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981.
The Sandhill Rustic moth Luperina nickerlii leechi is an isolate restricted to the beach of Loe Bar in Cornwall UK; it is a UK Priority taxon because of its unique status and small, declining population. The larval foodplant is Sand Couch-grass Elytrigia juncea; the larvae feed at first inside the stems and then on the rhizomes underground. The distribution of the moth and E. juncea were investigated in this study in relation to substrate conditions and other plants. E. juncea has an above-ground clumped distribution; near the sea the plants are linked by rhizomes, but away from the sea the apparent clumping is a probable historic record of previous connectivity where the rhizomes have disappeared. The adult moths were found to be associated with more vigorous E. juncea plants growing in sparsely vegetated, more disturbed ground near the sea, especially those plants with large rhizome systems along which later instar larvae can travel between plants. Emerging moths were associated with areas of extensive E. juncea surrounded by bare ground, where there was a substantial variation of shingle particles between 125?μm and 8?mm. The absence of vegetation and associated roots apart from E. juncea, and a coarse particle mix, may allow larvae to move through the shingle and the moths to push their way upwards from their subterranean pupae. We conclude that management should aim to create areas of bare ground with extensive patches of E. juncea growing in coarser shingle, with extensive underground connectivity and few other plants. 相似文献
982.
Spectrin repeats are three-helix bundle structures which occur in a large number of diverse proteins, either as single copies or in tandem arrangements of multiple repeats. They can serve structural purposes, by coordination of cytoskeletal interactions with high spatial precision, as well as a 'switchboard' for interactions with multiple proteins with a more regulatory role. We describe the structure of the alpha-actinin spectrin repeats as a prototypical example, their assembly in a defined antiparallel dimer, and the interactions of spectrin repeats with multiple other proteins. The alpha-actinin rod domain shares several features common to other spectrin repeats. (1) The rod domain forms a rigid connection between two actin-binding domains positioned at the two ends of the alpha-actinin dimer. The exact distance and rigidity are important, for example, for organizing the muscle Z-line and maintaining its architecture during muscle contraction. (2) The spectrin repeats of alpha-actinin have evolved to make tight antiparallel homodimer contacts. (3) The spectrin repeats are important interaction sites for multiple structural and signalling proteins. The interactions of spectrin repeats are, however, diverse and defy any simple classification of their preferred interaction sites, which is possible for other domains (e.g. src-homology domains 3 or 2). Nevertheless, the binding properties of the repeats perform important roles in the biology of the proteins where they are found, and lead to the assembly of complex, multiprotein structures involved both in cytoskeletal architecture as well as in forming large signal transduction complexes. 相似文献
983.
984.
Matthew J. Billard David J. Fitzhugh Joel S. Parker Jaime M. Brozowski Marcus W. McGinnis Roman G. Timoshchenko D. Stephen Serafin Ruth Lininger Nancy Klauber-Demore Gary Sahagian Young K. Truong Maria F. Sassano Jonathan S. Serody Teresa K. Tarrant 《PloS one》2016,11(4)
Triple negative breast cancer (TNBC) is a heterogeneous disease that has a poor prognosis and limited treatment options. Chemokine receptor interactions are important modulators of breast cancer metastasis; however, it is now recognized that quantitative surface expression of one important chemokine receptor, CXCR4, may not directly correlate with metastasis and that its functional activity in breast cancer may better inform tumor pathogenicity. G protein coupled receptor kinase 3 (GRK3) is a negative regulator of CXCR4 activity, and we show that GRK expression correlates with tumorigenicity, molecular subtype, and metastatic potential in human tumor microarray analysis. Using established human breast cancer cell lines and an immunocompetent in vivo mouse model, we further demonstrate that alterations in GRK3 expression levels in tumor cells directly affect migration and invasion in vitro and the establishment of distant metastasis in vivo. The effects of GRK3 modulation appear to be specific to chemokine-mediated migration behaviors without influencing tumor cell proliferation or survival. These data demonstrate that GRK3 dysregulation may play an important part in TNBC metastasis. 相似文献
985.
Participation of PI3K and ERK1/2 pathways are required for human brain vascular smooth muscle cell migration 总被引:2,自引:0,他引:2
Human brain vascular smooth muscle cell (HBVSMC) migration contributes to angiogenesis and several pathological processes in the brain. However, the molecular mechanism of angiogenesis, in which smooth muscle cell contributes, remains unclear. Our study investigates the role of vascular endothelial growth factor (VEGF) in the HBVSMC migration and elucidates the chemotactic signaling pathway mediating this action. We used the in vitro 'scratch' wound method to detect the HBVSMC migration. VEGF(165) (1-40ng/ml) induced the HBVSMC migration in a dose-dependent manner (P<0.05). VEGF(165) does not induce HBVSMC proliferation. Wortmannin, a specific phosphatidylinositol 3-kinase (PI3K) inhibitor, significantly inhibited serine/threonine kinase Akt/protein kinase B (PKB) phosphorylation and reduced HBVSMC migration into the wound edge following VEGF(165) stimulation (P<0.05). PD98059, an extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor, also significantly inhibited ERK1/2 phosphorylation and reduced the numbers of SMC migration. Parallel distance measurement showed that VEGF(165) induced HBVSMC migration significantly reduced due to inhibition of PI3K or ERK1/2 phosphorylation (P<0.05). Our results demonstrate that VEGF(165) could induce HBVSMC migration but not proliferation in vitro. Inhibiting Akt/PKB or ERK1/2 phosphorylation could reduce VEGF(165) induced HBVSMC migration. We provide the first evidence that activation of PI3K or ERK1/2 pathways are a crucial event in VEGF(165) mediated signal transduction leading to HBVSMC migration. 相似文献
986.
Chitosan sponges as tissue engineering scaffolds for bone formation 总被引:15,自引:0,他引:15
Seol YJ Lee JY Park YJ Lee YM Young-Ku Rhyu IC Lee SJ Han SB Chung CP 《Biotechnology letters》2004,26(13):1037-1041
Rat calvarial osteoblasts were grown in porous chitosan sponges fabricated by freeze drying. The prepared chitosan sponges had a porous structure with a 100-200 microm pore diameter, which allowed cell proliferation. Cell density, alkaline phosphatase activity and calcium deposition were monitored for up to 56 d culture. Cell numbers were 4 x 10(6) (day 1), 11 x 10(6) (day 28) and 12 x 10(6) (day 56) per g sponge. Calcium depositions were 9 (day 1), 40 (day 28) and 48 (day 56) microg per sponge. Histological results corroborated that bone formation within the sponges had occurred. These results show that chitosan sponges can be used as effective scaffolding materials for tissue engineered bone formation in vitro. 相似文献
987.
988.
Kyung SY Cho YK Kim YJ Park JW Jeong SH Lee JI Sung YM Lee SP 《The Korean journal of parasitology》2011,49(1):73-77
Paragonimiasis is an infectious disease caused by trematodes of the genus Paragonimus. This trematode can be treated successfully with praziquantel in more than 90% of the cases. Although praziquantel is generally well tolerated, anaphylactic reactions to this drug have been reported in a few cases. We report here a 46-year-old Korean female with paragonimiasis, presumed to be due to Paragonimus westermani, who displayed an allergic reaction to praziquantel and resistance to triclabendazole treatment. The patient was successfully treated with praziquantel following a rapid desensitization procedure. Desensitization to praziquantel could be considered when no alternative drugs are available. 相似文献
989.
Nam Jin-Sik Park Seo-Yeon Lee Seon-Ok Lee Hyo-Jeong Jang Hye-Lim Rhee Young Ha 《Molecular biology reports》2021,48(3):2173-2181
Molecular Biology Reports - The pawpaw tree has several beneficial effects. However, no studies have been conducted to address the mechanisms underlying the cytotoxic effects of pawpaw extracts... 相似文献
990.
Jun Won Kim Bung-Nyun Kim Jaewon Lee Chul Na Baik Seok Kee Kyung Joon Min Doug Hyun Han Johanna Inhyang Kim Young Sik Lee 《PloS one》2016,11(3)