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Search Results: 1 - 10 of 2010 matches for " Shinya Ueda "
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A Comparison of Facial Color Pattern and Gazing Behavior in Canid Species Suggests Gaze Communication in Gray Wolves (Canis lupus)
Sayoko Ueda, Gaku Kumagai, Yusuke Otaki, Shinya Yamaguchi, Shiro Kohshima
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0098217
Abstract: As facial color pattern around the eyes has been suggested to serve various adaptive functions related to the gaze signal, we compared the patterns among 25 canid species, focusing on the gaze signal, to estimate the function of facial color pattern in these species. The facial color patterns of the studied species could be categorized into the following three types based on contrast indices relating to the gaze signal: A-type (both pupil position in the eye outline and eye position in the face are clear), B-type (only the eye position is clear), and C-type (both the pupil and eye position are unclear). A-type faces with light-colored irises were observed in most studied species of the wolf-like clade and some of the red fox-like clade. A-type faces tended to be observed in species living in family groups all year-round, whereas B-type faces tended to be seen in solo/pair-living species. The duration of gazing behavior during which the facial gaze-signal is displayed to the other individual was longest in gray wolves with typical A-type faces, of intermediate length in fennec foxes with typical B-type faces, and shortest in bush dogs with typical C-type faces. These results suggest that the facial color pattern of canid species is related to their gaze communication and that canids with A-type faces, especially gray wolves, use the gaze signal in conspecific communication.
Practical Use of Gemcitabine and Cisplatin Combination Therapy as First-Line Treatment for Japanese Patients with Advanced Biliary Tract Cancer  [PDF]
Hisato Kawakami, Isamu Okamoto, Wataru Okamoto, Masayuki Takeda, Shinya Ueda, Toshihiro Kudo, Shin-ichi Nishina, Yasuhito Fujisaka, Masaki Miyazaki, Junji Tsurutani, Takayasu Kurata, Kazuhiko Nakagawa
Journal of Cancer Therapy (JCT) , 2013, DOI: 10.4236/jct.2013.46121

Gemcitabine and cisplatin combination therapy (GC) is accepted as a standard treatment for advanced biliary tract cancer (BTC). However, little information is available regarding such treatment in the clinical practice setting in Japan. We retrospectively examined the clinical data of patients with unresectable or recurrent BTC who received GC as first-line treatment. The regimen consisted of cisplatin (25 mg/m2) and gemcitabine (1000 mg/m2) administered intravenously on days 1 and 8 of repeated 3-week cycles. Twenty patients were analyzed. A total of 148 cycles of GC was administered, with a median of 8 and a range of 1 to 18 cycles. Treatment delay and dose reduction were noted in 35 (24%) and 41 (28%) of the 148 cycles, respectively. The major adverse events of grade 3 or 4 included neutropenia (50%), leukopenia (45%), anemia (30%), and thrombocytopenia (15%). Nonhematologic toxicities included nausea (10%), appetite loss (10%), and fatigue (10%). Median progression-free and overall survival times were 6.9 and 12.3 months, respectively. Gallbladder cancer showed a significantly higher response rate than did other types of BTC (chi-squaretest, P = 0.002). GC was thus effective and well tolerated as first-line chemotherapy for Japanese patients with advanced BTC in the clinical practice setting.

Cardiac Arrest during Gamete Release in Chum Salmon Regulated by the Parasympathetic Nerve System
Yuya Makiguchi, Shinya Nagata, Takahito Kojima, Masaki Ichimura, Yoshifumi Konno, Hideki Murata, Hiroshi Ueda
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0005993
Abstract: Cardiac arrest caused by startling stimuli, such as visual and vibration stimuli, has been reported in some animals and could be considered as an extraordinary case of bradycardia and defined as reversible missed heart beats. Variability of the heart rate is established as a balance between an autonomic system, namely cholinergic vagus inhibition, and excitatory adrenergic stimulation of neural and hormonal action in teleost. However, the cardiac arrest and its regulating nervous mechanism remain poorly understood. We show, by using electrocardiogram (ECG) data loggers, that cardiac arrest occurs in chum salmon (Oncorhynchus keta) at the moment of gamete release for 7.39±1.61 s in females and for 5.20±0.97 s in males. The increase in heart rate during spawning behavior relative to the background rate during the resting period suggests that cardiac arrest is a characteristic physiological phenomenon of the extraordinarily high heart rate during spawning behavior. The ECG morphological analysis showed a peaked and tall T-wave adjacent to the cardiac arrest, indicating an increase in potassium permeability in cardiac muscle cells, which would function to retard the cardiac action potential. Pharmacological studies showed that the cardiac arrest was abolished by injection of atropine, a muscarinic receptor antagonist, revealing that the cardiac arrest is a reflex response of the parasympathetic nerve system, although injection of sotalol, a β-adrenergic antagonist, did not affect the cardiac arrest. We conclude that cardiac arrest during gamete release in spawning release in spawning chum salmon is a physiological reflex response controlled by the parasympathetic nervous system. This cardiac arrest represents a response to the gaping behavior that occurs at the moment of gamete release.
Secretome Analysis of the Pine Wood Nematode Bursaphelenchus xylophilus Reveals the Tangled Roots of Parasitism and Its Potential for Molecular Mimicry
Ryoji Shinya, Hironobu Morisaka, Taisei Kikuchi, Yuko Takeuchi, Mitsuyoshi Ueda, Kazuyoshi Futai
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067377
Abstract: Since it was first introduced into Asia from North America in the early 20th century, the pine wood nematode Bursaphelenchus xylophilus has caused the devastating forest disease called pine wilt. The emerging pathogen spread to parts of Europe and has since been found as the causal agent of pine wilt disease in Portugal and Spain. In 2011, the entire genome sequence of B. xylophilus was determined, and it allowed us to perform a more detailed analysis of B. xylophilus parasitism. Here, we identified 1,515 proteins secreted by B. xylophilus using a highly sensitive proteomics method combined with the available genomic sequence. The catalogue of secreted proteins contained proteins involved in nutrient uptake, migration, and evasion from host defenses. A comparative functional analysis of the secretome profiles among parasitic nematodes revealed a marked expansion of secreted peptidases and peptidase inhibitors in B. xylophilus via gene duplication and horizontal gene transfer from fungi and bacteria. Furthermore, we showed that B. xylophilus secreted the potential host mimicry proteins that closely resemble the host pine’s proteins. These proteins could have been acquired by host–parasite co-evolution and might mimic the host defense systems in susceptible pine trees during infection. This study contributes to an understanding of their unique parasitism and its tangled roots, and provides new perspectives on the evolution of plant parasitism among nematodes.
Genetic Characterization of Hepatitis C Virus in Long-Term RNA Replication Using Li23 Cell Culture Systems
Nobuyuki Kato, Hiroe Sejima, Youki Ueda, Kyoko Mori, Shinya Satoh, Hiromichi Dansako, Masanori Ikeda
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0091156
Abstract: Background The most distinguishing genetic feature of hepatitis C virus (HCV) is its remarkable diversity and variation. To understand this feature, we previously performed genetic analysis of HCV in the long-term culture of human hepatoma HuH-7-derived HCV RNA-replicating cell lines. On the other hand, we newly established HCV RNA-replicating cell lines using human hepatoma Li23 cells, which were distinct from HuH-7 cells. Methodology/Principal Findings Li23-derived HCV RNA-replicating cells were cultured for 4 years. We performed genetic analysis of HCVs recovered from these cells at 0, 2, and 4 years in culture. Most analysis was performed in two separate parts: one part covered from the 5′-terminus to NS2, which is mostly nonessential for RNA replication, and the other part covered from NS3 to NS5B, which is essential for RNA replication. Genetic mutations in both regions accumulated in a time-dependent manner, and the mutation rates in the 5′-terminus-NS2 and NS3-NS5B regions were 4.0–9.0×10?3 and 2.7–4.0×10?3 base substitutions/site/year, respectively. These results suggest that the variation in the NS3-NS5B regions is affected by the pressure of RNA replication. Several in-frame deletions (3–105 nucleotides) were detected in the structural regions of HCV RNAs obtained from 2-year or 4-year cultured cells. Phylogenetic tree analyses clearly showed that the genetic diversity of HCV was expanded in a time-dependent manner. The GC content of HCV RNA was significantly increased in a time-dependent manner, as previously observed in HuH-7-derived cell systems. This phenomenon was partially due to the alterations in codon usages for codon optimization in human cells. Furthermore, we demonstrated that these long-term cultured cells were useful as a source for the selection of HCV clones showing resistance to anti-HCV agents. Conclusions/Significance Long-term cultured HCV RNA-replicating cells are useful for the analysis of evolutionary dynamics and variations of HCV and for drug-resistance analysis.
Phylogeny and Phylogeography of Myrmica rubra Complex (Myrmicinae) in the Japanese Alps
Shouhei Ueda,Taito Nozawa,Tetsuya Matsuzuki,Ryo-ichi Seki,Shinya Shimamoto,Takao Itino
Psyche , 2012, DOI: 10.1155/2012/319097
Abstract: We investigated the genetic diversification of the mountain ant, Myrmica kotokui, in the Japanese Alps by using molecular phylogenetic analyses. Myrmica kotokui is widely distributed in Japan, and in the central Japanese Alps it is found only between elevations of approximately 1000 to 2000?m. We hypothesized that genetically distinct clades of this ant species might inhabit different mountain ranges in central Japan. To test this hypothesis, we reconstructed a molecular phylogeny using the DNA sequences of the mitochondrial cytochrome oxidase I gene and the nuclear long-wavelength rhodopsin gene of M. kotokui specimens collected from six mountain ranges in the Japanese Alps. The phylogeny showed four highly differentiated clades. However, the correspondence between the clades and morphological species was a little confusing. Two clades were composed only of M. kotokui specimens, whereas the other two clades were composed of multispecies, suggesting the possibility of multispecies composition of putative M. kotokui. The distribution pattern of these clades did not support our hypothesis of geographical differentiation, because two were distributed across all ranges, and a third was distributed in five of the six ranges. On the other hand, we found a pattern in the altitudinal distribution of the clades: one clade was distributed only at higher elevations, and the others were distributed at lower elevations. Thus, the ant clades do not show geographical segregation by mountain range, but they do show altitudinal differences. 1. Introduction Modern molecular phylogenetic techniques have revealed that some morphological species are composed of several genetically distinct cryptic species [1]. To evaluate the biodiversity of a taxonomic group, it is essential to identify cryptic species, and biogeographical studies that determine the distributions of cryptic species are of crucial importance in conservation biology. Although many cryptic species have been found in several ant genera by using molecular phylogenetic techniques [2–5], it is difficult to identify cryptic species by using traditional morphological classification techniques alone, because intraspecific morphological variation may be greater than the interspecific variation and because convergently evolved characters may not show any morphological variation among species [3, 5]. For instance, Schlick-Steiner et al. [4] used mitochondrial DNA (mtDNA) to reconstruct the phylogeny of a Tetramorium ant species complex. Although the species of this complex are difficult to distinguish morphologically,
Resistivity reduction of boron-doped multi-walled carbon nanotubes synthesized from a methanol solution containing a boric acid
Satoshi Ishii,Tohru Watanabe,Shinya Ueda,Shunsuke Tsuda,Takahide Yamaguchi,Yoshihiko Takano
Physics , 2008, DOI: 10.1063/1.2930677
Abstract: Boron-doped multi-walled carbon nanotubes (MWNTs) were synthesized using a methanol solution of boric acid as a source material. Accurate measurements of the electrical resistivity of an individual boron-doped MWNT was performed with a four-point contact, which was fabricated using an electron beam lithography technique. The doped boron provides conduction carriers, which reduces the resistivity of the MWNT.
The truncated disk from Suzaku data of GX 339-4 in the extreme very high state
Manami Tamura,Aya Kubota,Shinya Yamada,Chris Done,Mari Kolehmainen,Yoshihiro Ueda,Shunsuke Torii
Physics , 2012, DOI: 10.1088/0004-637X/753/1/65
Abstract: We report on the geometry of accretion disk and high energy coronae in the strong Comptonization state (the very high/steep power law/hard intermediate state) based on a Suzaku observation of the famous Galactic black hole GX 339-4. These data were taken just before the peak of the 2006-2007 outburst, and the average X-ray luminosity in the 0.7-200 keV band is estimated to be 2.9E38 erg/s for a distance of 8 kpc. We fit the spectrum with both simple (independent disk and corona) and sophisticated (energetically coupled disk and corona) models, but all fits imply that the underlying optically thick disk is truncated significantly before the innermost stable circular orbit around the black hole. We show this directly by a comparison with similarly broadband data from a disk dominated spectrum at almost the same luminosity observed by XMM-Newton and RXTE 3 days after the Suzaku observation. During the Suzaku observation, the QPO frequency changes from 4.3 Hz to 5.5 Hz, while the spectrum softens. The energetically coupled model gives a corresponding 5+/- 8 % decrease in derived inner radius of the disk. While this is not significant, it is consistent with the predicted change in QPO frequency from Lense-Thirring precession of the hot flow interior to the disk and/or a deformation mode of this flow, as a higher QPO frequency implies a smaller size scale for the corona. This is consistent with the truncated disk extending further inwards towards the black hole.
Chromosomal Studies of Masculinized Hybrids in Bitterlings (Teleostei: Cypriniformes: Acheilognathinae)  [PDF]
Takayoshi Ueda, Yukie Ueda
Natural Resources (NR) , 2016, DOI: 10.4236/nr.2016.76028
Abstract: The chromosome analysis of the masculinized hybrid between female Tanakia limbata and male T. signifer in bitterlings (Acheilognathinae) was done. It was presumed that they had intermediate karyotype between the parents, and formed sperms with heteroploidy resulting from the incomplete pairing of homologous chromosomes in meiosis. Due to the abundance of species and the ease of artificial fertilization, the study of the factor of the hybrid sterility in bitterlings would lead to the clarification of the mechanism about species differentiation and karyotype differentiation, and also to developing a new variety.
Chromosomal Studies of the Hybrid between Female Rhodeus ocellatus ocellatus and Male Rhodeus atremius fangi in Bitterlings (Teleostei: Cypriniformes: Acheilognathinae)  [PDF]
Takayoshi Ueda, Yukie Ueda
Natural Resources (NR) , 2018, DOI: 10.4236/nr.2018.91002
The chromosome analysis of the masculinized hybrid between female Rhodeus ocellatus ocellatus and male R. atremius fangi in bitterlings (Acheilognathinae) was done. It was presumed that they had intermediate karyotype between the parents, and formed sperms with heteroploidy resulting from the incomplete pairing of homologous chromosomes in meiosis. Due to the abundance of species and the ease of artificial fertilization, the study of the factor of the hybrid sterility in bitterlings would lead to the clarification of the mechanism about species differentiation and karyotype differentiation, and also develop a new variety. And also, it would also be important to make the hybrid various natures clear in environmental preservation.
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