Effectiveness of Dual-Focus Magnification on Confidence Levels in Optical Diagnosis of Small Colorectal Polyps.

Background and objectives Achieving accurate real-time optical diagnoses of colorectal polyps with high-confidence predictions is crucial for appropriate decision-making in daily practice. The dual-focus (DF) magnification mode helps endoscopists scrutinize subtle features of polyp surfaces and vessel patterns. This prospective study aimed to evaluate the impact of DF imaging on enhancing the rate of high-confidence narrow-band imaging (NBI)-based optical diagnosis. Methods Consecutive adult patients who underwent colonoscopy and had small colorectal polyps (<10 mm) were enrolled between September 2022 and May 2023. The optical diagnosis of each polyp was evaluated during colonoscopy in two stages by the same endoscopist, utilizing NBI with DF magnification (NDB-DF). A confidence level was assigned to each prediction. High confidence was indicated by clinical judgment when a polyp exhibited distinctive features associated solely with one histological subtype and lacked characteristics of any other subtype. All procedures were carried out with a prototype 190 series Exera III NBI system (Olympus Corporation, Tokyo, Japan) with DF magnification. Results The study included 413 patients with 623 polyps, comprising 483 ≤ 5 mm and 140 measuring 6-9 mm. The majority were low-grade adenomas (343 lesions), with 17 identified as high-grade adenomas, and none characterized as deep submucosal invasive carcinomas. NBI-DF significantly improved the rate of high-confidence optical diagnoses compared to NBI for both ≤ 5 mm polyps (93.1% vs. 87.5%, p < 0.0001) and 6-9 mm polyps (97.9% vs. 94.2%, p = 0.03). Furthermore, DF significantly facilitated the assessment of microvessel and surface pattern criteria (p < 0.01). Conclusion DF magnification markedly enhanced the rate of high-confidence NBI-based optical predictions for small colorectal polyps. This technique demonstrates the potential for improving the diagnostic yield in real-time optical diagnosis of colorectal polyps in the Vietnamese setting.

Clinical characteristics and risk factors of gastroesophageal reflux disease in Vietnamese patients with upper gastrointestinal symptoms undergoing esophagogastroduodenoscopy.

BACKGROUND AND AIM: The risk factors associated with the increase in prevalence of gastroesophageal reflux disease (GERD) are not consistent across countries and there have been few studies in Asia in the past 10 years. This study was conducted to assess the features and risk factors of GERD in Vietnamese patients. METHODS: A cross-sectional study was conducted on 1947 out-patients ≥18 years of age who were presented with upper gastrointestinal symptoms and underwent esophagogastroduodenoscopy. Reflux esophagitis was graded according to the Los Angeles classification. Endoscopically suspected Barrett's esophagus (BE) was recorded according to the Prague C and M criteria and biopsy was taken for histologic examination. RESULTS: There were 511 (26.2%) patients with GERD, 242 (47.4%) with nonerosive reflux disease, and 269 (52.6%) with reflux esophagitis and/or BE. Epigastric pain, regurgitation, and heartburn were the chief complaints in 36.8%, 27.0%, and 9.2% of patients, respectively. Most of the patients with mucosal injury had reflux esophagitis in mild grade and BE in the form of C0M ≤2 (99.6%, 231/232 and 97.8%, 46/47, respectively). In multivariate analysis, hiatal hernia, male gender, waist-to-hip ratio (independent from general obesity), and smoking were risk factors for GERD while Helicobacter pylori infection was negatively associated with GERD. CONCLUSIONS: The majority of GERD patients had none or mild mucosal injury. Typical reflux symptoms, however, may not be the chief complaints. Central obesity would be more important than general obesity as a risk factor, while H. pylori infection was a "protective" factor for GERD in Vietnamese patients.

Prevalence, clinical characteristics, and risk factors of Barrett esophagus in Vietnamese patients with upper gastrointestinal symptoms.

The current barrier for investigation of Barrett esophagus (BE) in Asia is diagnostic standardization, which is a challenge to identify its true risk factors. This study aimed to investigate the prevalence, clinical characteristics and risk factors of BE in Vietnamese patients with upper gastrointestinal symptoms.A cross-sectional study was conducted on consecutive outpatients who underwent upper gastrointestinal endoscopy. Endoscopically suspected esophageal metaplasia (ESEM) which was clearly visible at least 1 cm above the gastroesophageal junction at endoscopy was taken biopsy. At least 1 biopsy per 2 cm in tongues of ESEM and 4 biopsies per 2 cm of circumferential ESEM were taken. The diagnostic criterion for BE was replacement of the normal squamous epithelial lining by columnar epithelium confirmed by histology.A total of 1947 patients were recruited. Forty-seven out of 58 patients with ESEM were histologically confirmed BE. The prevalences of BE and hiatal hernia (HH) were 2.4% (95% confidence interval [CI], 1.7-3.1%) and 2.3% (95% CI, 1.6-2.9%), respectively. Heartburn and/or regurgitation presented in only 61.7% (95% CI, 46.4-75.5%) of patients with BE. In multivariate analysis, the only 2 factors significantly associated with BE were HH (OR 7.53; 95% CI, 3.13-18.11; P < .001) and typical reflux symptom (OR 2.07; 95% CI, 1.12-3.83; P = .020).BE is not uncommon in Vietnamese patients with upper gastrointestinal symptoms. In addition, typical reflux symptoms and HH are the risk factors for BE in Vietnamese.

Multimode smartphone biosensing: the transmission, reflection, and intensity spectral (TRI)-analyzer.

We demonstrate a smartphone-integrated handheld detection instrument capable of utilizing the internal rear-facing camera as a high-resolution spectrometer for measuring the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum from a microfluidic cartridge inserted into the measurement light path. Under user selection, the instrument gathers light from either the white "flash" LED of the smartphone or an integrated green laser diode to direct illumination into a liquid test sample or onto a photonic crystal biosensor. Light emerging from each type of assay is gathered via optical fiber and passed through a diffraction grating placed directly over the smartphone camera to generate spectra from the assay when an image is collected. Each sensing modality is associated with a unique configuration of a microfluidic "stick" containing a linear array of liquid chambers that are swiped through the instrument while the smartphone captures video and the software automatically selects spectra representative of each compartment. The system is demonstrated for representative assays in the field of point-of-care (POC) maternal and infant health: an ELISA assay for the fetal fibronectin protein used as an indicator for pre-term birth and a fluorescent assay for phenylalanine as an indicator for phenylketonuria. In each case, the TRI-analyzer is capable of achieving limits of detection that are comparable to those obtained for the same assay measured with a conventional laboratory microplate reader, demonstrating the flexibility of the system to serve as a platform for rapid, simple translation of existing commercially available biosensing assays to a POC setting.

Characterization of drug authenticity using thin-layer chromatography imaging with a mobile phone.

Thin-layer chromatography (TLC) has a myriad of separation applications in chemistry, biology, and pharmacology due to its simplicity and low cost. While benchtop laboratory sample application and detection systems for TLC provide accurate quantitation of TLC spot positions and densities, there are many applications where inexpensive and portable instruments would greatly expand the applicability of the technology. In this work, we demonstrate identity verification and concentration determination of pharmaceutical compounds via TLC using a custom 3D-printed cradle that interfaces with an ordinary mobile phone. The cradle holds the mobile phone's internal, rear-facing camera in a fixed position relative to a UV lamp and a TLC plate that includes a phosphor in the stationary phase. Analysis of photographs thus reveals the locations and intensities of principal spots of UV--absorbing drugs. Automated image analysis software determines the center location and density of dark spots, which, using integrated calibration spots of known drug compounds and concentrations, can be used to determine if a drug has been diluted or substituted. Two independent image processing approaches have been developed that may be selected based upon the processing capabilities of the smartphone. Each approach is able to discern 5% drug concentration differences. Using single-component solutions of nevirapine, amodiaquine, and paracetamol that have been manually applied, the mobile phone-based detection instrument provides measurements that are equivalent to those obtained with a commercially available lab-based desktop TLC densitometer.