A novel single-stranded DNA-specific 3′–5′ exonuclease, Thermus thermophilus exonuclease I, is involved in several DNA repair pathways

Single-stranded DNA (ssDNA)-specific exonucleases (ssExos) are expected to be involved in a variety of DNA repair pathways corresponding to their cleavage polarities; however, the relationship between the cleavage polarity and the respective DNA repair pathways is only partially understood. To understand the cellular function of ssExos in DNA repair better, genes encoding ssExos were disrupted in Thermus thermophilus HB8 that seems to have only a single set of 5′–3′ and 3′–5′ ssExos unlike other model organisms. Disruption of the tthb178 gene, which was expected to encode a 3′–5′ ssExo, resulted in significant increase in the sensitivity to H2O2 and frequency of the spontaneous mutation rate, but scarcely affected the sensitivity to ultraviolet (UV) irradiation. In contrast, disruption of the recJ gene, which encodes a 5′–3′ ssExo, showed little effect on the sensitivity to H2O2, but caused increased sensitivity to UV irradiation. In vitro characterization revealed that TTHB178 possessed 3′–5′ ssExo activity that degraded ssDNAs containing deaminated and methylated bases, but not those containing oxidized bases or abasic sites. Consequently, we concluded that TTHB178 is a novel 3′–5′ ssExo that functions in various DNA repair systems in cooperation with or independently of RecJ. We named TTHB178 as T. thermophilus exonuclease I

Creation and application of 250 m square grid meteorological information for crop management using a local weather station network

A method to estimate meteorological factors on a 250 m square grid using real-time data from a local weather station network was developed. The method had better precision than an existing one. The 250 m square grid meteorological information was created to cover Memuro City, Hokkaido. The informa - tion was used with a wheat developmental model to predict the distribution of wheat maturity days in the city, which had 6, 170 ha of wheat fields and 50 combine harvesters, to support decisions for the best management of the harvesters to avoid damage by preharvest sprouting

A series of seton techniques involving “top-down therapy” for patients with Crohn's disease who initially presented with perianal fistulas

Objectives: We determined the outcomes of seton treatment through a series of techniques using biological agents (BIOs) in 18 patients with Crohn's disease (CD) who initially presented with perianal fistulas. Methods: The patients underwent seton drainage using three seton types: a Penrose tube for fistulas with massive purulent discharge, a vessel loop for a small amount of discharge, and a rubber band for unproductive fistulas. If the distal end of the fistula extended more than 4 cm from the anal orifice, the skin and subcutaneous tissue were dissected along the outer edge of the anal sphincter to divide the fistulous tract into two portions. One seton encircled the sphincter from the primary opening throughout the anal canal (medial seton), and the other was inserted through the distal tract outside the sphincter (lateral seton). A BIO was then introduced immediately. When discharge ceased, the Penrose tube or vessel loop was replaced sequentially with a rubber band, which was tied fittingly and subsequently removed in medial to lateral order. Results: The mean interval between fistula onset and CD diagnosis was 2.1 years, and that between CD diagnosis and introduction of BIOs was 0.5 years. The mean follow-up duration was 4 years. The BIOs currently used were infliximab in 10 patients, adalimumab in 7, and ustekinumab in 1. The overall success rate was 94.4%, including unproductive fistulas in 10 (55.6%) patients and fistula disappearance in 7 (38.9%). Conclusions: Our seton drainage techniques via the “top-down” approach represent a promising avenue for treating perianal fistulas in patients with CD

Effects of urbanization, economic development, and migration of workers on suicide mortality in Japan

The relationships between male or female age-adjusted suicide mortality and social life factors for all 47 Japanese prefectures in 1980, 1985 and 1990 were investigated by stepwise multiple regression analysis after classification of 20 social life indicators by factor analysis. During this period, Japan experienced the second economic crisis (the so-called secondary oil crisis) in 1980-1983 and economic prosperity (bubble economy) in 1986-1990. In all the three years, male suicide mortality was significantly related inversely to the urbanization and economic development factor, the result of which was consistent with the data in our previous study for the years 1970 and 1975. Similarly, the male mortality was positively related to the factor of migration of workers in the three years. No factor significantly related to female mortality for all the three years was found. It is suggested that (1) urbanization was a major determinant which prevented male suicide mortality during the past 20 years (1970-1990) in Japan; (2) migration of workers became an important factor for male suicide mortality during these 10 years; and (3) female suicide mortality was less vulnerable to social life factors for these 20 years than the male mortality.Suicide Urbanization Economic development Migration of workers Gender difference Japan