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101.
Emotional stress evoked by immobilization of the rat induces c-fos mRNA or other immediate early genes. This response is mediated by activation of alpha- and beta-adrenoceptors, through mechanisms that have not yet been elucidated. Here we show that immobilization stress activates p44/p42 Mitogen-Activated Protein kinase (p44/p42 MAP kinase, Erk1/Erk2). Pretreatment with the beta1-blocker, metoprolol, did not inhibit the activation of stress-induced MAP kinase, while blockage of the alpha1-adrenoceptor by pretreatment with alpha1-blocker, prazosin or the alpha/beta-blocker, amosulalol, attenuated the activation. Application of the alpha1-agonist, phenylephrine, but not the beta-agonist, isoproterenol, to the perfused rat heart elicited MAP activation. Thus, emotional stress activates the alpha1-adrenoceptor-mediated MAP kinase pathway, whereas the pathway of the response mediated by the beta-adrenoceptor remains unknown. 相似文献
102.
Teiji Takechi Katsuhisa Koizumi Atsushi Azuma Masakazu Fukushima Katsutoshi Kobayashi Shinya Oda Katsuhiko Yanaga Leon Mullenders Peter Karran Masatsugu Ueda Yoshito Terai Minoru Ueki Masaru Sakamoto Aako Kondo Kiyohiko Miyake Yauko Koyamatsu Tsukasa Akiya Makoto Nakano Hiroshi Iwabuchi Tetsuya Muroya Yoshio Tenjin Kazunori Ochiai Tadao Tanaka Kyosuke Ymada Kazu Ueda Akihiko Misawa Aikou Okamoto Eizo Kimura Makoto Yasuda 《Human cell》2004,17(2):16-21
103.
Polymer-bound nitridomolybdenum(VI) complexes, MoNCl3(polystyrene-bound bipyridyl) (I), MoNCl2(bpy)(polystyrene-bound benzylthiolato) (II), and MoNCl (S-t-Bu)(bpy)(polystyrene-bound benzylthiolato) (III), were synthesized by the reaction of MoNCl3(CH3CN)x or MoNCl3(bpy) with polystyrene-bound bipyridyl or benzylthiol. The polymer-bound nitridomolybdenum complexes were characterized by photo-acoustic and resonance Raman spectra. Hydrolysis or hydrolytic reduction of the nitridomolybdenum(VI) complexes resulted in the formation of ammonia in the following order of yield: III & II & I. Coordination of the polymer thiolato ligands is thus important in enhancing reductive cleavage of the nitridomolybdenum bond. 相似文献
104.
Tomohiro Ueda Tomohisa Takagi Kazuhiro Katada Takaya Iida Katsura Mizushima Osamu Dohi Tetsuya Okayama Naohisa Yoshida Kazuhiro Kamada Kazuhiko Uchiyama Osamu Handa Takeshi Ishikawa Hideyuki Konishi Yuji Naito Yukio Nagasaki Yoshito Itoh 《Biochemical and biophysical research communications》2018,495(2):2044-2049
Background
Intestinal ischemia-reperfusion (I-R) injury is a serious abdominal condition leading to multiple organ failure with high mortality. However, no reliable treatment is available. A redox nanoparticle (RNPO) was recently developed, and its efficacy for several intestinal inflammatory conditions has been reported. To this end, the aim of this study was to investigate the therapeutic effects of RNPO on intestinal I-R injury in mice.Methods
Ischemia was induced in the small intestine of C57BL/6 mice by occluding the superior mesenteric artery for 45 min under anesthesia followed by reperfusion for 4 h. Mice were orally administered the vehicle or RNPO 1 h before ischemia. Inflammatory markers such as histological findings, thiobarbituric acid (TBA)-reactive substances as an index of lipid peroxidation, myeloperoxidase (MPO) activity as an index of neutrophil infiltration, and expression of pro-inflammatory cytokine mRNA in the intestinal mucosa were assessed.Results
Induction of I-R caused a significant increase in inflammatory markers (histological scores, TBA-reactive substances, MPO activity, and expression of keratinocyte chemoattractant mRNA). These changes were significantly attenuated in RNPO-treated mice as compared to vehicle-treated mice.Conclusion
Orally administered RNPO attenuated intestinal I-R injury in mice in association with reductions in neutrophil infiltration and lipid peroxidation, suggesting the possibly potential of RNPO as a therapeutic agent for intestinal I-R injury. 相似文献105.
Hearing vulnerability after noise exposure in a mouse model of reactive oxygen species overproduction 下载免费PDF全文
Shigefumi Morioka Hirofumi Sakaguchi Taro Yamaguchi Yuzuru Ninoyu Hiroaki Mohri Takashi Nakamura Yasuo Hisa Kiyokazu Ogita Naoaki Saito Takehiko Ueyama 《Journal of neurochemistry》2018,146(4):459-473
106.
Emi Takeda Kohei Kunimoto Yoshito Kawai Misumi Kataoka Kazuhiko Ishikawa Takashi Nakamura 《Extremophiles : life under extreme conditions》2016,20(5):733-745
O-Phosphoserine sulfhydrylase (OPSS) synthesizes cysteine from O-phospho-l-serine (OPS) and sulfide. We have determined the three-dimensional structures of OPSS from hyperthermophilic archaeon Aeropyrum pernix K1 (ApOPSS) in complex with aminoacrylate intermediate (AA) formed from pyridoxal 5′-phosphate with OPS or in complex with cysteine and compared them with that of ApOPSS. We found an orientational change of F225 at the active-site entrance and constructed an F225A mutant to examine its activities and AA stability and clarify the role of F225 in ApOPSS. The OPS and O-acetyl-l-serine (OAS) sulfhydrylase activities of the F225A mutant decreased by 4.2- and 15-fold compared to those of the wild-type (wt) ApOPSS, respectively. The ability of OPS and OAS to form AA also decreased by 12- and 27-fold, respectively. AA was less stable in the F225A mutant than in the wt ApOPSS. Simulated docking showed that leaving groups, such as phosphate and acetate, were oriented to the inside of the active site in the F225A mutant, whereas they were oriented to the entrance in the wt ApOPSS. These results suggest that F225 in ApOPSS plays important roles in maintaining the hydrophobic environment of AA from solvent water and in controlling the orientation of leaving groups. 相似文献
107.
Youhei Takagi Kouhei Matsui Haruaki Nobori Haruka Maeda Akihiko Sato Takeshi Kurosu Yasuko Orba Hirofumi Sawa Kazunari Hattori Kenichi Higashino Yoshito Numata Yutaka Yoshida 《Bioorganic & medicinal chemistry letters》2017,27(15):3586-3590
NS2B-NS3 protease is an essential enzyme for the replication of dengue virus (DENV), which continues to be a serious threat to worldwide public health. We designed and synthesized a series of cyclic peptides mimicking the substrates of this enzyme, and assayed their activity against the DENV-2 NS2B-NS3 protease. The introduction of aromatic residues at the appropriate positions and conformational restriction generated the most promising cyclic peptide with an IC50 of 0.95 μM against NS2B-NS3 protease. Cyclic peptides with proper positioning of additional arginines and aromatic residues exhibited antiviral activity against DENV. Furthermore, replacing the C-terminal amide bond of the polybasic amino acid sequence with an amino methylene moiety stabilized the cyclic peptides against hydrolysis by NS2B-NS3 protease, while maintaining their enzyme inhibitory activity and antiviral activity. 相似文献
108.
Yuki Ueyama 《Journal of computational neuroscience》2017,43(1):93-106
Primary motor cortex (M1) neurons are tuned in response to several parameters related to motor control, and it was recently reported that M1 is important in feedback control. However, it remains unclear how M1 neurons encode information to control the musculoskeletal system. In this study, we examined the underlying computational mechanisms of M1 based on optimal feedback control (OFC) theory, which is a plausible hypothesis for neuromotor control. We modelled an isometric torque production task that required joint torque to be regulated and maintained at desired levels in a musculoskeletal system physically constrained by muscles, which act by pulling rather than pushing. Then, a feedback controller was computed using an optimisation approach under the constraint. In the presence of neuromotor noise, known as signal-dependent noise, the sensory feedback gain is tuned to an extrinsic motor output, such as the hand force, like a population response of M1 neurons. Moreover, a distribution of the preferred directions (PDs) of M1 neurons can be predicted via feedback gain. Therefore, we suggest that neural activity in M1 is optimised for the musculoskeletal system. Furthermore, if the feedback controller is represented in M1, OFC can describe multiple representations of M1, including not only the distribution of PDs but also the response of the neuronal population. 相似文献
109.
Kotaro Ise Yoshito Sasaki Yuki Amano Teruki Iwatsuki Isao Nanjo Takahiro Asano 《Geomicrobiology journal》2017,34(6):489-499
We investigated the change in bacterial community structure after drilling boreholes, 09-V250-M02 and 09-V250-M03, in the 250-m deep research gallery of the Horonobe Underground Research Laboratory. In the 09-V250-M02 borehole, ?-Proteobacteria were predominantly detected in the clone library analyses of the groundwater samples conducted immediately after drilling. All the ?-Proteobacteria clones were closely related to Arcobacter spp., which are known to be sulfide-oxidizing chemoautotrophic bacteria. After 4 years, the microbial structure drastically changed, and most detected operational taxonomic units were uncultured species such as candidate division OP9 and Chloroflexi relatives, which are frequently detected in deep sea sediments. The results indicated that the microbial community structure was drastically affected by borehole drilling and was concomitant with oxidation perturbation. However, these disturbed microbial communities changed within a few years to a microbial community composed of uncultivated species such as OP9 and Chloroflexi. 相似文献
110.
Intra‐trophic isotopic discrimination of 15N/14N for amino acids in autotrophs: Implications for nitrogen dynamics in ecological studies 下载免费PDF全文
Yuko Takizawa Prarthana S. Dharampal Shawn A. Steffan Yoshinori Takano Naohiko Ohkouchi Yoshito Chikaraishi 《Ecology and evolution》2017,7(9):2916-2924
The differential discrimination of nitrogen isotopes (15N/14N) within amino acids in consumers and their diets has been routinely used to estimate organismal tropic position (TP). Analogous isotopic discrimination can occur within plants, particularly in organs lacking chloroplasts. Such discrimination likely arises from the catabolic deamination of amino acids, resulting in a numerical elevation of estimated TP, within newly synthesized biomass. To investigate this phenomenon, we examined the 15N/14N of amino acids (δ15NAA) in spring leaves and flowers from eight deciduous and two annual plants. These plants were classified on the basis of their time of bloom, plants that bloomed when their leaves were absent (Type I) versus plants that bloomed while leaves were already present (Type II). Based on the δ15NAA values from leaves, both plant types occupied comparable and ecologically realistic mean TPs (=1.0 ± 0.1, mean ± 1σ). However, the estimated TPs of flowers varied significantly (Type I: 2.2 ± 0.2; Type II: 1.0 ± 0.1). We hypothesize that these results can be interpreted by the following sequence of events: (1) Type I floral biomass is synthesized in absence of active photosynthesis; (2) the catabolic deamination of amino acids in particular, leaves behind 15N in the residual pool of amino acids; and (3) the incorporation of these 15N‐enriched amino acids within the biomass of Type I flowers results in the numerical elevation of the TPs. In contrast, the actively photosynthesizing Type II leaves energetically sustain the synthesis of Type II flower biomass, precluding any reliance on catabolic deamination of amino acids. Amino acids within Type II flowers are therefore isotopically comparable to the Type II leaves. These findings demonstrate the idiosyncratic nature of the δ15NAA values within autotrophic organs and have implications for interpreting trophic hierarchies using primary producers and their consumers. 相似文献