Studies on the Essential Oils of Tobacco Leaves

The basic fraction contained in the essential oil of the Japanese Flue Cured Tobacco Leaf (before redrying) was investigated and 2,3′-dipyridyl was isolated and identified. While, on the other hand, the basic fraction of the essential oil of the aged Japanese Burley Tobacco Leaf was also investigated and nicotine was found to be the predominant constituent of that fraction. At the same time, a small amount of 2,3′-dipyridyl and myosmine was also isolated and identified.     

Effects of dietary di(2-ethylhexyl)phthalate on the metabolism of tryptophan to niacin in mice.

We have reported the effect of di(2-ethylhexyl)phthalate (DEHP) on the tryptophan (Trp)-niacin pathway in rats. To clarify the universal effect of DEHP on rodents, we studied whether DEHP also has an effect on Trp metabolism in mice. Mice were fed a niacin-free, 20% casein diet supplemented with DEHP for 21 days. Feeding with DEHP decreased the body weight gain and increased the liver weight in correlation with the dose level of DEHP. The administration of DEHP significantly increased the formation of quinolinic acid and the lower metabolites of the Trp-niacin pathway. The flux of niacin in the lower part of the Trp-niacin pathway in mice was enhanced by feeding with DEHP.     

Enzymatic Decolorization of Melanoidin by Coriolus sp. No. 20

Coriolus sp. No. 20 decolorized a melanoidin solution, a decrease of about 80% in darkness under the optimal conditions. This decolorization occurred with an intracellular enzyme which was prepared from an extract of integrated mycelia, and required aeration and some kinds of sugars, particularly glucose and sorbose. The fraction with melanoidin-decolorizing activity was collected and purified by DEAE-cellulose and Sephadex G-200 column chromatographies. The optimal pH and temperature were pH 4.5 and 35°C, respectively. The molecular weight was found to be about 200,000 by SDS-gel electrophoresis. The purified enzyme was identified as sorbose oxidase; decolorization proceeded in the presence of oxygen and sugars such as maltose, sucrose, lactose, galactose and xylose, besides glucose and sorbose. Glucose in the reaction mixture was converted to gluconic acid. Melanoidin was suggested to be decolorized by the active oxygen formed.     

Factors Associated with Nurses’ Intention to Leave Their Jobs after the Fukushima Daiichi Nuclear Power Plant Accident

We conducted a survey among nurses who were working at the Fukushima Medical University Hospital at the time of the Fukushima Daiichi Nuclear Power Plant accident to clarify the factors associated with their intention to leave their jobs during the radiation emergency. We asked 345 nurses (17 men and 328 women) about their intention to leave their jobs after the accident. We also asked about relevant factors including the participants’ demographic factors, living situation, working status, and knowledge of radiation health effects. We found that living with preschoolers (OR = 1.87, 95%CI: 1.02–3.44, p = 0.042), anxiety about life in Fukushima City after the accident (OR = 5.55, 95%CI: 1.18–26.13, p = 0.030), consideration of evacuation from Fukushima after the accident (OR = 2.42, 95%CI: 1.45–4.06, p = 0.001), consideration of the possible radiation health effects in children (OR = 1.90, 95%CI: 1.02–3.44, p = 0.042), and anxiety about relationships with colleagues in the hospital after the accident (OR = 3.23, p = 0.001) were independently associated with the nurses’ intention to leave their jobs after the accident. On the other hand, the percentage of nurses with knowledge on radiation health effects was relatively low among those who had the intention to leave the job and among those who did not have the intention to leave the job after the accident, with no significant differences between the two groups. Our results suggest the need for an education program for nurses regarding radiation health effects.     

A thiostrepton resistance gene and its mutants serve as selectable markers in Geobacillus kaustophilus HTA426

Effective utilization of microbes often requires complex genetic modification using multiple antibiotic resistance markers. Because a few markers have been used in Geobacillus spp., the present study was designed to identify a new marker for these thermophiles. We explored antibiotic resistance genes functional in Geobacillus kaustophilus HTA426 and identified a thiostrepton resistance gene (tsr) effective at 50 °C. The tsr gene was further used to generate the mutant tsr^H258Y functional at 55 °C. Higher functional temperature of the mutant was attributable to the increase in thermostability of the gene product because recombinant protein produced from tsr^H258Y was more thermostable than that from tsr. In fact, the tsr^H258Y gene served as a selectable marker for plasmid transformation of G. kaustophilus. This new marker could facilitate complex genetic modification of G. kaustophilus and potentially other Geobacillus spp.     

Scrub typhus caused by Shimokoshi type Orientia tsutsugamushi showing variant 56‐kDa type‐specific antigen gene sequence in Tohoku region,Japan

In 2018, a patient was diagnosed with Shimokoshi type scrub typhus in Yamagata Prefecture, Japan. The causative pathogen was likely a variant type because 43 (8.3%) of 521 deduced amino acid sequences of the 56‐kDa type‐specific antigen (TSA) were different from those of the Shimokoshi prototype strain. The patient's paired sera showed low antibody titers against the Shimokoshi prototype strain. Two cases of scrub typhus reported in the Tohoku region during 2011–2012 also involved the same 56‐kDa TSA gene sequence. These findings suggest the presence of diversity in Shimokoshi type Orientia tsutsugamushi, which may impede the laboratory diagnosis of scrub typhus.     

Effects of CaCl2-washing on EPR Signals of Cytochrome b559 in Photosystem II Preparation from Spinach Chloroplasts

Washing of PS II preparation by 1 M CaCl₂ inactivates oxygenevolution without loss of bound manganese [Ono and Inoue (1983)FEBS Lett. 164: 255]. Most of the high-potential Cyt b₅₅₀, whichamounts to about a half of the total Cyt b₅₅₉ in untreated preparation,was converted to its low-potential form by CaCl₂-washing. Theeffect was similar to that of Tris-washing. The peak positionof the g_s band of the EPR spectrum of the CaCl₂-washed preparation(g=2.95) was the same as that of the low potential form of untreatedpreparation but was slightly different from that of the Tris-washedor heat-treated preparation (g=2.98). ¹ Present address: Department of Biology, Faculty of Science,Tokyo Metropolitan University, Fukazawa 2-1-1, Setagaya, Tokyo158, Japan. (Received November 14, 1984; Accepted January 30, 1985)