American Association for the Advancement of Science (AAAS)
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Turning Blood into Brain: Cells Bearing Neuronal Antigens Generated in Vivo from Bone Marrow Bone marrow stem cells give rise to a variety of hematopoietic lineages and repopulate the blood throughout adult life. We show that, in a strain of mice incapable of developing cells of the myeloid and lymphoid lineages, transplanted adult bone marrow cells migrated into the brain and differentiated into cells that expressed neuron-specific antigens. These findings raise the possibility that bone marrow–derived cells may provide an alternative source of neurons in patients with neurodegenerative diseases or central nervous system injury.
American Association for the Advancement of Science (AAAS) - Tập 290 Số 5497 - Trang 1779-1782 - 2000
From Marrow to Brain: Expression of Neuronal Phenotypes in Adult Mice After intravascular delivery of genetically marked adult mouse bone marrow into lethally irradiated normal adult hosts, donor-derived cells expressing neuronal proteins (neuronal phenotypes) developed in the central nervous system. Flow cytometry revealed a population of donor-derived cells in the brain with characteristics distinct from bone marrow. Confocal microscopy of individual cells showed that hundreds of marrow-derived cells in brain sections expressed gene products typical of neurons (NeuN, 200-kilodalton neurofilament, and class III β-tubulin) and were able to activate the transcription factor cAMP response element–binding protein (CREB). The generation of neuronal phenotypes in the adult brain 1 to 6 months after an adult bone marrow transplant demonstrates a remarkable plasticity of adult tissues with potential clinical applications.
American Association for the Advancement of Science (AAAS) - Tập 290 Số 5497 - Trang 1775-1779 - 2000
Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration Bone marrow stromal cells (MSCs) have great potential as therapeutic agents. We report a method for inducing skeletal muscle lineage cells from human and rat general adherent MSCs with an efficiency of 89%. Induced cells differentiated into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. The induced population contained Pax7-positive cells that contributed to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. These MSCs represent a more ready supply of myogenic cells than do the rare myogenic stem cells normally found in muscle and bone marrow.
American Association for the Advancement of Science (AAAS) - Tập 309 Số 5732 - Trang 314-317 - 2005
The Action of Pteroylglutamic Conjugates on Man
American Association for the Advancement of Science (AAAS) - Tập 106 Số 2764 - Trang 619-621 - 1947
Direct Observation of Global Protein Motion in Hemoglobin and Myoglobin on Picosecond Time Scales Picosecond phase-grating spectroscopy is highly sensitive to density changes and provides a new holographic approach to the study of protein dynamics. Photodissociation of carbon monoxide from heme proteins induces a well-defined transition from a ligated to a deoxy structure that is important to hemoglobin and myoglobin functionality. Grating spectroscopy was used to observe protein-driven density waves on a picosecond time scale after carbon monoxide dissociation. This result demonstrates that global tertiary structure changes of proteins occur on an extremely fast time scale and provides new insight into the biomechanics of deterministic protein motion.
American Association for the Advancement of Science (AAAS) - Tập 251 Số 4997 - Trang 1051-1054 - 1991
Structure-based design of antiviral drug candidates targeting the SARS-CoV-2 main protease Promising antiviral protease inhibitors
With no vaccine or proven effective drug against the virus that causes coronavirus disease 2019 (COVID-19), scientists are racing to find clinical antiviral treatments. A promising drug target is the viral main protease M
pro
, which plays a key role in viral replication and transcription. Dai
et al.
designed two inhibitors, 11a and 11b, based on analyzing the structure of the M
pro
active site. Both strongly inhibited the activity of M
pro
and showed good antiviral activity in cell culture. Compound 11a had better pharmacokinetic properties and low toxicity when tested in mice and dogs, suggesting that this compound is a promising drug candidate.
Science
, this issue p.
1331
American Association for the Advancement of Science (AAAS) - Tập 368 Số 6497 - Trang 1331-1335 - 2020
Structure of the RNA-dependent RNA polymerase from COVID-19 virus The COVID-19 RNA-synthesizing machine
Many in the scientific community have mobilized to understand the virus that is causing the global coronavirus disease 2019 (COVID-19) pandemic. Gao
et al.
focused on a complex that plays a key role in the replication and transcription cycle of the virus. They used cryo–electron microscopy to determine a 2.9-angstrom-resolution structure of the RNA-dependent RNA polymerase nsp12, which catalyzes the synthesis of viral RNA, in complex with two cofactors, nsp7 and nsp8. nsp12 is a target for nucleotide analog antiviral inhibitors such as remdesivir, and the structure may provide a basis for designing new antiviral therapeutics.
Science
, this issue p.
779
American Association for the Advancement of Science (AAAS) - Tập 368 Số 6492 - Trang 779-782 - 2020
Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration River restoration guided by research
Human activities have altered the flow regimes of many of Earth's rivers, with negative impacts on biodiversity, water quality, and ecological processes. In a Review, Palmer and Ruhi explain how restoration designs now attempt to mimic ecologically important aspects of natural flow regimes, guided by insights into how variations in flow affect biota and ecosystem processes. To be successful, such efforts must go beyond accounting for flood pulses to restore natural flow variability and achieve hydrological connectivity between a river and its surroundings.
Science
, this issue p.
eaaw2087
American Association for the Advancement of Science (AAAS) - Tập 365 Số 6459 - 2019
Molecules in a Bose-Einstein Condensate State-selected rubidium-87 molecules were created at rest in a dilute Bose-Einstein condensate of rubidium-87 atoms with coherent free-bound stimulated Raman transitions. The transition rate exhibited a resonance line shape with an extremely narrow width as small as 1.5 kilohertz. The precise shape and position of the resonance are sensitive to the mean-field interactions between the molecules and the atomic condensate. As a result, we were able to measure the molecule-condensate interactions. This method allows molecular binding energies to be determined with unprecedented accuracy and is of interest as a mechanism for the generation of a molecular Bose-Einstein condensate.
American Association for the Advancement of Science (AAAS) - Tập 287 Số 5455 - Trang 1016-1019 - 2000
Filter Paper Electrophoresis of Avian Serum Proteins
American Association for the Advancement of Science (AAAS) - Tập 118 Số 3055 - Trang 86-89 - 1953
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