排序方式: 共有160条查询结果,搜索用时 15 毫秒
71.
Ballif BC Rosenfeld JA Traylor R Theisen A Bader PI Ladda RL Sell SL Steinraths M Surti U McGuire M Williams S Farrell SA Filiano J Schnur RE Coffey LB Tervo RC Stroud T Marble M Netzloff M Hanson K Aylsworth AS Bamforth JS Babu D Niyazov DM Ravnan JB Schultz RA Lamb AN Torchia BS Bejjani BA Shaffer LG 《Human genetics》2012,131(1):145-156
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Christopher J. Gobler Dianna L. Berry O. Roger Anderson Amanda Burson Florian Koch Brooke S. Rodgers Lindsay K. Moore Jennifer A. Goleski Bassem Allam Paul Bowser Yingzhong Tang Robert Nuzzi 《Harmful algae》2008,7(3):293
We report on the emergence of Cochlodinium polykrikoides blooms in the Peconic Estuary and Shinnecock Bay, NY, USA, during 2002–2006. Blooms occurred during late summer when temperatures and salinities ranged from 20 to 25 °C and 22 to 30 ppt, respectively. Bloom patches achieved cell densities exceeding 105 ml−1 and chlorophyll a levels exceeding 100 μg l−1, while background bloom densities were typically 103–104 cells ml−1. Light, scanning electron and ultrathin-section transmission electron microscopy suggested that cells isolated from blooms displayed characteristics of C. polykrikoides and provide the first clear documentation of the fine structure for this species. Sequencing of a hypervariable region of the large subunit rDNA confirmed this finding, displaying 100% similarity to other North American C. polykrikoides strains, but a lower similarity to strains from Southeast Asia (88–90%). Bioassay experiments demonstrated that 24 h exposure to bloom waters (>5 × 104 cells ml−1) killed 100% of multiple fish species (1-week-old Cyprinodon variegates, adult Fundulus majalis, adult Menidia menidia) and 80% of adult Fundulus heteroclitus. Microscopic evaluation of the gills of moribund fish revealed epithelial proliferation with focal areas of fusion of gill lamellae, suggesting impairment of gill function (e.g. respiration, nitrogen excretion, ion balance). Lower fish mortality was observed at intermediate C. polykrikoides densities (103–104 cells ml−1), while fish survived for 48 h at cell densities below 1 × 103 cells ml−1. The inability of frozen and thawed-, or filtered (0.2 μm)-bloom water to cause fish mortality suggested that the thick polysaccharide layer associated with cell membranes and/or a toxin principle within this layer may be responsible for fish mortality. Juvenile bay scallops (Argopecten irradians) and American oysters (Crassostrea virginica) experienced elevated mortality compared to control treatments during a 9-day exposure to bloom water (5 × 104 cells ml−1). Surviving scallops exposed to bloom water also experienced significantly reduced growth rates. Moribund shellfish displayed hyperplasia, hemorrhaging, squamation, and apoptosis in gill and digestive tissues with gill inflammation specifically associated with areas containing C. polykrikoides cells. In summary, our results indicate C. polykrikoides blooms have become annual events on eastern Long Island and that bloom waters are capable of causing rapid mortality in multiple species of finfish and shellfish. 相似文献
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Leivar P Monte E Al-Sady B Carle C Storer A Alonso JM Ecker JR Quail PH 《The Plant cell》2008,20(2):337-352
We show that a previously uncharacterized Arabidopsis thaliana basic helix-loop-helix (bHLH) phytochrome interacting factor (PIF), designated PIF7, interacts specifically with the far-red light-absorbing Pfr form of phyB through a conserved domain called the active phyB binding motif. Similar to PIF3, upon light exposure, PIF7 rapidly migrates to intranuclear speckles, where it colocalizes with phyB. However, in striking contrast to PIF3, this process is not accompanied by detectable light-induced phosphorylation or degradation of PIF7, suggesting that the consequences of interaction with photoactivated phyB may differ among PIFs. Nevertheless, PIF7 acts similarly to PIF3 in prolonged red light as a weak negative regulator of phyB-mediated seedling deetiolation. Examination of pif3, pif4, and pif7 double mutant combinations shows that their moderate hypersensitivity to extended red light is additive. We provide evidence that the mechanism by which these PIFs operate on the phyB signaling pathway under prolonged red light is through maintaining low phyB protein levels, in an additive or synergistic manner, via a process likely involving the proteasome pathway. These data suggest that the role of these phyB-interacting bHLH factors in modulating seedling deetiolation in prolonged red light may not be as phy-activated signaling intermediates, as proposed previously, but as direct modulators of the abundance of the photoreceptor. 相似文献
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Therapeutic efficacy of anti-ErbB2 immunoliposomes targeted by a phage antibody selected for cellular endocytosis 总被引:8,自引:0,他引:8
Nielsen UB Kirpotin DB Pickering EM Hong K Park JW Refaat Shalaby M Shao Y Benz CC Marks JD 《Biochimica et biophysica acta》2002,1591(1-3):109-118
Many targeted cancer therapies require endocytosis of the targeting molecule and delivery of the therapeutic agent to the interior of the tumor cell. To generate single chain Fv (scFv) antibodies capable of triggering receptor-mediated endocytosis, we previously developed a method to directly select phage antibodies for internalization by recovering infectious phage from the cytoplasm of the target cell. Using this methodology, we reported the selection of a panel of scFv that were internalized into breast cancer cells from a nonimmune phage library. For this work, an immunotherapeutic was generated from one of these scFv (F5), which bound to ErbB2 (HER2/neu). The F5 scFv was reengineered with a C-terminal cysteine, expressed at high levels in Escherichia coli, and coupled to sterically stabilized liposomes. F5 anti-ErbB2 immunoliposomes were immunoreactive as determined by surface plasmon resonance (SPR) and were avidly internalized by ErbB2-expressing tumor cell lines in proportion to the levels of ErbB2 expression. F5-scFv targeted liposomes containing doxorubicin had antitumor activity and produced significant reduction in tumor size in xenografted mice compared to nontargeted liposomes containing doxorubicin. This strategy should be applicable to generate immunotherapeutics for other malignancies by selecting phage antibodies for internalization into other tumor types and using the scFv to target liposomes or other nanoparticles. 相似文献
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Xiong J Fan S Meng Q Schramm L Wang C Bouzahza B Zhou J Zafonte B Goldberg ID Haddad BR Pestell RG Rosen EM 《Molecular and cellular biology》2003,23(23):8668-8690
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Mechri Sondes Bouacem Khelifa Zaraî Jaouadi Nadia Rekik Hatem Ben Elhoul Mouna Omrane Benmrad Maroua Hacene Hocine Bejar Samir Bouanane-Darenfed Amel Jaouadi Bassem 《Extremophiles : life under extreme conditions》2019,23(6):687-706
Extremophiles - A thermostable extracellular alkaline protease (called SAPA) was produced (4600 U/mL) by Anoxybacillus kamchatkensis M1V, purified to homogeneity, and biochemically... 相似文献
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Hindsight regulates photoreceptor axon targeting through transcriptional control of jitterbug/Filamin and multiple genes involved in axon guidance in Drosophila 下载免费PDF全文
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The behaviour of all animals is governed by the connectivity of neural circuits in the brain. Neurodevelopmental and neurodegenerative diseases, as well as traumatic injuries to the nervous system, can alter or disrupt the normal connectivity of the brain and result in disability. In this review, we highlight the contributions of the genetic model organism Drosophila melanogaster to our understanding of neural connectivity in health and disease. In this context we also discuss the research areas in which we believe the fruitfly is likely to be a useful model system in the future. 相似文献
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During neurogenesis in Drosophila, ectodermal cells are endowed with the capacity to become neuronal precursors. Following their selection, these cells initiate neuronal lineage development and differentiation. The processes of neuronal precursor specification and neuronal lineage development require the activities of several groups of genes functioning in a complex, hierarchical regulatory network. Whereas the proneural genes promote neurogenic potential, neurogenic genes restrict the acquisition of this identity to a subset of ectodermal cells. Following their selection, these cells express the pan neural neuronal precursor genes and a set of neuronal lineage identity genes. While lineage identity genes allow the various lineages to acquire specific identities, neuronal precursor genes presumably regulate functional and developmental characteristics common to all neuronal precursor cells. © 1996 Wiley-Liss, Inc. 相似文献