Prevalence and risk factors of erosive esophagitis in Taiwan.

BACKGROUND: Erosive esophagitis is a common condition in the western population. However, the prevalence and risk factors of this disorder in Taiwan remain unclear. This study investigated the current prevalence of erosive esophagitis in Taiwan and attempted to identify the risk factors for this disease. METHODS: From January 2008 to May 2009, 2040 consecutive subjects who underwent upper gastrointestinal endoscopy during their annual health check-up were enrolled. The severity of erosive esophagitis was evaluated according to the Los Angeles classification, and the independent risk factors of erosive esophagitis were analyzed using the logistic regression method. RESULTS: The prevalence of erosive esophagitis was 17.3% (352/2040), with 71.6%, 27.8%, 0.5% and 0% cases of grades A, B, C and D, respectively, according to the Los Angeles classification. Univariate analysis revealed that male sex, smoking, alcohol consumption, betel nut chewing habit, body mass index ≥ 27 kg/m(2), hypertension, use of calcium channel blockers, diabetes, hyperglycemia, hypertriglyceridemia, and hiatus hernia were associated with the development of erosive esophagitis. Multivariate analysis revealed that male sex [odds ratio (OR) = 2.013, 95% confidence interval (CI) = 1.439-2.815; p < 0.001), smoking (OR = 1.301, 95% CI = 1.089-1.555; p = 0.004), body mass index > 27 (OR = 1.348, 95% CI = 1.138-1.598; p = 0.001), and hiatus hernia (OR = 4.331, 95% CI = 3.304-5.784; p < 0.001) were independent risk factors for the development of erosive esophagitis. CONCLUSION: The current prevalence of erosive esophagitis in Taiwan is 17.3%. Male sex, smoking, obesity, and hiatus hernia are four independent risk factors for the development of erosive esophagitis in the Taiwanese population.

Solution-phase surface modification in intact poly(dimethylsiloxane) microfluidic channels.

An improved approach composed of an oxidation reaction in acidic H2O2 solution and a sequential silanization reaction using neat silane reagents for surface modification of poly(dimethylsiloxane) (PDMS) substrates was developed. This solution-phase approach is simple and convenient for some routine analytical applications in chemistry and biology laboratories and is designed for intact PDMS-based microfluidic devices, with no device postassembly required. Using this improved approach, two different functional groups, poly(ethylene glycol) (PEG) and amine (NH2), were introduced onto PDMS surfaces for passivation of nonspecific protein absorption and attachment of biomolecules, respectively. X-ray electron spectroscopy and temporal contact angle experiments were employed to monitor functional group transformation and dynamic characteristics of the PEG-grafted PDMS substrates; fluorescent protein solutions were introduced into the PEG-grafted PDMS microchannels to test their protein repelling characteristics. These analytical data indicate that the PEG-grafted PDMS surfaces exhibit improved short-term surface dynamics and robust long-term stability. The amino-grafted PDMS microchannels are also relatively stable and can be further activated for modifications with peptide, DNA, and protein on the surfaces of microfluidic channels. The resulting biomolecule-grafted PDMS microchannels can be utilized for cell immobilization and incubation, semiquantitative DNA hybridization, and immunoassay.

Multistep synthesis of a radiolabeled imaging probe using integrated microfluidics.

Microreactor technology has shown potential for optimizing synthetic efficiency, particularly in preparing sensitive compounds. We achieved the synthesis of an [(18)F]fluoride-radiolabeled molecular imaging probe, 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), in an integrated microfluidic device. Five sequential processes-[18F]fluoride concentration, water evaporation, radiofluorination, solvent exchange, and hydrolytic deprotection-proceeded with high radio-chemical yield and purity and with shorter synthesis time relative to conventional automated synthesis. Multiple doses of [18F]FDG for positron emission tomography imaging studies in mice were prepared. These results, which constitute a proof of principle for automated multistep syntheses at the nanogram to microgram scale, could be generalized to a range of radiolabeled substrates.