Reevaluation of bactericidal, cytotoxic, and macrophage-stimulating activities of commercially available Fucus vesiculosus fucoidan

Nishiguchi, Tomoki,Jiang, Zedong,Ueno, Mikinori,Takeshita, Satoshi,Cho, Kichul,Roh, Seong Woon,Kang, Kyong-Hwa,Yamaguchi, Kenichi,Kim, Daekyung,Oda, Tatsuya The Korean Society of Phycology 2014 ALGAE Vol.29 No.3

Polysaccharides prepared from marine algae sometimes contain contaminants such as polyphenols and endotoxins that may mislead their bona fide biological activities. In this study, we examined bioactive contaminants in commercially available fucoindan from Fucus vesiculosus, along with ascophyllan and fucoidan from Ascophyllum nodosum. F. vesiculosus fucoidan inhibited the growth of Vibrio alginolyticus in a concentration-dependent manner ($0-1,000{\mu}g\;mL^{-1}$). However, the antibacterial activity of the fucoidan significantly reduced after methanol-extraction, and the methanol-extract showed a potent antibacterial activity. The extract also showed cytotoxicity to RAW264.7 and U937 cells, and induced apoptotic nuclear morphological changes in U937 cells. These results suggest that the antibacterial activity of the fucoidan is partly due to the methanol-extractable contaminants that can also contribute to the cytotoxicity on RAW264.7 and U937 cells. On the other hand, the activities to induce secretion of nitric oxide and tumor necrosis factor-${\alpha}$ from RAW264.7 cells were observed in the fucoidan even after methanol extraction, and the extract had no such activities. Our observations suggest that commercially available fucoidan should be purified prior to biochemical use.

Intracellular haemolytic agents of Heterocapsa circularisquama exhibit toxic effects on H. circularisquama cells themselves and suppress both cell-mediated haemolytic activity and toxicity to rotifers (Brachionus plicatilis)

Nishiguchi, T.,Cho, K.,Yasutomi, M.,Ueno, M.,Yamaguchi, K.,Basti, L.,Yamasaki, Y.,Takeshita, S.,Kim, D.,Oda, T. Elsevier/North Holland Biomedical Press 2016 Aquatic toxicology Vol.179 No.-

<P>A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells. Because H. circularisquama showed similar toxicity to rotifers regardless of the light conditions, and because ultrasonic ruptured H. circularisquama cells showed no significant toxicity to rotifers, it was suggested that live cell-mediated light-independent haemolytic activity is a major factor responsible for the observed toxicity to rotifers. Interestingly, the ultrasonic-ruptured cells of H. circularisquama suppressed their own lethal effect on the rotifers. Analysis of samples of the cell contents (supernatant) and cell fragments (precipitate) prepared from the ruptured H. circularisquama cells indicated that the cell contents contain inhibitors for the light-independent cell-mediated haemolytic activity, toxins affecting H. circularisquama cells themselves, as well as light-dependent haemolytic agents. Ethanol extract prepared from H. circularisquama, which is supposed to contain a porphyrin derivative that displays photosensitising haemolytic activity, showed potent toxicity to Chattonella marina, Chattonella antiqua, and Karenia mikimotoi, as well as to H. circularisquama at the concentration range at which no significant toxicity to rotifers was observed. Analysis on a column of Sephadex LH-20 revealed that light-dependent haemolytic activity and inhibitory activity on cell-mediated light-independent haemolytic activity existed in two separate fractions (f-2 and f-3), suggesting that both activities might be derived from common compounds. Our results suggest that the photosensitising haemolytic toxin discharged from ruptured H. circularisquama cells has a relatively broad spectrum of phytoplankton toxicity, and that physical collapse of H. circularisquama cells can lead not only to the disappearance of its own toxicity, but also to mitigation of the effects of other HABs. (C) 2016 Elsevier B.V. All rights reserved.</P>

Reevaluation of bactericidal, cytotoxic, and macrophage-stimulating activities of commercially available Fucus vesiculosus fucoidan

Tomoki Nishiguchi,Zedong Jiang,Mikinori Ueno,Satoshi Takeshita,Kichul Cho,노성운,Kyong-Hwa Kang,Kenichi Yamaguchi,Daekyung Kim,Tatsuya Oda 한국조류학회I 2014 ALGAE Vol.29 No.3

Polysaccharides prepared from marine algae sometimes contain contaminants such as polyphenols and endotoxins that may mislead their bona fide biological activities. In this study, we examined bioactive contaminants in commercially available fucoindan from Fucus vesiculosus, along with ascophyllan and fucoidan from Ascophyllum nodosum. F. vesiculosus fucoidan inhibited the growth of Vibrio alginolyticus in a concentration-dependent manner (0-1,000 μg mL-1). However, the antibacterial activity of the fucoidan significantly reduced after methanol-extraction, and the methanol-extract showed a potent antibacterial activity. The extract also showed cytotoxicity to RAW264.7 and U937 cells, and induced apoptotic nuclear morphological changes in U937 cells. These results suggest that the antibacterial activity of the fucoidan is partly due to the methanol-extractable contaminants that can also contribute to the cytotoxicity on RAW264.7 and U937 cells. On the other hand, the activities to induce secretion of nitric oxide and tumor necrosis factor-α from RAW264.7 cells were observed in the fucoidan even after methanol extraction, and the extract had no such activities. Our observations suggest that commercially available fucoidan should be purified prior to biochemical use.

Increases in iPS Transcription Factor (Oct4, Sox2, c-Myc, and Klf4) Gene Expression after Modified Electroconvulsive Therapy

Masaki Nishiguchi,Hiroki Kikuyama,Tetsufumi Kanazawa,Atsushi Tsutsumi,Takao Kaneko,Hiroyuki Uenishi,Yasuo Kawabata,Seiya Kawashige,Jun Koh,Hiroshi Yoneda 대한신경정신의학회 2015 PSYCHIATRY INVESTIGATION Vol.12 No.4

ObjectiveaaElectroconvulsive therapy (ECT) is a reasonable option for intractable depression or schizophrenia, but a mechanism of action has not been established. One credible hypothesis is related to neural plasticity. Three genes (Oct4, Sox2, c-Myc) involved in the induction of induced pluripotent stem (iPS) cells are Wnt-target genes, which constitute a key gene group involved in neural plasticity through the TCF family. Klf4 is the other gene among Yamanaka’s four transcription factors, and increases in its expression are induced by stimulation of the canonical Wnt pathway. MethodsaaWe compared the peripheral blood gene expression of the four iPS genes (Oct4, Sox2, c-Myc, and Klf4) before and after modified ECT (specifically ECT with general anesthesia) of patients with intractable depression (n=6) or schizophrenia (n=6). Using Thymatron ten times the total bilateral electrical stimulation was evoked. ResultsaaBoth assessments of the symptoms demonstrated significant improvement after mECT stimulation. Expression of all four genes was confirmed to increase after initial stimulation. The gene expression levels after treatment were significantly different from the initial gene expression in all twelve cases at the following treatment stages: at the 3rd mECT for Oct4; at the 6th and 10th mECT for Sox2; and at the 3rd, 6th and 10th mECT for c-Myc. ConclusionaaThese significant differences were not present after correction for multiple testing; however, our data have the potential to explain the molecular mechanisms of mECT from a unique perspective. Further studie should be conducted to clarify the pathophysiological involvement of iPS-inducing genes in ECT.

A Design of a Gain-Scheduling Controller by Convex optimization Satisfying Robust Performance Condition on the Nyquist Diagram

Yoshitaka Nishiguchi,Kazuhiro Yubai,Junji Hirai 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

This paper presents a new design approach of a gain-scheduling controller using only frequency responses of the plant without any transfer functions or state space representations of the plant. In this paper, the robust performance condition is approximated by convex constraints with respect to the controller parameters on the Nyquist diagram, and controller parameters that satisfy convex constraints are derived by solving convex optimization problem. A gainscheduling controller is linearly parameterized with respect to a controller parameter vector defined as an affine function of the scheduling parameter. Moreover, the proposed method can reduce conservativeness by design of the optimal nominal model from the obtained frequency responses at the prespecified frequency points. The effectiveness of the proposed method is confirmed through the experiments.

New Antiviral Strategies for Hepatitis C

( Shuhei Nishiguchi ) 대한간학회 2007 Clinical and Molecular Hepatology(대한간학회지) Vol.13 No.5(S)

Dynamic Memory Access Control for Accelerating FPGA-based Image Processing

Kenta Nishiguchi,Toshiyuki Inoue,Rei Yamazaki,Kazunori Ogohara,Akira Tsuchiya,Keiji Kishine 대한전자공학회 2021 Journal of semiconductor technology and science Vol.21 No.1

In an FPGA-based image processing system, memory access plays an important role in increasing the speed of image processing. With the conventional method, the memory access interval for image processing was fixed, which limited the processing speed. In this work, we developed a novel memory access method that dynamically controls the intervals between memory access requests for image processing by monitoring the memory status. We implemented an image processing system with the proposed method and examined its characteristics. The maximum processing speed with the proposed method reached 30.7 fps, which was 1.65 times faster than that of the conventional method.

Development Of Entrepreneurs’ Manual For Women

Dr. Mitsuko NISHIGUCHI,Mikiko WATABE,Kunio OHNO 한국직업자격학회 2017 한국직업자격학회 학술대회 Vol.2017 No.10

Increase of women entrepreneurs are expected because it may break through the stagnating local economy and change the society. However, Japanese women are not utilized fully compared with other developed countries since many women have to abandon their career after the birth of children. In another word, there is a lot of potential to use women’s ability in Japan since they may not be utilized fully. The author and her colleagues conducted hearings with women entrepreneurs to know their success factors and surveyed middle aged women in Fukushima to know their entrepreneurial and human resource development needs. Reflecting these, two days seminars for supporting the future women entrepreneurs were held twice in Iwaki city, Fukushima. Finally, a manual which is aiming to support women entrepreneurs was created as a result of the study and continuous blushing up by PDCA should be required in order to support increase of women entrepreneurs.

A Comparative Study of Network Systems Among Korean and Japanese Auto-Parts Suppliers

Kim, Ki Chan,Toshihiro, Nishiguchi,Lynn, Hyung Gu 한국생산성학회 1997 THE JOURNAL OF PRODUCTIVITY Vol.3 No.1

In the present inter-system competition structure, the individual firm can no longer compete as an isolated entity. Previous works have examined network systems and inter-system competition at the macro-level, but in this study, these issues are analyzed at the micro-level. Through a comparative analysis of the network system activities of Korean and Japanese auto-parts manufacturers, some suggestions and conclusions regarding small and medium firms are generated.

Effects of Strains of Saccharomyces cerevisiae and Incubation Conditions on the In vitro Degradability of Yeast and Roughage

Ando, S.,Nishiguchi, Y.,Hayasaka, K.,Yoshihara, Y.,Takahashi, J.,Iefuji, H. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.3

The in vitro degradability of yeast and the effect of yeast on the in vitro degradability of forage may differ in terms of the specific yeast strains or their incubation conditions. Thus in experiment 1, two strains of sake yeast (strainK7 and strainK9) and one strain of bakers' yeast (KY5649) were incubated in an aerobic condition. In experiment 2, aerobically or anaero bically incubated K7 was used for investigating the in vitro degradability of yeast, the effect of yeast on the in vitro degradability of forage, and the degradability of yeast by pepsin and pronase treatment. The in vitrodegradability of bakers' yeast was significantly (p<0.05) higher than those of sake yeasts. The in vitro degradability of anaerobically incubated yeast was significantly (p<0.01) higher than that of aerobically incubated yeast. The degradability of bakers' yeast by pepsin treatment was significantly (p<0.01) higher than that of the sake yeasts. The degradability of bakers' yeast by pronase treatment was slightly higher than that of the two sake yeasts, while the degradability of anaerobically incubated yeast by both enzymes, respectively, was significantly (p<0.01) higher than that of aerobically incubated yeast. The degradability of forages was increased significantly (p<0.05) by the addition of yeasts. The degradability of roughage by sake yeast tended to be higher than that by the bakers' yeast. The degradability of roughage was significantly (p<0.05) higher by anaerobically incubated yeast than by aerobically incubated yeast. Given the above results, it seems that in vitro degradability of yeast and the magnitude of the increment of roughage degradation differ among the yeast strains and their incubation conditions.