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1.
Makoto Sakurai Susumu Nakakoji Hisaya Manabe Shin-ichi Dewa Akihiko Shinomiya Tomoki Sunobe 《Ichthyological Research》2009,56(1):82-86
Bi-directional sex change in the deep-water gobiid fish Trimma yanagitai was examined. The gonads of all individuals consisted of ovarian and testicular elements, and an accessory gonadal structure.
In no gonads were both testicular and ovarian parts simultaneously active. Bi-directional sex changes occurred during the
rearing experiments in aquaria under conditions of which there was co-existence of two males or plural females. The sex of
individuals could be determined by their relative body size or social dominance: the largest individuals acting as male and
the remainder as female. 相似文献
2.
Eri Sakurai Takashi Kurihara Kasumi Kouchi Hironao Saegusa Shuqin Zong Tsutomu Tanabe 《Molecular pain》2009,5(1):1-14
Glycine receptors (GlyRs) play important roles in regulating hippocampal neural network activity and spinal nociception. Here we show that, in cultured rat hippocampal (HIP) and spinal dorsal horn (SDH) neurons, 17-β-estradiol (E2) rapidly and reversibly reduced the peak amplitude of whole-cell glycine-activated currents (I Gly). In outside-out membrane patches from HIP neurons devoid of nuclei, E2 similarly inhibited I Gly, suggesting a non-genomic characteristic. Moreover, the E2 effect on I Gly persisted in the presence of the calcium chelator BAPTA, the protein kinase inhibitor staurosporine, the classical ER (i.e. ERα and ERβ) antagonist tamoxifen, or the G-protein modulators, favoring a direct action of E2 on GlyRs. In HEK293 cells expressing various combinations of GlyR subunits, E2 only affected the I Gly in cells expressing α2, α2β or α3β subunits, suggesting that either α2-containing or α3β-GlyRs mediate the E2 effect observed in neurons. Furthermore, E2 inhibited the GlyR-mediated tonic current in pyramidal neurons of HIP CA1 region, where abundant GlyR α2 subunit is expressed. We suggest that the neuronal GlyR is a novel molecular target of E2 which directly inhibits the function of GlyRs in the HIP and SDH regions. This finding may shed new light on premenstrual dysphoric disorder and the gender differences in pain sensation at the CNS level. 相似文献
3.
Morikawa Hiromichi; Hayashi Yasuyuki; Hirabayashi Yasuzi; Asada Masanori; Yamada Yasuyuki 《Plant & cell physiology》1988,29(1):189-193
Protoplasts isolated from cultured cells of Coptis japonicaand Euphorbia millii were electrically fused using platinummicroelectrodes. The process involved two stages, cellular andvacuolar fusion, which are characterized respectively by transientwrinkling of the membrane and the formation of a dark-red precipitate. (Received June 12, 1987; Accepted October 13, 1987) 相似文献
4.
5.
Itoh T Terazawa R Kojima K Nakane K Deguchi T Ando M Tsukamasa Y Ito M Nozawa Y 《Free radical research》2011,45(9):1033-1039
This study aimed to examine the roles of reactive oxygen species (ROS) in cisplatin treatment of human prostate cancer cells; hormone-sensitive LNCaP and hormone-refractory PC3 and DU145 cells. Intracellular levels of ROS and H(2)O(2) were measured and visualized using specific fluorescent probes. NADPH oxidase (NOX) activity was detected by lucigenin chemiluminescence assay. Expression levels of NOX isoforms were determined by semi-quantitative RT-PCR. Cisplatin treatment increased the intracellular levels of ROS and H(2)O(2) in three prostate cancer cell lines. The increase was transient and robust in hormone-sensitive LNCaP cells compared with hormone-refractory PC3 and DU145 cells. Consistent with these findings, the NOX activity induced by cisplatin was higher in LNCaP cells than in PC3 and DU145 cells. Expression pattern of NOX isoforms varied among three cell lines and the NOX activity was independent of NOX expression. Taken together, we have shown that cisplatin induces production of ROS and H(2)O(2) via NOX activation in human prostate cancer cell lines, which is most prominent in hormone-sensitive LNCaP cells. 相似文献
6.
Kevin Montagne Raphael Plasson Yasuyuki Sakai Teruo Fujii Yannick Rondelez 《Molecular systems biology》2011,7(1)
Living organisms perform and control complex behaviours by using webs of chemical reactions organized in precise networks. This powerful system concept, which is at the very core of biology, has recently become a new foundation for bioengineering. Remarkably, however, it is still extremely difficult to rationally create such network architectures in artificial, non‐living and well‐controlled settings. We introduce here a method for such a purpose, on the basis of standard DNA biochemistry. This approach is demonstrated by assembling de novo an efficient chemical oscillator: we encode the wiring of the corresponding network in the sequence of small DNA templates and obtain the predicted dynamics. Our results show that the rational cascading of standard elements opens the possibility to implement complex behaviours in vitro. Because of the simple and well‐controlled environment, the corresponding chemical network is easily amenable to quantitative mathematical analysis. These synthetic systems may thus accelerate our understanding of the underlying principles of biological dynamic modules. 相似文献
7.
Schizophyllan (SPG), a beta-1,3-glucan polysaccharide which is known to form macromolecular complexes with certain polynucleotides, was modified by a reductive amination method with alpha-amino acids (Arg, Lys, and Ser). The thermal stability of the complexes as estimated by T(m) was enhanced in SPG-Arg and SPG-Lys conjugates which have pI values higher than the pH of the medium (8.0). The T(m) shift increased with the increase in the percentage of alpha-amino acid introduced and the highest T(m) values attained were 64 degrees C for SPG-Arg conjugate and 62 degrees C for SPG-Lys conjugate, which are higher by 13 and 11 degrees C, respectively, than those of the unmodified SPG+poly(C) complex. In the SPG-Ser conjugate with a pI lower than the medium pH (8.0), the T(m) values decreased with an increase in the percentage of Ser. Formation of the macromolecular complex was no longer detected above 13.2% Ser. The findings indicate that the T(m) values are easily controllable by the type and percentage of the introduced alpha-amino acids. We believe, therefore, that the present conjugates, consisting of naturally originated SPG and alpha-amino acids, provide an important lead for developing nontoxic artificial vectors and to control the affinity with polynucleotides in response to medium pH and temperature. 相似文献
8.
The type I Cu site in the Cys457Ser mutant of Myrothecium verrucaria bilirubin oxidase was vacant, but the trinuclear center composed of a type II Cu and a pair of type III Cu's was fully occupied by three Cu ions. Cys457Ser could react with dioxygen, affording reaction intermediate I with absorption maxima at 340, 470, and 675 nm. This intermediate corresponds to that obtained from laccase, whose type I Cu is cupric and type II and III Cu's are cuprous [Zoppellaro, G., Sakurai, T., and Huang, H. (2001) J. Biochem. 129, 949-953] or whose type I Cu is substituted with Hg [Palmer, A. E., Lee, S. K., and Solomon, E. I. (2001) J. Am. Chem. Soc. 123, 6591-6599]. Another type I Cu mutant, Met467Gln, with modified spectroscopic properties and redox potential, afforded reaction intermediate II with absorption maxima at 355 and 450 nm. This intermediate corresponds to that obtained during the reaction of laccase [Sundaram, U. M., Zhang, H. H., Hedman, B., Hodgson, K. O., and Solomon, E. I. (1997) J. Am. Chem. Soc. 119, 12525-12540; Huang, H., Zoppellaro, G., and Sakurai, T. (1999) J. Biol. Chem. 274, 32718-32724]. According to a three-dimensional model of bilirubin oxidase, Asp105 is positioned near the trinuclear center. Asp105Glu and Asp105Ala exhibited 46 and 7.5% bilirubin oxidase activity compared to the wild-type enzyme, respectively, indicating that Asp105 conserved in all multi-copper oxidases donates a proton to reaction intermediates I and II. In addition, this amino acid might be involved in the formation of the trinuclear center and in the binding of dioxygen based on the difficulties in incorporating four Cu ions in Asp105Ala and Asp105Asn and their reactions with dioxygen. 相似文献
9.
alphaB-Crystallin, a member of the small heat shock protein (sHSP) family, is expressed in various tissues including lens, heart, and skeletal muscle. Previously we identified the gene of HSPB2, another member of the sHSP family, located 1-kb upstream of the alphaB-crystallin gene in a head-to-head manner. In the present study, we found a highly conserved region of 220 bp approximately 2.4-kb upstream of the alphaB-crystallin gene and examined its role in expression of the alphaB-crystallin gene. Transgenic mice containing 3 kb of the upstream sequence of the alphaB-crystallin gene showed lacZ reporter gene expression in the lens as well as the myotome and heart on embryonic day 12.5. Deletion analysis revealed that the -2656/-2267 region including the conserved region with four putative Sox binding elements (E1-E4) exhibits lens enhancer activity toward the alphaB-crystallin promoter. Gel shift assays showed that the Sox1 and Sox2 proteins preferentially bound to E2 and E4. Moreover, disruption of E2 and E4 abolished the reporter gene expression in the lens. These results indicate that the newly identified enhancer with Sox elements activates the alphaB-crystallin promoter in the lens, although they are separated by the entire HSPB2 gene. 相似文献
10.
Kuroki H Nakagawa Y Mori K Ohba M Suzuki T Mizuno Y Ando K Takenaka M Ikeuchi K Nakamura T 《Arthritis research & therapy》2004,6(6):R492-R504
We investigated quantitative changes over time in ultrasound signal intensity (an index of stiffness), signal duration (an index of surface irregularity), and interval between signals (an index of thickness) of plug cartilage in an animal model of autologous osteochondral grafting. A full-thickness osteochondral plug was surgically removed and replaced in male Japanese white rabbits (n = 22). Specimens obtained at day 0 and weeks 2, 4, 8, 12 and 24 postoperatively were assessed using an ultrasound system and by macroscopic and histological evaluation (modified Mankin's score). Histology revealed that the plug sank until 2 weeks postoperatively, and that newly formed cartilage-like tissue covered the plug, but at 24 weeks the tissue detached. The plug itself survived well throughout the period of observation. Although the signal intensity at the plug site was same as that in the sham operated contralateral knee at day 0, from 2 to 24 weeks postoperatively it was less than that in the sham knee. At 8 weeks, this difference was significant (P < 0.05). Modified Mankin's score revealed early degenerative changes at the site, but macroscopic examination did not. Signal intensity correlated significantly with score (both at day 0 and at the five postoperative time points [P < 0.05, r = -0.91] and as a whole [P < 0.05, r = -0.36]). Signal intensity also significantly correlated with the individual subscores for 'cartilage structure' (P < 0.05, r = -0.32) and 'cartilage cells' (P < 0.05, r = -0.30) from the modified Mankin's score, but not significantly with subscores for 'staining' and 'tidemark'. Signal duration correlated significantly with total score (as a whole [P < 0.05, r = 0.34]), but not significantly with the score for cartilage structure (P = 0.0557, r = 0.29). The interval between signals reflected well the actual thickness of the plug site. The significant relationships between ultrasound signal intensity and scores suggest that early degenerative changes in plug cartilage and cartilage-like tissue, especially in the superficial layer, are detectable by high-frequency ultrasound assessment. 相似文献