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971.
Takahiro Asami Makoto Ishii Ho Namkoong Kazuma Yagi Sadatomo Tasaka Takanori Asakura Shoji Suzuki Tetsuro Kamo Satoshi Okamori Hirofumi Kamata Haiyue Zhang Ahmed E. Hegab Naoki Hasegawa Tomoko Betsuyaku 《Cytotherapy》2018,20(3):302-313
Background
Pneumonia is the fourth leading cause of death worldwide, and Streptococcus pneumoniae is the most commonly associated pathogen. Increasing evidence suggests that mesenchymal stromal cells (MSCs) have anti-inflammatory roles during innate immune responses such as sepsis. However, little is known about the effect of MSCs on pneumococcal pneumonia.Methods
Bone marrow–derived macrophages (BMDMs) were stimulated with various ligands in the presence or absence of MSC-conditioned medium. For in vivo studies, mice intranasally-inoculated with S. pneumoniae were intravenously treated with MSCs or vehicle, and various parameters were assessed.Results
After stimulation with toll-like receptor (TLR) 2, TLR9 or TLR4 ligands, or live S. pneumoniae, TNF-α and interleukin (IL)–6 levels were significantly decreased, whereas IL-10 was significantly increased in BMDMs cultured in MSC-conditioned medium. In mice, MSC treatment decreased the number of neutrophils in bronchoalveolar lavage fluid (BALF) after pneumococcal infection, and this was associated with a decrease in myeloperoxidase activity in the lungs. Levels of proinflammatory cytokines, including TNF-α, IL-6, GM-CSF and IFN-γ, were significantly lower in MSC-treated mice, and the bacterial load in the lung after pneumococcal infection was significantly reduced. In addition, histopathologic analysis confirmed a decrease in the number of cells recruited to the lungs; however, lung edema, protein leakage into the BALF and levels of the antibacterial protein lipocalin 2 in the BALF were comparable between the groups.Conclusions
These results indicate that MSCs could represent a potential therapeutic application for the treatment of pneumonia caused by S. pneumoniae. 相似文献972.
The gain of foldable wings is regarded as one of the key innovations enabling the present-day diversity of neopteran insects. Wing folding allows compact housing of the wings and shields the insect body from damage. Wing-fixing systems have evolved in some insects, probably to increase the durability of the shielding function by the wings. Bark lice (Psocodea) are known to possess a unique wing-to-wing repose coupling system, but a detailed morphological and evolutionary study of this system is lacking. In this study, we examined this repose coupling structure by SEM in 32 species including representatives of all three suborders of bark lice (Trogiomorpha, Troctomorpha and Psocomorpha). We concluded that the repose wing-coupling apparatus independently evolved twice within Psocodea. In Trogiomorpha, the apparatus is located on the subcostal vein of the forewing and is composed of elongated rib-like structures. In Troctomorpha and Psocomorpha, in contrast, the repose coupling structure is located on the radius vein of the forewing and is formed by a swollen vein. These morphological and developmental differences in the repose coupling structures also provide phylogenetic information at different systematic levels. 相似文献
973.
Densification of cyanobacteria from a lake leading to production of β‐cyclocitral and related volatile organic compounds and species change
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Suzue Arii Kiyomi Tsuji Koji Tomita Masateru Hasegawa Ryuji Yamashita Beata Bober Ken‐Ichi Harada 《Phycological Research》2018,66(3):161-166
The purpose of the present study was to demonstrate that the lysis with the blue color formation was caused by densification of the cyanobacteria, and related events of the species change in the cyanobacteria were induced by the resulting volatile organic compounds (VOCs), particularly β‐cyclocitral. In order to obtain a high cell density of cyanobacteria in the laboratory, a concentration technique (graduated cylinder method) using the buoyancy of the gas vesicles was successfully used. The collected scum contained mainly Dolichospermum spp. and Microcystis, and the dispersed cyanobacteria were concentrated in the surface layer after several hours and the concentration ratio became approximately 10. The concentrated cyanobacteria were gradually lysed, while some of the cyanobacteria sank to the bottom, which finally died and disappeared. This method has the additional advantage that it is possible to visualize the entire lysis process. During the concentration process, β‐cyclocitral and its oxidation products together with β‐ionone were significantly detected. Because β‐cyclocitral was easily oxidized to the corresponding carboxylic acid, the pH of the water in the graduated cylinder decreased to approximately 6. Under favorable conditions, lysis with the blue color from phycocyanin could be observed due to the acid stress. Overall, the results of the present study were consistent with the hypothesis that VOCs were produced when the cyanobacteria are highly dense, and that the lysis with the blue color formation occurs due to the higher density. 相似文献
974.
The Japanese golden chanterelle commonly identified as Cantharellus cibarius was sampled in a broad range of forest vegetation. A total of 90 fresh and 11 herbarium specimens were examined microscopically, subjected to sequencing analysis of their nuclear ribosomal RNA (rDNA) and tef-1 genes, and their characteristics were compared with those of European C. cibarius. Based on morphological and ecological characteristics, basidioma samples from Japan were divided into four species. While specimens of Cantharellus sp. 4 from Hokkaido Island were included in the European C. cibarius clade phylogenetically, the other three species formed three unique clades. Among these, Cantharellus anzutake sp. nov. is sister to the clade of C. cibarius and was widely sampled from the northern limit of Honshu Island to the southern limit of Kumejima Island in Ryukyu Islands. Although C. anzutake was morphologically similar to C. cibarius, the two species were phylogenetically distinct. Other morphologically similar but genetically distinct chanterelle species from India exhibited macroscopic and microscopic differences compared with C. anzutake. 相似文献
975.
Broad infectivity of Leidynema appendiculatum (Nematoda: Oxyurida: Thelastomatidae) parasite of the smokybrown cockroach Periplaneta fuliginosa (Blattodea: Blattidae)
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Host specificity of parasites is important for the understanding of evolutionary strategies of parasitism that would be a basis of predictions of the disease expansion when parasitized hosts invade new environments. The nematode order Oxyurida is an interesting parasite group for studying the evolution of parasitism as it includes parasites of both invertebrates and vertebrates. In our survey, we found that the smokybrown cockroach Periplaneta fuliginosa was primarily infected with only one nematode species Leidynema appendiculatum. In two cases, L. appendiculatum was isolated from two additional cockroach species Pycnoscelus surinamensis, sold in Japan as a reptile food, and Blatta lateralis, captured in the field and cultured in the laboratory. Inoculation of L. appendiculatum into three additional cockroach species P. japonica, Blattella nipponica, and P. surinamensis also resulted in parasitism. Infection prevalence was high, and timing of postembryonic development from hatched nematode larva to mature adult in these hosts was identical with that in P. fuliginosa. While ecological interactions strongly determine the host range, such broad infectivity is still possible in this parasitic nematode. 相似文献
976.
Yoichiro Fujioka Shinya Nishide Toyoyuki Ose Tadaki Suzuki Izumi Kato Hideo Fukuhara Mari Fujioka Kosui Horiuchi Aya O. Satoh Prabha Nepal Sayaka Kashiwagi Jing Wang Mika Horiguchi Yuko Sato Sarad Paudel Asuka Nanbo Tadaaki Miyazaki Hideki Hasegawa Yusuke Ohba 《Cell host & microbe》2018,23(6):809-818.e5
977.
Hiroshi Hasegawa Ayumi Nozawa Rimana Islam Papry Teruya Maki Osamu Miki M. Azizur Rahman 《Journal of applied phycology》2018,30(4):2215-2225
Iron (Fe) is an important nutrient for phytoplankton. The low solubility of Fe in oxic waters can be a growth-limiting factor for phytoplankton. Synthetic aminopolycarboxylates (APCs) such as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) are widely used as Fe complexing agents for microalgae culture. However, the presence of these non-ready biodegradable APCS in aquatic systems may have serious environmental consequences. In the present study, the effects of biodegradable chelating ligands (hydroxyiminodisuccinic acid (HIDS), methylglycinediacetic acid (MGDA), and iminodisuccinate (IDS)) on Fe uptake in and growth of three coastal microalgae (Heterosigma akashiwo, Prymnesium parvum, and Skeletonema marinoi-dohrnii complex) were investigated, and the results were compared with those of non-ready biodegradable APCs (EDTA, ethylenediamine tetra-methylene phosphonic acid (EDTMP), and DTPA). The biodegradable chelating ligands did not have significant growth inhibition effect on the phytoplankton. Although the growth of the algae (except S. marinoi-dohrnii complex) was not affected substantially by 1.5 and 7.5 μM of DTPA, growth inhibition occurred by 7.5 μM of EDTMP and 150 μM of EDTA, DTPA, and EDTMP. The effect of chelating ligands on microalgal growth was likely to be associated with the intracellular Fe uptake influenced by the chelating ligands. On average, intracellular Fe concentrations for biodegradable chelating ligands were substantially higher than those for non-ready biodegradable APCs. Except H. akashiwo, the ratio of intra/extracellular Fe concentrations was highest for MGDA followed by IDS and HIDS. The results indicate that biodegradable chelating ligands are more efficient than non-ready biodegradable APCs in intracellular Fe uptake and algal growth. 相似文献
978.
K. Hasegawa Y. Tsukahara M. Shimamoto K. Matsumoto Y. Nakaoka T. Sato 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,181(1):41-46
The behavior of a ciliate protozoan, Paramecium, is known to represent the electrical state of the cell membrane, and regulation of the membrane potential and ciliary motion
are known to involve cAMP and cGMP. The present study shows the synchrony of circadian changes in motility, resting membrane
potential and cyclic nucleotides in P. multimicronucleatum. Using an automated system for tracking isolated single microorganisms, the isolated Paramecium cells are confirmed to swim fast and straight during the day (and subjective day) and slowly, with frequent turning, at night
(and subjective night). The resting membrane potential is more negative during the day than at night. cAMP and cGMP concentrations
oscillate in a manner, such that both cAMP and cGMP are higher during the day (or subjective day) than at night (or subjective
night). The ratio of cGMP to cAMP during the light and dark cycle (LD) fluctuates, paralleling the fluctuation of the resting
membrane potential measured during the LD. These results suggest that the Paramecium will provide an excellent model to explore daily and circadian orchestration of second messengers mediating signals from
ambient light/dark cycles and circadian pacemaker to ion channels and cilia, directly involved in daily and circadian cellular
outputs of resting membrane potential and motility.
Accepted: 23 January 1997 相似文献
979.
Ryotaro Yoshida Akihiro Matsuura Kuniko Einaga Yumiko Ushio Naoki Yamamoto Yukio Yoneda 《Microbiology and immunology》1997,41(2):149-159
It has been reported that the rejection of tumor allografts is mainly mediated by cytotoxic T lymphocytes (CTLs). Here, we characterized the cytotoxic effector cells of C57BL/6 (B6; H-2b) mice infiltrating into the rejection site of the i.p. allografted Meth A fibrosarcoma (or P815 mastocytoma) cells of H-2d origin. Two types of cytotoxic cells (i.e., CD8+ CTLs and macrophages (Mφs)) were identified by flow cytometric fractionation of the infiltrates or by specific in vitro elimination of cells either with antibody (Ab)-coated beads or with an Ab-plus complement. Of particular interest, these effector cells showed distinct and unique target specificities. First, the CTLs were inactive against transplanted tumor (e.g., Meth A) cells, whereas they were cytotoxic against donor-related concanavalin A (Con A) blasts as well as CTLL-2 (H-2b) cells transfected with a class I gene of H-2d origin. A cold target competition assay suggested that the CTLs were composed of multiple sets of T cells, each of which specifically recognized different allo-antigens. Second, the Mφs lysed the allografted tumor cells but were inert toward the Con A blasts and the CTLL-2 transfectants. Unexpectedly, the infiltration of Mφs preceded the infiltration of CTLs by several days during the course of rejection. These results indicate that two distinct populations of unique cytotoxic cells (i.e., CTLs and Mφs) are induced in the allografted tumor rejection site, and that the infiltration of cytotoxic Mφs responsible for rejection precedes that of the CTLs cytotoxic against cells expressing donor-related allo-antigens. 相似文献
980.
Nanako Takeda-Hirokawa Lian-pin Neoh Hiroaki Akimoto Hiroshi Kaneko Takashi Hishikawa Iwao Sekigawa Hiroshi Hashimoto Shun-ichi Hirose Tsutomu Murakami Naoki Yamamoto Tohru Mimura Yutaro Kaneko 《Microbiology and immunology》1997,41(9):741-745
To clarify the mechanism by which curdlan sulfate (CRDS) inhibits human immunodeficiency virus (HIV)-1 infection, we examined its influence on the binding of gp120 to CD4 molecules on T cells and macrophages, as well as on the production of TNF-α by gp120-stimulated macrophages (which promotes HIV-1 replication). CRDS treatment of cells not only inhibited the binding of HIV-1 gp120 to CD4+ cells, but also inhibited TNF-α production induced by gp120. Inhibition of HIV-1 infection by CRDS may be related to these two actions. 相似文献