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Background and Aim: Gut microbiota composition is associated with the pathogenesis of non‐alcoholic fatty liver disease. However, the association between gut microbiota composition and non‐alcoholic fatty liver disease in non‐obese patients remains unclear. We compared clinical parameters and gut microbiota profiles of healthy controls and non‐obese and obese patients with non‐alcoholic fatty liver disease. Methods: We examined the clinical parameters and gut microbiota profiles by 16S rRNA sequences and short‐chain fatty acid levels in fecal samples from 51 non‐obese patients with non‐alcoholic fatty liver disease (body mass index <25 kg/m2) and 51 obese patients with non‐alcoholic fatty liver disease (body mass index ≥30 kg/m2) who underwent pathological examination and 87 controls at five hospitals in Japan. Results: Although no significant differences between the non‐obese and other groups were observed in alpha diversity, a significant difference was found in beta diversity. We observed a significant decrease in serum alanine aminotransferase levels, Eubacterium population, and butyric acid levels in non‐obese patients with non‐alcoholic fatty liver disease compared with those in obese patients with non‐alcoholic fatty liver disease. A significant negative correlation was found between the stage of hepatic fibrosis and Eubacterium abundance in non‐obese patients with non‐alcoholic fatty liver disease. Conclusions: The decrease in the abundance of Eubacterium that produces butyric acid may play an important role in the development of non‐alcoholic fatty liver disease in non‐obese individuals. This study was registered at the University Hospital Medical Information Network clinical trial registration system (UMIN000020917). [ABSTRACT FROM AUTHOR]

The freshwater amphipod Crangonyx floridanus (Amphipoda: Crangonyctidae) is considered to have been recently introduced from North America to Japan, and the recorded sites at which it has been collected now cover nearly all of Japan except for the northern part. In this study, we surveyed further areas outside of its known distribution range, and examined the population genetic structure and the phylogenetic relationships between Japanese and North American populations of this species based on nuclear (18S rRNA) and mitochondrial (COI) DNA sequences. We found that this amphipod has already reached Hokkaido, northernmost Japan, which suggests that it has undergone rapid expansion in a pattern of concentric circles from the central part of Japan. Genetic analysis showed that the Japanese population is genetically homogeneous, in contrast to the genetic diversification of this species seen in North American Crangonyx populations. The process of introducing, establishing, and expanding this amphipod in Japan may be explained as follows. A limited number of individuals from a North American native population were probably inadvertently introduced and established somewhere within the Kanto region. The local population size then increased and its distribution range expanded rapidly across Japan. [ABSTRACT FROM AUTHOR]

Abstract: A new sledge net system using propulsion vehicles has been developed to sample more efficiently the demersal juveniles of marine organisms. A net attached to a sledge maneuvered by a SCUBA diver who uses operating switches on a steering handle to adjust the altitude of the sledge and the position of the tickler chains to ensure that the footcloth of the mouth of the net remains in constant contact with the bottom surface. Video camera, flow meter, compass, and dive computers are positioned on the sledge net in the view of the diver. Given that the system can attain speeds of 70cms−1, the net can be employed to capture highly mobile fish. Unlike most boat-based net sampling methods, the use of propulsion vehicles means that there are no sound or vibration disturbances due to the boat and tow ropes typically used to maneuver these types of sampling nets. Marine fauna was collected at monthly intervals over a two-year period in a sampling area along the southern coast of Hokkaido, Japan. A total of 2641 specimens comprising 61 species and including five species which were the first records for the region were collected. These findings suggest that the new sledge net system employing propulsion vehicles was effective for sampling demersal juveniles, particularly in situations where sledge nets towed by boats or push nets cannot be deployed. [Copyright &y& Elsevier]

A 66-year-old man, who had undergone plasma exchange 30 years previously in Egypt for the treatment of falciparum malaria, was referred to our hospital for treatment of chronic hepatitis C (HCV). An analysis of the 655-nucleotide 5'-untranslated region-core region sequence revealed infection with HCV subtype 1g. A phylogenetic analysis of the full-length HCV genome confirmed that the patient's HCV was subtype 1g, which was the first case identified in Japan. Although his HCV possessed several naturally occurring resistance-associated substitutions in the nonstructural (NS) 3 and NS5A regions, he was successfully treated by combination therapy with glecaprevir/pibrentasvir.

Objective: The relationship between Helicobacter pylori and the intestinal microbiota has not yet been clearly demonstrated in children and adolescents. The present study aimed at evaluating how H. pylori infection could affect the intestinal microbiota in adolescents using genetic analysis., Design: Cross-sectional study., Setting and Participants: We included subjects from a longitudinal project involving H. pylori screening and treatment of junior high school third-grade students (aged 14 or 15 years) in Saga Prefecture. The study included a control group (n=79) and an H. pylori group (n=80) tested negative and positive for the anti- H. pylori antibody in the urine and H. pylori antigen in stool specimens, respectively., Interventions: The intestinal microbiota was evaluated in stool specimens using 16S rRNA gene/DNA/amplicon sequencing with next-generation sequencing., Primary and Secondary Outcome Measures: We assessed alpha and beta diversity, just as well as relative abundances within the bacterial composition at the genus level in both groups., Results: As shown by the alpha diversity of the 16S rRNA gene/DNA/amplicon sequence data, the control group exhibited lower microbial species richness with lower alpha diversity compared with the H. pylori group (p<0.001). The beta diversity of the intestinal microbiota profile also differed between the two groups (p<0.01). The relative abundance of the Prevotella genus was higher in the H. pylori group (p<0.01) concomitant with a gain in body mass index (BMI) in the H. pylori group (p<0.01) compared with the control group., Conclusion: H. pylori infection significantly affected the intestinal microbiota in Japanese adolescents. In addition, the prevalence of the Prevotella genus is concomitantly increased along with the BMI in H. pylori -infected students., Trial Registration Number: UMIN000028721., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The aim of this research was to reveal the characteristics of gut microbiome altered by acarbose intervention in Japanese patients with type 2 diabetes (T2D) and its possible association with habitual dietary intake. Eighteen patients with T2D were administered acarbose for four weeks. The abundances of two major phyla, namely Actinobacteria and Bacteroidetes, were reciprocally changed accompanied by the acarbose intervention. There were also significant changes in the abundances of ten genera, including the greater abundance of Bifidobacterium , Eubacterium , and Lactobacillus and the lower abundance of Bacteroides in the group after the intervention than that before the intervention. Hierarchical clustering of habitual dietary intake was performed based on the pattern of changes in the gut microbiota and were classified into distinct three clusters. Cluster I consisted of sucrose, cluster II mainly included fat intake, and cluster III mainly included carbohydrate intake. Moreover, the amount of change in Faecalibacterium was positively correlated with the intake of rice, but negatively correlated with the intake of bread. The intake of potato was negatively correlated with the amount of change in Akkermansia and Subdoligranulum . Acarbose altered the composition of gut microbiome in Japanese patients with T2D, which might be linked to the habitual dietary intake.

An experimental system for serial femtosecond crystallography using an X-ray free-electron laser (XFEL) has been developed. It basically consists of a sample chamber, fluid injectors and a two-dimensional detector. The chamber and the injectors are operated under helium atmosphere at 1 atm. The ambient pressure operation facilitates applications to fluid samples. Three kinds of injectors are employed to feed randomly oriented crystals in aqueous solution or highly viscous fluid. Experiments on lysozyme crystals were performed by using the 10 keV XFEL of the SPring-8 Angstrom Compact free-electron LAser (SACLA). The structure of model protein lysozyme from 1 µm crystals at a resolution of 2.4 Å was obtained.

Background: Although the potential advantages of the Endocut mode (E-mode) of endoscopic sphincterotomy (EST) over the conventional blended cut mode (C-mode) have been reported, the problems, including the small sample size and retrospective analysis, that occurred in previous studies make it difficult to conclude the advantage of the E-mode regarding the safety and efficacy. We performed a prospective randomized controlled study to compare these modes., Methods: A total of 360 patients with choledocholithiasis or stenosis of the bile duct were randomly assigned to one of the modes. To avoid the technical bias due to multiple operators or institutions, the main operator and the institution were restricted to only one experienced doctor and 3 institutions at his place of employment, respectively. We defined pancreatitis, bleeding, and perforation as complications of EST. Besides, bleeding includes endoscopically evident bleeding that was defined as visible during the procedure of sphincterotomy and temporary slight oozing., Results: The complications occurred in 20 (11.2%) patients from the E-mode group: pancreatitis in 6 (3.4%) and endoscopically evident bleeding in 14 (7.8%). In contrast, the complications occurred in 25 (13.8%) patients from the C-mode group: pancreatitis in 7 (3.9%) and endoscopically evident bleeding in 18 (9.9%), although these findings were not statistically significant. Overall, there were no severe complications. There were no significant differences in completion ratio of EST and the time taken for the sphincterotomy between both groups., Conclusions: The E-mode could not surpass the C-mode in safety and efficacy under the operation by a single endoscopist.

We studied the reproductive biology and adaptability of the alien freshwater crangonyctid amphipod Crangonyx floridanus, currently inhabiting a large portion of Japan, both in the field and under controlled laboratory conditions. In the Chikuma River population of this alien amphipod, egg-bearing individuals were found throughout the year. In terms of egg maturation cycle, egg development (during embryogenesis), and egg count per ovipositional cycle, these amphipods display a very efficient reproductive system. This study also established their adaptability to a wide range of water temperatures (primarily 4-20 degrees C, however in some cases, these individuals are able to survive at up to 30 degrees C). C. floridanus's strong capacity to adapt to broad and variable environmental conditions is certainly contributing to its high rate of population increase, and rapid dispersion throughout Japan.