When should patients take simethicone orally before colonoscopy for avoiding bubbles: A single-blind, randomized controlled study.

BACKGROUND: Many studies have reported the use of simethicone before colonoscopy removes bubbles. However, guidelines weakly recommend simethicone administration before colonoscopy. The present study aimed to confirm the advantages of taking simethicone and determine the appropriate time for taking simethicone. METHODS: We randomly assigned patients to the following 5 groups according to the administration time: 4 groups were divided based on 2 parameters (the day before and on the day of colonoscopy and before and after bowel cleansing) and the remaining group was the control group. We compared bubble score (BS), number of simethicone solution irrigations when visually obscured, satisfaction score of the endoscopist, insertion time. RESULTS: A total of 204 patients were included in the study. There was a difference in BS according to the timing of simethicone administration (P < .001). The group taking simethicone on the day of the test had a better BS than the group taking simethicone the day before (P < .001). The group taking simethicone on the previous day had a better BS than the control group (P = .001). In the group of taking simethicone on the examination day, the number of irrigations was lower, and satisfaction with the inspector was higher than group of taking simethicone on previous day and control group (both P < .001). The insertion time showed a non-significantly decreasing trend (P = .417). CONCLUSION: Administering simethicone reduced bubbles and facilitated effective colonoscopy, especially when administrating it on the day of examination. It needs to be administered on the day of the examination regardless of bowel preparation.

How is gut microbiome of patients with familial adenomatous polyposis different from healthy people?

The gut microbiome has been increasingly suggested as an underlying cause of various human diseases. In this study, we hypothesized that the gut microbiomes of patients with familial adenomatous polyposis (FAP) are different from those of healthy people and attempted to identify the associations between gut microbiome characteristics and FAP. We collected fecal samples from patients with FAP and healthy volunteers and evaluated the diversity, composition, and distribution of the gut microbiome between the 2 groups via 16S rRNA-based taxonomic profiling of the fecal samples. Fecal samples were collected from 10 patients with FAP (4 men and 6 women, mean age 39.2 ±â€…13.8 years) and 10 healthy volunteers (4 men and 6 women, mean age 40.9 ±â€…9.8 years). The microbial richness in patients with FAP was significantly lower than that in healthy people. Regarding microbial composition, the Firmicutes/Bacteroidetes ratio in patients with FAP was higher than that in healthy people, especially in those with a lower proportion of Bacteroidetes and a higher proportion of Proteobacteria. We also found 7 specific abundant strains in fecal samples of patients with FAP. Patients with FAP had different Firmicutes/Bacteroidetes ratios and Proteobacteria abundance compared to healthy people and showed the presence of specific bacteria. These findings suggest a promising role of the gut microbiome in patients with FAP, although further studies are needed.

An R-peak detection method that uses an SVD filter and a search back system.

In this paper, we present a method for detecting the R-peak of an ECG signal by using an singular value decomposition (SVD) filter and a search back system. The ECG signal was detected in two phases: the pre-processing phase and the decision phase. The pre-processing phase consisted of the stages for the SVD filter, Butterworth High Pass Filter (HPF), moving average (MA), and squaring, whereas the decision phase consisted of a single stage that detected the R-peak. In the pre-processing phase, the SVD filter removed noise while the Butterworth HPF eliminated baseline wander. The MA removed the remaining noise of the signal that had gone through the SVD filter to make the signal smooth, and squaring played a role in strengthening the signal. In the decision phase, the threshold was used to set the interval before detecting the R-peak. When the latest R-R interval (RRI), suggested by Hamilton et al., was greater than 150% of the previous RRI, the method of detecting the R-peak in such an interval was modified to be 150% or greater than the smallest interval of the two most latest RRIs. When the modified search back system was used, the error rate of the peak detection decreased to 0.29%, compared to 1.34% when the modified search back system was not used. Consequently, the sensitivity was 99.47%, the positive predictivity was 99.47%, and the detection error was 1.05%. Furthermore, the quality of the signal in data with a substantial amount of noise was improved, and thus, the R-peak was detected effectively.

Reactive processing of recycled polycarbonate/acrylonitrile butadiene styrene.

Cellular phone housings were ground to make original particulates using a knife mill. Foams and adhesives with a lighter density than water were removed from ground mixtures using a sink-float process in water; ground metals, button rubbers, and wires were separated from desired materials by using a sink float process in salt All housing materials, consisting of seven thermoplastics included in cellular phone housings, showed better tensile properties than pure housing materials made of polycarbonate/acrylonitrile butadiene styrene, but they only had about half of the impact strength. In contrast, the low impact strength for all housing materials was improved by adding 25 wt % polyethylene elastomer and/or 2.4 wt % ground epoxy circuit boards for batch mixing. Impact strengths, tensile strengths, and the energy absorption ability of all housing materials were improved by adding 5.4wt% glycidyl methacrylate for twin screw extrusion.

Structural insight into bioremediation of triphenylmethane dyes by Citrobacter sp. triphenylmethane reductase.

Triphenylmethane dyes are aromatic xenobiotic compounds that are widely considered to be one of the main culprits of environmental pollution. Triphenylmethane reductase (TMR) from Citrobacter sp. strain KCTC 18061P was initially isolated and biochemically characterized as an enzyme that catalyzes the reduction of triphenylmethane dyes. Information from the primary amino acid sequence suggests that TMR is a dinucleotide-binding motif-containing enzyme; however, no other functional clues can be derived from sequence analysis. We present the crystal structure of TMR in complex with NADP+ at 2.0-angstroms resolution. Despite limited sequence similarity, the enzyme shows remarkable structural similarity to short-chain dehydrogenase/reductase (SDR) family proteins. Functional assignments revealed that TMR has features of both classic and extended SDR family members and does not contain a conserved active site. Thus, it constitutes a novel class of SDR family proteins. On the basis of simulated molecular docking using the substrate malachite green and the TMR/NADP+ crystal structure, together with site-directed mutagenesis, we have elucidated a potential molecular mechanism for triphenylmethane dye reduction.

Identification of an alternative translation initiation site for the Pantoea ananatis lycopene cyclase (crtY) gene in E. coli and its evolutionary conservation.

Previous sequence analyses of the lycopene cyclase gene (crt Y) from Pantoea ananatis revealed that translation of its protein product in Escherichia coli began at the ATG start codon. We found, however, that this enzyme could also be produced in E. coli without the ATG start codon present. Results of experiments using crt Y mutants revealed that a GTG (Val) sequence, located in-frame and 24 bp downstream of the ATG, could act as a potential start codon. Additionally, a point-mutated GTA (Val), replaced from alternative GTG start codon, also displayed its potential as a start codon although the strength as a translation initiation codon was considerably weak. This finding suggests that non-ATG codons, especially one base pairing with the anticodon (3'-UAC-5') in fMet-tRNA, might be also able to function as start codon in translation process. Furthermore, amino acid sequence alignment of lycopene cyclases from different sources suggested that a Val residue located within the N-terminus of these enzymes might be used as an alternative translation initiation site. In particular, presence of a conserved Asp, located in-frame and 12 bp upstream of potential start codon, supports this assumption in view of the fact that Asp (GAT or GAC) can function as part of the Shine-Dalgano sequence (AGGAGG).

Enhanced protease cleavage efficiency on the glucagon-fused interleukin-2 by the addition of synthetic oligopeptides.

Human interleukin-2 (hIL-2) was produced as a recombinant fusion protein (G3.IL-2/HF) consisting of three tandem-arranged human glucagon molecules (G3) and hIL-2. For the recovery of hIL-2, a factor Xa (FXa) cleavage sequence was introduced next to the N-terminus of hIL-2. Cleavage efficiency on this recombinant protein construct was very low because its recognition sequence was sterically hindered within the G3.IL-2/HF molecule and hence FXa access to the cleavage site was insufficient. We therefore introduced various synthetic oligopeptides upstream from the FXa cleavage site as a means to change substrate conformation and thereby increase cleavage efficiency. Among these oligopeptides, acidic or nucleophilic constructs were the most effective for the FXa-mediated cleavage of the fusion protein. In addition, insertion of various oligopeptides into the G3.IL-2/HF molecule varied the solubility of each construct depending on their physical properties. Consequently, the G3.IL-2/DF construct showed the highest final hIL-2 yields via FXa-mediated removal of the fusion partner. Lastly, we confirmed that cleavage efficiency was greatly increased but native hIL-2 was cleaved internally by non-specific cleavage when the acidic oligopeptide D4 (DDDD) was introduced upstream of the EK cleavage site within G3.IL-2/HE molecule. The G3.IL-2/HE molecule was shown to be an inefficient substrate to EK in a previous report (Biotechnol. Bioprocess Eng. (2000) 5, 13-16).

Identification of a fibrinolytic enzyme by Bacillus vallismortis and its potential as a bacteriolytic enzyme against Streptococcus mutans.

A potent fibrinolytic enzyme-producing bacterium was isolated from the traditional Korean condiment Chungkook-jang and identified as Bacillus vallismortis Ace02. The extracellular fibrinolytic enzyme was purified with a 18% recovery of activity from supernatant cultures using CM-Sepharose column chromatography and Sephacryl S-200 gel filtration. The specific activity of the purified enzyme was 757 kFU mg(-1). Its molecular mass was about 28 kDa and the initial amino acids of the N-terminal sequence were AQSVPYGVSQ. The full amino acid sequence of fibrinolytic enzyme Ace02 corresponded with bacteriolytic enzyme, L27, from Bacillus licheniformis, which has strong lytic activity against Streptococcus mutans, a major causative strain of dental caries. This suggests that the purified enzyme should be used for prevention of dental caries as well as being an effective thrombolytic agent.