheter that decreases the suction capacity of the endoscope, and is time- consuming. Herein, we report on the feasibility of indigo carmine chromoendoscopy during colonoscopy without using a spraying catheter, with the dye being administered through the air/water channel of the endoscope. Since the suction channel remains free, the air can be exsufflated and the staining then applies uniformly onto the colonic walls with the excess indigocarmine dye being immediately eliminated. In our experience with various types of colonoscopes and cap-assisted colonoscopy, this procedure makes indigocarmine chromoendoscopy much easier and quicker to perform, and might save the use of a spray catheter.

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 (≤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.

Chromoendoscopy of gastric adenoma using an acetic acid indigocarmine mixture.

AIM: To investigate the usefulness of chromoendoscopy, using an acetic acid indigocarmine mixture (AIM), for gastric adenoma diagnosed by forceps biopsy. METHODS: A total of 54 lesions in 45 patients diagnosed as gastric adenoma by forceps biopsy were prospectively enrolled in this study and treated by endoscopic submucosal dissection (ESD) between January 2011 and January 2012. AIM-chromoendoscopy (AIM-CE) was performed followed by ESD. AIM solution was sprinkled and images were recorded every 30 s for 3 min. Clinical characteristics such as tumor size (< 2 cm, ≥ 2 cm), surface color in white light endoscopy (WLE) (whitish, normochromic or reddish), macroscopic appearance (flat or elevated, depressed), and reddish change in AIM-CE were selected as valuables. RESULTS: En bloc resection was achieved in all 54 cases, with curative resection of fifty two lesions (96.3%). Twenty three lesions (42.6%) were diagnosed as well-differentiated adenocarcinoma and the remaining 31 lesions (57.4%) were gastric adenoma. All adenocarcinoma lesions were well-differentiated tubular adenocarcinomas and were restricted within the mucosal layer. The sensitivity of reddish color change in AIM-CE is significantly higher than that in WLE (vs tumor size ≥ 2 cm, P = 0.016, vs normochromic or reddish surface color, P = 0.046, vs depressed macroscopic type, P = 0.0030). On the other hand, no significant differences were found in the specificity and accuracy. In univariate analysis, normochromic or reddish surface color in WLE (OR = 3.7, 95%CI: 1.2-12, P = 0.022) and reddish change in AIM-CE (OR = 14, 95%CI: 3.8-70, P < 0.001) were significantly related to diagnosis of early gastric cancer (EGC). In multivariate analysis, only reddish change in AIM-CE (OR = 11, 95%CI: 2.3-66, P = 0.0022) was a significant factor associated with diagnosis of EGC. CONCLUSION: AIM-CE may have potential for screening EGC in patients initially diagnosed as gastric adenoma by forceps biopsy.

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.

Diagnosis of Helicobacter pylori infection in gastric mucosa by endoscopic features: a multicenter prospective study.

BACKGROUND: Endoscopic features corresponding to pathological findings in the Sydney System have not been identified, and endoscopic diagnosis of chronic gastritis has not yet been established. To establish the diagnosis of Helicobacter pylori (H. pylori) infection in gastric mucosa by endoscopic features, a prospective multicenter study was carried out. PATIENTS AND METHODS: Two hundred and ninety-seven registered patients from 24 facilities between March 2008 and February 2009 were enrolled. Association between endoscopic findings (conventional findings and indigocarmine contrast (IC) method findings) and diagnosis of H. pylori infection made by microscopic observation of biopsy specimens was investigated in the corpus and antrum and their diagnostic accuracies were investigated. RESULTS: Two hundred and seventy-five patients were analyzed. The area under the receiver operating characteristic (ROC) curve for H. pylori infection of conventional endoscopy was 0.811 in thecorpus and 0.707 in the antrum (P = 0.006). Evaluation of diffuse redness, spotty redness and mucosal swelling by conventional endoscopy and swelling of areae gastricae by the indigocarmine contrast (IC) method were useful for diagnosing H. pylori infection. Regular arrangement of collecting venules (RAC) in the angle, fundic gland polyposis, hemorrhagic erosion and bleeding spot in the corpus and red streaks, and erosions (flat, raised, hemorrhagic and bleeding spot) in the antrum may be used as diagnostic features suggesting negative H. pylori infection. CONCLUSION: It is suggested that endoscopic diagnosis of H. pylori infection in gastric mucosa by conventional endoscopy and the IC method is mostly possible.

Indigocarmine added to the water exchange method enhances adenoma detection - a RCT.

PURPOSE: Chromoendoscopy with dye spray and the water method both increase adenoma detection. HYPOTHESIS: Adding indigocarmine to the water method will enhance further the effectiveness of the latter in adenoma detection. METHODS: Screening colonoscopy was performed with the water method (control) or with 0.008% indigocarmine added (study) by two endoscopists. Randomization was based on computer-generated codes contained in blocks of pre-arranged opaque sealed envelopes. High resolution colonoscopes were used. Upon insertion into the rectum, air was suctioned. With the air pump turned off, water was infused using a blunt needle adaptor connected to the scope channel and a foot pump to facilitate scope insertion until the cecum was reached. Residual stool causing cloudiness was suctioned followed by infusion of clear or colored water (water exchange) to facilitate scope passage with minimal distention of the colonic lumen. Upon seeing the appendix opening under water, water was suctioned and air was insufflated to facilitate inspection on scope withdrawal. STATISTICS: Sample size calculation revealed 168 patients (84/group) needed to be randomized. Study was IRB-approved and registered (NCT01383265). RESULTS: There were no significant differences in mean age, gender distribution, BMI, and family history of colon cancer. Cecal intubation success rate was 100% in both groups. The overall adenoma detection rate was 44% (water only) versus 62% (water with indigocarmine), respectively (p=0.03). One cancer was detected in each group. CONCLUSION: In a RCT, indigocarmine at 0.008% concentration, added to the water method, significantly enhanced further the effectiveness of the latter in detecting adenomas.

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.