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44 results on '"Ishii, Ken-ichiro"'

8. Genome evolution of a nonparasitic secondary heterotroph, the diatom Nitzschia putrida

Author

Kamikawa, Ryoma, primary, Mochizuki, Takako, additional, Sakamoto, Mika, additional, Tanizawa, Yasuhiro, additional, Nakayama, Takuro, additional, Onuma, Ryo, additional, Cenci, Ugo, additional, Moog, Daniel, additional, Speak, Samuel, additional, Sarkozi, Krisztina, additional, Toseland, Andrew, additional, van Oosterhout, Cock, additional, Oyama, Kaori, additional, Kato, Misako, additional, Kume, Keitaro, additional, Kayama, Motoki, additional, Azuma, Tomonori, additional, Ishii, Ken-ichiro, additional, Miyashita, Hideaki, additional, Henrissat, Bernard, additional, Lombard, Vincent, additional, Win, Joe, additional, Kamoun, Sophien, additional, Kashiyama, Yuichiro, additional, Mayama, Shigeki, additional, Miyagishima, Shin-ya, additional, Tanifuji, Goro, additional, Mock, Thomas, additional, and Nakamura, Yasukazu, additional

Published
2022
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13. Different Nutrient Availabilities of Surface and Bottom Water under Nutrient-depleted Conditions during Bloom Formation of the Toxic Dinoflagellate Alexandrium tamarense in Osaka Bay, Japan

Author

Natsuike, Masafumi, Shiraishi, Tomotaka, Ishii, Ken-Ichiro, Yamamoto, Keigo, Nakajima, Masaki, Sawayama, Shigeki, and Imai, Ichiro

Subjects
Bioavaiilability, Algal growth potential, Osaka Bay, Limiting, Skeletonema, Nutrients, Alexandrium tamarense
Abstract

Alexandriium tamarense is a toxic dinoflagellate known to produce neurotoxins cause paralytic shellfish poisoning to human and marine animals. To understand the growth dynamics of A.tamarense, the seasonal changes in A,tamarense vegetative cells and environmental factors were evaluated using monthly field observations at two fixed stations in Osaka Bay, Japan, from January to May 2008. Additionally, a bioassay with axenic A.tamarense clonal cultures was performed to determine the growth potentials and growth-limiting nutrients of seawater samples collected during the field observations. The density of A.tamarense increased from February to April, and depletions of dissolved phosphate and silicate were observed in the surface layer during this period. The bioassay showed that phosphorous limitation occurred at the surface water of one station during March and April, while nitrogen limitation occurred in the bottom water. Moreover, at the other station, the growth potentials of the bottom water were higher than those of the surface water during February and April. Thus, the differences of nutrient availabilities between surface and bottom water during spring in Osaka Bay potentially allow A.tamarense to grow with nutrients uptake from bottom water by vertical migration.

Published
2018

14. Genome evolution of a non-parasitic secondary heterotroph, the diatom Nitzschia putrida

Author

Kamikawa, Ryoma, primary, Mochizuki, Takako, additional, Sakamoto, Mika, additional, Tanizawa, Yasuhiro, additional, Nakayama, Takuro, additional, Onuma, Ryo, additional, Cenci, Ugo, additional, Moog, Daniel, additional, Speak, Samuel, additional, Sarkozi, Krisztina, additional, Toseland, Andrew, additional, van Oosterhout, Cock, additional, Oyama, Kaori, additional, Kato, Misako, additional, Kume, Keitaro, additional, Kayama, Motoki, additional, Azuma, Tomonori, additional, Ishii, Ken-ichiro, additional, Miyashita, Hideaki, additional, Henrissat, Bernard, additional, Lombard, Vincent, additional, Win, Joe, additional, Kamoun, Sophien, additional, Kashiyama, Yuichiro, additional, Mayama, Shigeki, additional, Miyagishima, Shin-ya, additional, Tanifuji, Goro, additional, Mock, Thomas, additional, and Nakamura, Yasukazu, additional

Published
2021
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19. Short-term changes in planktonic community of the western subarctic Pacific during early summer : analysis of sediment trap samples

Author

Ohashi, Rie, Ishii, Ken-ichiro, Fujiki, Tetsuichi, Kitamura, Minoru, Matsumoto, Kazuhiko, Honda, Makio C., and Yamaguchi, Atsushi

Subjects
Western subarctic Pacific, Sediment trap, Sagitta elegans, Eucalanus bungii, Short-term changes
Abstract

To evaluate short-term changes in planktonic community, we analysed phytoplankton and zooplankton collected by a sediment trap moored at 150 m of St. K2 (47°N, 160°E) in the western subarctic Pacific with precision of two-day interval during 7 June to 1 July 2006. Phytoplankton flux varied from 480 to 372,290 cells m^-2 day^-1, and had a peak in 17-19 June. Phytoplankton community was composed of five diatom species and one silicoflagellate species. From Bray-Curtis cluster analysis, phytoplankton communities were classified into four groups. Zooplankton abundance ranged from 1,137 to 3,385 inds. m^-2 day^-1 and showed two peaks in 13-15 June and 21-23 June. Throughout the study period, large copepod Eucalanus bungii accounted 50-90% of total zooplankton abundance. Gonad maturation of adult females of E. bungii advanced during the study period: immature occurred before 15 June, developed during 19-27 June and newly recruited specimens to adult females were observed after 25 June. As carnivorous zooplankton, chaetognath community was predominated by Sagitta elegans (99.7% of total abundance). Body length of S. elegans ranged 22-39 mm, and the mean body length gradually increased during the study period (0.21 mm per day, r^2=0.72, p

Published
2011

38. Proposal of identification criteria for resting spores of species (Bacillariophyceae) from a temperate coastal sea.

Author

Ishii, Ken-ichiro, Iwataki, Mitsunori, Matsuoka, Kazumi, and Imai, Ichiro

Subjects
*DIATOMS, *SPORES, *ANIMAL morphology, MICROORGANISM identification
Abstract

I shii K.-I., I wataki M., M atsuoka K. and I mai I. 2011. Proposal of identification criteria for resting spores of species (Bacillariophyceae) from a temperate coastal sea. 50: 351--362. DOI: 10.2216/10-36.1 is a large, ecologically important genus of marine planktonic diatoms. Many species of form resting spores to survive environmental stress. Species identification based on morphological characteristics of resting spores is difficult. In the present study, we proposed a flow diagram for the identification of species based on morphology. Resting spores of 18 species were identified in water and sediment samples from southern Japan and the East China Sea based on morphological characteristics of resting spores and/or the vegetative cells containing them. A single ring of puncta was found to be the most important morphological feature of resting spores for species identification, by which the positions of primary and secondary valves were correctly determined. Other morphological characteristics such as features of the primary valve face, margins of the primary and secondary valve mantles, and secondary valve face are also useful for species identification. A combination of these morphological characteristics was used to construct a flow diagram for identification of the 18 species found in our samples with light microscopy. This flow diagram is most applicable to Japanese waters, but the approach should be refined and improved to understand the biology and ecology of species in any marine ecosystem. [ABSTRACT FROM AUTHOR]

Published
2011
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41. Proposal of identification criteria for resting spores of Chaetocerosspecies (Bacillariophyceae) from a temperate coastal sea

Author

Ishii, Ken-ichiro, Iwataki, Mitsunori, Matsuoka, Kazumi, and Imai, Ichiro

Abstract

IshiiK.-I., IwatakiM., MatsuokaK. andImaiI. 2011. Proposal of identification criteria for resting spores of Chaetocerosspecies (Bacillariophyceae) from a temperate coastal sea. Phycologia50: 351–362. DOI: 10.2216/10-36.1Chaetocerosis a large, ecologically important genus of marine planktonic diatoms. Many species of Chaetocerosform resting spores to survive environmental stress. Species identification based on morphological characteristics of resting spores is difficult. In the present study, we proposed a flow diagram for the identification of Chaetocerosspecies based on morphology. Resting spores of 18 Chaetocerosspecies were identified in water and sediment samples from southern Japan and the East China Sea based on morphological characteristics of resting spores and/or the vegetative cells containing them. A single ring of puncta was found to be the most important morphological feature of resting spores for species identification, by which the positions of primary and secondary valves were correctly determined. Other morphological characteristics such as features of the primary valve face, margins of the primary and secondary valve mantles, and secondary valve face are also useful for species identification. A combination of these morphological characteristics was used to construct a flow diagram for identification of the 18 Chaetocerosspecies found in our samples with light microscopy. This flow diagram is most applicable to Japanese waters, but the approach should be refined and improved to understand the biology and ecology of Chaetocerosspecies in any marine ecosystem.

Published
2011
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44. Effect of FR167653, a novel inhibitor of tumor necrosis factor-alpha and interleukin-1beta synthesis on lipopolysaccharide-induced hepatic microvascular dysfunction in mice.

Author

Matsumoto Y, Ito Y, Hayashi I, Majima M, Ishii K, Katagiri H, and Kakita A

Subjects
Animals, Endotoxemia drug therapy, Endotoxemia physiopathology, Interleukin-1 antagonists & inhibitors, Interleukin-1 pharmacology, Leukocytes pathology, Lipopolysaccharides, Liver drug effects, Liver pathology, Male, Mice, Mice, Inbred Strains, Tumor Necrosis Factor-alpha antagonists & inhibitors, Tumor Necrosis Factor-alpha pharmacology, Interleukin-1 biosynthesis, Liver blood supply, Microcirculation drug effects, Protein Synthesis Inhibitors pharmacology, Pyrazoles pharmacology, Pyridines pharmacology, Tumor Necrosis Factor-alpha biosynthesis
Abstract

Tumor necrosis factor-alpha (TNFalpha) and interleukin-1 (IL-1) have been recognized as key proinflammatory mediators in the pathogenesis of lipopolysaccharide (LPS)-induced liver injury. In the present study we examined the effect of FR167653, a novel inhibitor of TNFalpha and IL-1 synthesis, on the hepatic microvascular response to LPS using in vivo microscopy. Significant hepatic microvascular responses comprising leukocyte adhesion to the sinusoidal wall and central venules and reduced sinusoidal perfusion appeared 2 and 4 h after LPS (0.1 mg/kg, i.v.) injection in male C3H/HeN mice (LPS sensitive) when compared with male C3H/HeJ mice (LPS resistant). The serum concentrations of TNFalpha at 1.5 h and IL-1beta at 4 h after injection of LPS, as determined by enzyme-linked immunosorbent assay, were significantly higher in C3H/HeN mice than in C3H/HeJ mice. Administration of murine TNFalpha or IL-1beta (10 microg/kg., i.v., respectively) in both C3H/HeN and C3H/HeJ mice elicited the hepatic microvascular responses that were similar to those produced by LPS injection in C3H/HeN mice. FR167653 (1 and 10 mg/kg, i.v., 0 and 2 h after LPS injection) significantly reduced leukocyte adhesion and restored sinusoidal perfusion in a dose-dependent manner in C3H/HeN mice 4 h after LPS injection. The levels of TNFalpha, IL-1beta, and alanine aminotransferase also were significantly lower in FR167653-treated endotoxemic C3H/HeN mice than those in vehicle-treated endotoxemic animals. The results suggest that the hepatic microvascular response to LPS is partly mediated by TNFalpha and IL-1beta, and that FR167653 prevents LPS-induced hepatic microcirculatory dysfunction by inhibiting the production of TNFalpha and IL-1beta.

Published
2002
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