著者

Kanchi Ito Yuki Osawa Kenta Kaneko Yutaka Kikuchi Masato Odagaki

出版者

一般社団法人日本生体医工学会

雑誌

Advanced Biomedical Engineering (ISSN:21875219)

巻号頁・発行日

vol.6, pp.42-47, 2017 (Released:2017-04-03)

参考文献数

10

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Two different experiments utilizing the motor imagery of finger movement were conducted. We attempted to reveal the difference in corticospinal excitability between tonic contraction (TC) and rhythmic movement (RM) by transcranial magnetic stimulation (TMS). The magnetic coil was placed over the subject’s primary motor cortex to elicit motor-evoked potentials (MEPs) by TMS. We have previously shown that the MEP amplitude is modulated by the frequency of active and passive finger movements. We hypothesized that visual feedback affects the corticospinal excitability. In the present study, the subject observed both TCs and RMs, and the MEP amplitudes elicited by TMS during both tasks were analyzed to assess changes in corticospinal excitability influenced by the motor imagery. A mirror box was used to show the subject the finger movement executed by a third person as if it were his own finger movement. For the TC task, the third person performed a pinching task consisting of TC of the index finger and thumb. The subject received visual feedback of the TC in the mirror. For the RM task, the subject observed the mirror while the third person performed RM of the index finger until TMS was applied. The frequencies of finger movement were 0.5, 1, 2, 3, and 4 Hz. The resulting MEP amplitudes for the RM task at movement frequencies of 2, 3, and 4 Hz were significantly lower than that for the TC task. These results indicate that corticospinal excitability is increased by visual feedback of TC but is modulated by that of RM.

著者

Masaki Shirai Takuya Nara Haruko Takahashi Kazuya Takayama Yuan Chen Yudai Hirose Masashi Fujii Akinori Awazu Nobuyoshi Shimoda Yutaka Kikuchi

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.21-00092, (Released:2022-06-18)

参考文献数

42

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CpG methylation of genomic DNA is a well-known repressive epigenetic marker in eukaryotic transcription, and DNA methylation of promoter regions is correlated with gene silencing. In contrast to the promoter regions, the function of DNA methylation during transcription termination remains to be elucidated. A recent study revealed that mouse DNA methyltransferase 3a (Dnmt3a) mainly functions in de novo methylation in the promoter and gene body regions, including transcription termination sites (TTSs), during development. To investigate the relationship between DNA methylation overlapping the TTSs and transcription termination, we performed bioinformatics analysis using six pre-existing Dnmt-/- mouse cell datasets: four types of neurons (three Dnmt3a-/- and one Dnmt1-/- mutants) and two types of embryonic fibroblasts (MEFs) (Dnmt3a-/- and Dnmt3b-/- mutants). Combined analyses using methylome and transcriptome data revealed that read counts downstream of hypomethylated TTSs were increased in three types of neurons (two Dnmt3a-/- and one Dnmt1-/- mutants). Among these, an increase in chimeric transcripts downstream of the TTSs was observed in Dnmt3a-/- mature olfactory sensory neurons and Dnmt3a-/- agouti-related peptide (protein)-producing neurons, thereby indicating that read-through occurs in hypomethylated TTSs at specific gene loci in these two mutants. Conversely, in Dnmt3a-/- MEFs, we detected reductions in read counts downstream of hypomethylated TTSs. These results indicate that the hypomethylation of TTSs can both positively and negatively regulate transcription termination, dependent on Dnmt and cell types. This study is the first to identify the aberrant termination of transcription at specific gene loci with DNA hypomethylated TTSs attributable to Dnmt deficiency.

著者

Takayuki Sakamoto Motoyasu Ochi Yutaka Kikuchi Kyo Kobayashi Toru Tanaka Yukio Ozaki

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.MI-081, (Released:2016-05-12)

被引用文献数

2

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Harvesting of asparagus spears is hard work because farmers have to harvest spears in a crouching posture. We previously developed electric long-shafted shears and a large-wheeled cart to improve the harvest posture, and we reported that the visibility of spears can be improved by modified branch training using string, without any yield or quality reduction. In the present study, we investigated the harvest efficiency, harvest posture, and subjective burden with electric long-shafted shears and a large-wheeled cart under modified branch training methods (the new standing harvest method) for labor-saving asparagus spear harvesting. Two male subjects in their 30s and 60s harvested spears for 60 min using (standing harvest) and without using (control) the new standing harvest method. The harvest efficiency of the new standing harvest method was 18% lower than that of the control. In the standing harvest, subjects had to pull the shears up to take the harvested spear from the shears with their left hand after each spear was cut (“take”). The subjects needed time for the “take” action, and the time necessary to harvest a spear with the electric long-shafted shears was longer than that required for the control. We also evaluated the harvest posture using the Ovako Working Posture Analyzing System (OWAS). For the subject in his 30s, action category(AC)2 and AC3 accounted for 72% and 14% of the postures recorded in the control, respectively, whereas in the standing harvest, AC1 and AC2 accounted for 57% and 41%, respectively. For the subject in his 60s, AC2 and AC3 accounted for 41% and 58% of the postures recorded in the control, respectively, whereas in the standing harvest, AC1 and AC2 accounted for 27% and 70%, respectively. Unfavorable postures during harvest were reduced by the new standing harvest method. The subjective physical burden on the subjects was evaluated using a modified Borg scale after 60 min of harvesting using and without using the new standing harvest method. The subjective physical burden in both subjects was highest (> 8) at the waist in the control, whereas the scores were lower than 3 in the standing harvest. Thus, the new standing harvest method reduced harvest efficiency, but resulted in substantial improvements in posture and reduced the physical burden on the subjects.