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991.
Emmanouil Fokas Gerhard Kraft Hanxiang An Rita Engenhart-Cabillic 《生物化学与生物物理学报:癌评论》2009,1796(2):216-229
High-energy protons and carbon ions exhibit an inverse dose profile allowing for increased energy deposition with penetration depth. Additionally, heavier ions like carbon beams have the advantage of a markedly increased biological effectiveness characterized by enhanced ionization density in the individual tracks of the heavy particles, where DNA damage becomes clustered and therefore more difficult to repair, but is restricted to the end of their range. These superior biophysical and biological profiles of particle beams over conventional radiotherapy permit more precise dose localization and make them highly attractive for treating anatomically complex and radioresistant malignant tumors but without increasing the severe side effects in the normal tissue. More than half a century since Wilson proposed their use in cancer therapy, the effects of particle beams have been extensively investigated and the biological complexity of particle beam irradiation begins to unfold itself. The goal of this review is to provide an as comprehensive and up-to-date summary as possible of the different radiobiological aspects of particle beams for effective application in cancer treatment. 相似文献
992.
Tiago Rodrigues Rita C. Guedes Daniel J.V.A. dos Santos Marta Carrasco Jiri Gut Philip J. Rosenthal Rui Moreira Francisca Lopes 《Bioorganic & medicinal chemistry letters》2009,19(13):3476-3480
(1H-Pyridin-4-ylidene)amines containing lipophilic side chains at the imine nitrogen atom were prepared as potential clopidol isosteres in the development of antimalarials. Their antiplasmodial activity was evaluated in vitro against the Plasmodium falciparum W2 (chloroquine-resistant) and FCR3 (atovaquone-resistant) strains. The most active of these derivatives, 4m, had an IC50 of 1 μM against W2 and 3 μM against FCR3. Molecular modeling studies suggest that (1H-pyridin-4-ylidene)amines may bind to the ubiquinol oxidation Qo site of cytochrome bc1. 相似文献
993.
994.
Jing Yao Yanling Liu Junaid Husain Rita Lo Anuradha Palaparti Janet Henderson Stefano Stifani 《Development, growth & differentiation》1998,40(2):133-146
The Drosophila protein Groucho is involved in the regulation of cell-determination events during insect neurogenesis and segmentation. A group of mammalian proteins, referred to as transducin-like Enhancer of split (TLE) 1 through 4, share with Groucho identical structures and molecular properties. The aim was to determine whether individual TLE proteins participate in the regulation of cell determination in mammals like their Drosophila counterpart. It is here reported that TLE family members are expressed in combinatorial ways during the in vitro differentiation of mouse P19 embryonic carcinoma cells (a model for neural determination) and rat CFK2 cells (a model for chondrocytic determination). TLE1 is up-regulated and TLE2 and TLE4 are down-regulated to different extents during early stages of differentiation. In contrast, later stages correlate with up-regulation of TLE2 and TLE4, and decreased expression of TLE1. Individual TLE proteins are also expressed in combinatorial as well as complementary patterns during the development of the cerebral cortex and spinal cord of mouse embryos. In particular, TLE1 is robustly expressed in both neural progenitor cells and postmitotic neurons of the outer layers of the cortical plate, whereas TLE4 expression marks preferentially postmitotic neurons of the inner layers. Taken together, these results strongly suggest non-redundant roles for individual TLE proteins during both cell-determination and cell-differentiation events. 相似文献
995.
996.
Christina B. Karsten Falk F. R. Buettner Samanta Cajic Inga Nehlmeier Berit Neumann Antonina Klippert Ulrike Sauermann Udo Reichl Rita Gerardy-Schahn Erdmann Rapp Christiane Stahl-Hennig Stefan P?hlmann 《Journal of virology》2015,89(22):11727-11733
Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelope (Env) proteins are extensively decorated with N-glycans, predominantly of the high-mannose type. However, it is unclear how high-mannose N-glycans on Env impact viral spread. We show that exclusive modification of SIV Env with these N-glycans reduces viral infectivity and abrogates mucosal transmission, despite increasing viral capture by immune cell lectins. Thus, high-mannose N-glycans have opposed effects on SIV infectivity and lectin reactivity, and a balance might be required for efficient mucosal transmission. 相似文献
997.
Srdjan M. Vlajkovic Kyu-Hyun Lee Ann Chi Yan Wong Cindy X. Guo Rita Gupta Gary D. Housley Peter R. Thorne 《Purinergic signalling》2010,6(2):273-281
Hearing loss from noise exposure is a leading occupational disease, with up to 5% of the population at risk world-wide. Here,
we present a novel purine-based pharmacological intervention that can ameliorate noise-induced cochlear injury. Wistar rats
were exposed to narrow-band noise (8–12 kHz, 110 dB SPL, 2–24 h) to induce cochlear damage and permanent hearing loss. The
selective adenosine A1 receptor agonist, adenosine amine congener (ADAC), was administered intraperitoneally (100 μg/kg/day) at time intervals after
noise exposure. Hearing thresholds were assessed using auditory brainstem responses and the hair cell loss was evaluated by
quantitative histology. Free radical damage in the organ of Corti was assessed using nitrotyrosine immunohistochemistry. The
treatment with ADAC after noise exposure led to a significantly greater recovery of hearing thresholds compared with controls.
These results were upheld by increased survival of sensory hair cells and reduced nitrotyrosine immunoreactivity in ADAC-treated
cochlea. We propose that ADAC could be a valuable treatment for noise-induced cochlear injury in instances of both acute and
extended noise exposures. 相似文献
998.
Qiang Chang Rita J. Balice-Gordon 《BioEssays : news and reviews in molecular, cellular and developmental biology》1997,19(4):271-275
During late embryonic and early postnatal development, synaptic connections are extensively modified so that some functional connections are weakened and eliminated from a neural circuit while others are strengthened and maintained. The mechanisms that underlie synapse elimination are beginning to be understood from studies of the neuromuscular junction. A recent paper(1) provides some intriguing insights into the role proteases may play in the developmental disassembly of neuromuscular synapses. 相似文献
1000.
Joana D. Amaral Ricardo J. S. Viana Rita M. Ramalho Clifford J. Steer Cec��lia M. P. Rodrigues 《Journal of lipid research》2009,50(9):1721-1734
Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer''s, Parkinson''s, and Huntington''s diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases. 相似文献