Chu-Kuang Chou

Carbon dioxide insufflation can significantly reduce toilet use after colonoscopy: a double-blind randomized controlled trial.

BACKGROUND AND STUDY AIMS Carbon dioxide (CO2) insufflation during colonoscopy can significantly decrease abdominal pain and bloating after the procedure, but its impact on the frequency and duration of toilet use remains unknown. The aim of this study was to assess the impact of CO2 insufflation on toilet use after screening colonoscopy. METHODS From 138 average-risk individuals who underwent screening colonoscopy during March to August 2013, 120 were enrolled and randomized to receive either CO2 or air insufflation at colonoscopy. Both the colonoscopist and participant were blinded to the type of gas used. Abdominal pain and distension were assessed using a visual analog scoring system. The frequency and duration of toilet visits during a 2-hour postcolonoscopy period were recorded using a radiofrequency identification system. RESULTS Baseline characteristics were similar in both groups in terms of age, sex, and procedure time. In the 2 hours after colonoscopy, 50 participants (83 %) in the air group and 18 participants (30 %) in the CO2 group (P < 0.001) used the toilet at least once. The mean (± SD) duration of each toilet visit was 5.93 ± 4.65 minutes in the air group and 1.53 ± 2.84 minutes in the CO2 group (P < 0.001). The abdominal discomfort score was lower in the CO2 group than in the air group both at the end of the colonoscopy (P < 0.001) and 2 hours later (P < 0.001). CONCLUSION Insufflation with CO2 can significantly reduce abdominal discomfort and toilet use after colonoscopy. Use of this technique may help reduce patient burden and allow more efficient use of space in the endoscopy unit.

Non-invasive screening for colorectal cancer in Asia.

There is an increasing trend of colorectal cancer incidence in Asia and nearly 45% of CRC cases worldwide occur in Asia therefore screening for CRC becomes an urgent task. Stool-based tests, including guaiac fecal occult blood test (gFOBT) and fecal immunochemical test (FIT), can select subjects at risk of significant colorectal neoplasms from the large target population thus are currently the most commonly used non-invasive screening tool in large population screening programs. FIT has the advantage over gFOBT in terms of higher sensitivity for early neoplasms, the ability to provide high-throughput automatic analysis, and better public acceptance thus greater effectiveness on reducing CRC mortality and incidence is expected. Owing to the large target population and constrained endoscopic capacity and manpower, FIT is nowadays the most popular CRC screening test in Asia. Some Asian countries have launched nationwide screening program in the past one or two decades but also encountered some challenges such as low screening participation rate, low verification rate after positive stool tests, low public awareness, and insufficient manpower. In addition, some controversial or potential future research issues are also addressed in this review.

On the viscoelastic beam damper for a freely precessing gyroscope

The effect of viscoelastic beam dampers on the removal of the wobble motion of a freely precessing gyroscope is analyzed. Hamiltons Principle for a deformable body having large rigid body rotational motion is derived. The equations of motion are non-linear in nature, so the elastic-viscoelastic correspondence principle is inapplicable. The stress variable method is introduced to overcome the difficulty of integrating the strain energy integral appearing in the variational equations, if the constitutive equations contain the time derivatioves of stress. The numerical solutions show that, the wobble motion of the gyroscope will be eliminated most rapidly if the natural frequency of the beam damper is tuned to equal the nutation frequency of the gyroscope. The decay time constant is a concave function of damping ratio, so large damping also has an adverse effect. Therefore, the peak of the damping factor of frequency-dependent materials should not be located at the nutation frequency. For the simple case in which the single-beam damper is made of a Kelvin type material, an approximate analytical solution is obtained by using the method of multiple scales. The equations, which relate the minimum time constant and the critical damping ratio to the material constants of the damper and the parameters of the system, are obtained in the explicit form. Besides being consistent with the numerical solutions about the above mentioned results, the perturbation solution shows the other important results that for the tuning case, the minimum time constant is inversely proportional to the length of the beam, the nutation frequency of the gyroscope, and the square root of the mass of the tip body.

14 day sequential therapy versus 10 day bismuth quadruple therapy containing high-dose esomeprazole in the first-line and second-line treatment of Helicobacter pylori: a multicentre, non-inferiority, randomized trial

Background Whether extending the treatment length and the use of high-dose esomeprazole may optimize the efficacy of Helicobacter pylori eradication remains unknown. Objectives To compare the efficacy and tolerability of optimized 14 day sequential therapy and 10 day bismuth quadruple therapy containing high-dose esomeprazole in first-line therapy. Methods We recruited 620 adult patients (≥20 years of age) with H. pylori infection naive to treatment in this multicentre, open-label, randomized trial. Patients were randomly assigned to receive 14 day sequential therapy or 10 day bismuth quadruple therapy, both containing esomeprazole 40 mg twice daily. Those who failed after 14 day sequential therapy received rescue therapy with 10 day bismuth quadruple therapy and vice versa. Our primary outcome was the eradication rate in the first-line therapy. Antibiotic susceptibility was determined. ClinicalTrials.gov: NCT03156855. Results The eradication rates of 14 day sequential therapy and 10 day bismuth quadruple therapy were 91.3% (283 of 310, 95% CI 87.4%-94.1%) and 91.6% (284 of 310, 95% CI 87.8%-94.3%) in the ITT analysis, respectively (difference -0.3%, 95% CI -4.7% to 4.4%, P = 0.886). However, the frequencies of adverse effects were significantly higher in patients treated with 10 day bismuth quadruple therapy than those treated with 14 day sequential therapy (74.4% versus 36.7% P < 0.0001). The eradication rate of 14 day sequential therapy in strains with and without 23S ribosomal RNA mutation was 80% (24 of 30) and 99% (193 of 195), respectively (P < 0.0001). Conclusions Optimized 14 day sequential therapy was non-inferior to, but better tolerated than 10 day bismuth quadruple therapy and both may be used in first-line treatment in populations with low to intermediate clarithromycin resistance.