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991.
Amoeboid movement is believed to involve a pressure gradient along the cell length, with contractions in the posterior region driving cytoplasmic streaming forward. However, a parallel mechanism has yet to be demonstrated in migrating adhesive cells. To probe the distribution of intracellular forces, we microinjected high molecular weight linear polyacrylamide (PAA) as a passive force sensor into migrating NIH3T3 fibroblasts. Injected PAA appeared as amorphous aggregates that underwent shape change and directional movement in response to differential forces exerted by the surrounding environment. PAA injected into the posterior region moved toward the front, whereas PAA in the anterior region never moved to the posterior region. This preferential forward movement was observed only in migrating cells with a defined polarity. Disruption of myosin II activity by blebbistatin inhibited the forward translocation of PAA while cell migration persisted in a disorganized fashion. These results suggest a myosin II-dependent force gradient in migrating cells, possibly as a result of differential cortical contractions between the anterior and posterior regions. This gradient may be responsible for the forward transport of cellular components and for maintaining the directionality during cell migration. 相似文献
992.
Sekiguchi M Iwasaki T Kitano M Kuno H Hashimoto N Kawahito Y Azuma M Hla T Sano H 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(3):1921-1928
Primary Sj?gren's syndrome (SS) is an autoimmune disease characterized by inflammatory mononuclear cell infiltration and destruction of epithelial cells of lacrimal and salivary glands. Sphingosine 1-phosphate (S1P) and signaling through its receptor S1P(1) have been implicated in many critical cellular events including inflammation, cancer, and angiogenesis. This study was undertaken to examine the role of S1P(1) signaling in the pathogenesis of primary SS. S1P(1) and sphingosine kinase 1, which converts sphingosine to S1P, were detected in the cytoplasm of inflammatory mononuclear cells, vascular endothelial cells, and epithelial cells in all labial salivary glands by immunohistochemistry. The expression of S1P(1) in inflammatory mononuclear cells was enhanced in advanced stages of primary SS. S1P enhanced proliferation and IFN-gamma production by CD4(+) T cells. The enhancing effect of S1P on IFN-gamma production by CD4(+) T cells was stronger in patients with primary SS than in healthy controls. S1P also enhanced Fas expression and Fas-mediated caspase-3 induction in salivary gland epithelial cells. IL-6 expression was detected in the cytoplasm of inflammatory mononuclear cells and ductal epithelial cells and was enhanced in advanced stages of primary SS. Furthermore, both IFN-gamma and S1P augmented IL-6 secretion by salivary gland epithelial cells. These effects of S1P were inhibited by pretreatment of pertussis toxin. Our data reveal that S1P(1) signaling may modulate the autoimmune phenotype of primary SS by the action of immune as well as epithelial cells. 相似文献
993.
Lithocholic acid derivatives act as selective vitamin D receptor modulators without inducing hypercalcemia 总被引:3,自引:0,他引:3
Ishizawa M Matsunawa M Adachi R Uno S Ikeda K Masuno H Shimizu M Iwasaki K Yamada S Makishima M 《Journal of lipid research》2008,49(4):763-772
1alpha,25-Dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], a vitamin D receptor (VDR) ligand, regulates calcium homeostasis and also exhibits noncalcemic actions on immunity and cell differentiation. In addition to disorders of bone and calcium metabolism, VDR ligands are potential therapeutic agents in the treatment of immune disorders, microbial infections, and malignancies. Hypercalcemia, the major adverse effect of vitamin D(3) derivatives, limits their clinical application. The secondary bile acid lithocholic acid (LCA) is an additional physiological ligand for VDR, and its synthetic derivative, LCA acetate, is a potent VDR agonist. In this study, we found that an additional derivative, LCA propionate, is a more selective VDR activator than LCA acetate. LCA acetate and LCA propionate induced the expression of the calcium channel transient receptor potential vanilloid type 6 (TRPV6) as effectively as that of 1alpha,25-dihydroxyvitamin D(3) 24-hydroxylase (CYP24A1), whereas 1,25(OH)(2)D(3) was more effective on TRPV6 than on CYP24A1 in intestinal cells. In vivo experiments showed that LCA acetate and LCA propionate effectively induced tissue VDR activation without causing hypercalcemia. These bile acid derivatives have the ability to function as selective VDR modulators. 相似文献
994.
995.
Makoto Shiozaki Hiroto Imai Katsuya Maeda Tomoya Miura Katsutaka Yasue Akira Suma Masahiro Yokota Yosuke Ogoshi Julia Haas Andrew M. Fryer Ellen R. Laird Nicole M. Littmann Steven W. Andrews John A. Josey Takayuki Mimura Yuichi Shinozaki Hiromi Yoshiuchi Takashi Inaba 《Bioorganic & medicinal chemistry letters》2009,19(21):6213-6217
A series of 1-sulfonylaminocyclopropanecarboxylates was synthesized as ADAMTS-5 (Aggrecanase-2) inhibitors. After an intensive investigation of the central cyclopropane core including its absolute stereochemistry and substituents, we found compound 22 with an Agg-2 IC50 = 7.4 nM, the most potent ADAMTS-5 inhibitor reported so far. 相似文献
996.
Hybrid density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been carried out for ozone-water clusters O3(H2O)n (n = 1-4) in order to obtain hydration effects on the absorption spectrum of ozone. The first water molecule in n = 1 is bound to the ozone molecule by an oxygen orientation form in which the oxygen atom of H2O orients the central oxygen atom of O3. In n = 2, the water dimer is bound to O3 and then the cyclic structure is formed as the most stable structure. For n = 3 (or n = 4), the cyclic water trimer (or tetramer) is bound by a hydrogen bond to the ozone molecule. The TD-DFT calculations of O3(H2O)n (n = 0-4) show that the first and second excitation energies of O3 are blue-shifted by the interaction with the water clusters. The magnitude of the spectral shift is largest in n = 2, and the shifts of the excitation energies are +0.07 eV for S1 and +0.13 eV for S2 states. In addition to the spectral shifts (S1 and S2 states), it is suggested that a charge-transfer band is appeared as a low-lying excited state above the S1 and S2 states. The origin of the spectrum shifts was discussed on the basis of theoretical results. 相似文献
997.
998.
Yuichi Hayashi Yasushi Iwasaki Nobuaki Yoshikura Takahiko Asano Maya Mimuro Akio Kimura 《朊病毒》2017,11(4):284-292
We report an autopsy-verified case of steroid-responsive encephalopathy with convulsion and a false-positive result from the real-time quaking-induced conversion (RT-QUIC) assay. A 61-year-old Japanese man presented with acute onset of consciousness disturbance, and convulsions, but without a past medical or family history of progressive dementia, epilepsy, or prion disease. Brain diffusion and fluid-attenuated inverted recovery MR images revealed edematous cortical hyper-intensity, which diminished after the acute phase. Steroid pulse therapy was partially effective, although he continued to have dementia with myoclonus and psychiatric symptoms, despite resolution of the consciousness disturbance. Cerebrospinal fluid (CSF) analysis revealed a normal cell count, with significantly elevated levels of 14–3–3 protein and total tau protein. In addition, prion protein in the CSF was slowly amplified by the RT-QUIC assay. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. The patient died of sudden cardiac arrest at 3 months after the onset of symptoms.
The positive result from the RT-QUIC assay led us to suspect involvement of prion disease, although a postmortem assessment revealed that he had pathological changes after convulsion, and no prion disease. This case indicates that convulsion may cause false-positive RT-QUIC results, and that a postmortem evaluation remains the gold standard for diagnosing similar cases. 相似文献
999.
Yasushi Iwasaki Keiko Mori Masumi Ito Yoshinari Kawai Ken-ichiro Hoshino Yuko Kawabata 《朊病毒》2017,11(3):186-194
Patients with prion diseases can live for long periods of time in a state of akinetic mutism given appropriate management of their symptoms. To study symptom support in these cases, we performed gastrostomies on 3 patients with V180I genetic Creutzfeldt-Jakob disease (CJD) who had become akinetic and mute, and compared them to 14 other similar patients being fed by tube. In the 3 gastrostomy cases, there were no direct complications due to the gastrostomy or tube feeding, nor were there episodes of discontinuation of tube feeding or initiation of continuous drip infusion due to severe complications. Antibiotics were administered for mild infections, a complication of CJD, with 0.2% and 8.8% of the total time after gastrostomy being used for intravenous or transluminal administration, respectively. We compared the present patient series with that of our previous report statistically, and found that patients undergoing gastrostomy required significantly fewer discontinuations of tube feeding than those who did not. No significant difference in antibiotic administration was found between groups, however. It is our conclusion that gastrostomy should be allowed for symptom support in akinetic patients with prion disease, but adequate informed consent must be provided to the patient's family. 相似文献
1000.
Md. Shafiqul Islam Arihiro Iwasaki Kiyotake Suenaga Hisashi Kato-Noguchi 《Journal of Plant Biology》2017,60(1):75-81
Organic agriculture emphasized using of biologically originated herbicides and phytotoxic substances are being considered as a replacement to chemical herbicides. Marsilea crenata is an aquatic perennial fern distributed in the South-East Asian countries and is well known for various biological properties. However, to date, there has been no report that addresses the phytotoxicity of Marsilea crenata. Therefore, we explored phytotoxic properties and phytotoxic substances from Marsilea crenata. An aqueous methanol extracts of Marsilea crenata showed inhibition on the seedling growth of cress, lettuce, alfalfa, barnyard grass, Italian ryegrass, and foxtail fescue. Inhibition increased with increasing extract concentration. The extract was purified by several chromatographic steps and two phytotoxic substances were isolated and identified by spectroscopic analysis as loliolide and isololiolide. At the concentration of 30 μM, loliolide and isololiolide inhibited seedling growth of cress and barnyard grass by 41.3 to 51.1%, and 58.15 to 87.5% of control seedlings, respectively. The concentrations required for 50% inhibition of cress and barnyard grass seedlings ranged from 32.1 to 128.5 μM for loliolide, 37.0 to 176.2 μM for isololiolide. These results suggest these compounds may be responsible for phytotoxic effects of Marsilea crenata extract and could be an important part of organic agriculture. 相似文献