Conditional c-myb knockout in adult hematopoietic stem cells leads to loss of self-renewal due to impaired proliferation and accelerated differentiation.

abstract：:Spumaviruses, commonly called foamy viruses (FV), are complex retroviruses that establish lifelong persistent infections without any accompanying pathologies. In tissue culture, cells can be either lytically or latently infected, depending on cell type. Regulation of FV replication is controlled by two promoters: the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Meiering CD,Linial ML

更新日期：2002-11-12 00:00:00

abstract：:The late Pleistocene witnessed the extinction of 35 genera of North American mammals. The last appearance dates of 16 of these genera securely fall between 12,000 and 10,000 radiocarbon years ago (approximately 13,800-11,400 calendar years B.P.), although whether the absence of fossil occurrences for the remaining 19 ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Faith JT,Surovell TA

更新日期：2009-12-08 00:00:00

abstract：:Accumulative aggregation of mutant Huntingtin (Htt) is a primary neuropathological hallmark of Huntington's disease (HD). Currently, mechanistic understanding of the cytotoxicity of mutant Htt aggregates remains limited, and neuroprotective strategies combating mutant Htt-induced neurodegeneration are lacking. Here, w...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Zhu Y,Li C,Tao X,Brazill JM,Park J,Diaz-Perez Z,Zhai RG

更新日期：2019-09-17 00:00:00

abstract：:Optical recording of membrane potential permits spatially resolved measurement of electrical activity in subcellular regions of single cells, which would be inaccessible to electrodes, and imaging of spatiotemporal patterns of action potential propagation in excitable tissues, such as the brain or heart. However, the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yan P,Acker CD,Zhou WL,Lee P,Bollensdorff C,Negrean A,Lotti J,Sacconi L,Antic SD,Kohl P,Mansvelder HD,Pavone FS,Loew LM

更新日期：2012-12-11 00:00:00

abstract：:Vision loss affects >3 million Americans and many more people worldwide. Although predisposing genes have been identified their link to known environmental factors is unclear. In wild-type animals DNA alkylating agents induce photoreceptor apoptosis and severe retinal degeneration. Alkylation-induced retinal degenerat...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Meira LB,Moroski-Erkul CA,Green SL,Calvo JA,Bronson RT,Shah D,Samson LD

更新日期：2009-01-20 00:00:00

abstract：:The primary product of biological nitrogen fixation, ammonia, reversibly regulates nitrogenase activity in a variety of diazotrophs by a process called "NH4(+)-switch-off/on." Strong correlative evidence from work in Azospirillum lipoferum and Rhodospirillum rubrum indicates that this regulation involves both the inac...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fu H,Burris RH,Roberts GP

更新日期：1990-03-01 00:00:00

abstract：:GM54VA human cells transformed by simian virus 40 (SV40) were fused with peritoneal macrophages obtained from three different mouse strains. All 27 hybrid clones studied were positive for SV40 tumor antigen in 100% of their cells and contained human chromosome 17. Human chromosome 17 was the only human chromosome pres...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Croce CM

更新日期：1977-01-01 00:00:00

abstract：:Messenger RNA from rat liver was partially purified by chromatography on cellulose on the basis of its poly(A) content. Microgram amounts of this RNA stimulate protein synthesis manyfold in a heterologous cell-free system, derived from Krebs ascites cells supplemented with reticulocyte initiation factors. The messenge...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schutz G,Beato M,Feigelson P

更新日期：1973-04-01 00:00:00

abstract：:We have reexamined the balance between cell birth, cell maturation, and cell death in the thymus by labeling dividing thymocytes and their progeny in vivo with [3H]-thymidine, isolating clearly defined subpopulations by fluorescence-activated cell sorting, and determining the distribution of label by autoradiography. ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Egerton M,Scollay R,Shortman K

更新日期：1990-04-01 00:00:00

abstract：:Muscle plasminogen activators (PAs), such as urokinase-like PA and, to a lesser extent, tissue PA, increase dramatically after denervation induced by axotomy. The PA/plasmin system has also been implicated in degradation of specific components of the muscle fiber basement membrane after local activation of plasminogen...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hantaï D,Rao JS,Festoff BW

更新日期：1990-04-01 00:00:00

abstract：:Oxygen isotherms of human hemoglobin measured in distilled water and in solutions of sodium chloride in the concentration range from 0.02 to 3.0 M indicate that the oxygen affinity decreases up to about 1 M salt and then begins to increase. The isotherms obtained in the range from 0.02 to 0.6 M sodium chloride, at 37 ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Haire RN,Hedlund BE

更新日期：1977-10-01 00:00:00

abstract：:A Chinese hamster ovary cell (CHO) mutant (strain 58), defective in CDP-choline synthetase (cholinephosphate cytidylyltransferase; CTP:cholinephosphate cytidylyltransferase, EC 2.7.7.15), is temperature sensitive for growth and contains less than half of the normal amount of phosphatidylcholine under nonpermissive con...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Esko JD,Nishijima M,Raetz CR

更新日期：1982-03-01 00:00:00

abstract：:Rap phosphatases are a recently discovered family of protein aspartate phosphatases that dephosphorylate the Spo0F--P intermediate of the phosphorelay, thus preventing sporulation of Bacillus subtilis. They are regulators induced by physiological processes that are antithetical to sporulation. The RapA phosphatase is ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Perego M,Hoch JA

更新日期：1996-02-20 00:00:00

abstract：:A promising strategy for DNA sequencing exploits transposons to provide mobile sites for the binding of sequencing primers. For such a strategy to be maximally efficient, the location and orientation of the transposon must be readily determined and the insertion sites should be randomly distributed. We demonstrate an ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Strausbaugh LD,Bourke MT,Sommer MT,Coon ME,Berg CM

更新日期：1990-08-01 00:00:00

abstract：:DNA damage leads to a halt in proliferation owing to apoptosis or senescence, which prevents transmission of DNA alterations. This cellular response depends on the tumor suppressor p53 and functions as a powerful barrier to tumor development. Adult stem cells are resistant to DNA damage-induced apoptosis or senescence...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Insinga A,Cicalese A,Faretta M,Gallo B,Albano L,Ronzoni S,Furia L,Viale A,Pelicci PG

更新日期：2013-03-05 00:00:00

abstract：:Human-caused environmental changes are creating regional combinations of environmental conditions that, within the next 50 to 100 years, may fall outside the envelope within which many of the terrestrial plants of a region evolved. These environmental modifications might become a greater cause of global species extinc...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tilman D,Lehman C

更新日期：2001-05-08 00:00:00

abstract：:[3H]Forskolin bound to high- and low-affinity sites in the rat brain. The high-affinity site was discretely located, with highest densities in the striatum, nucleus accumbens, olfactory tubercule, substantia nigra, hippocampus, and the molecular layers of the cerebellum. This site did not correlate well with the distr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Poat JA,Cripps HE,Iversen LL

更新日期：1988-05-01 00:00:00

abstract：:The fundamental questions of how lubricant molecules organize into a layered structure under nanometers confinement and what is the interplay between layering and friction are still not well answered in the field of nanotribology. While the phase transition of lubricants during a squeeze-out process under compression ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Xu RG,Leng Y

更新日期：2018-06-26 00:00:00

abstract：:Familial multiple system tauopathy with presenile dementia (MSTD) is a neurodegenerative disease with an abundant filamentous tau protein pathology. It belongs to the group of familial frontotemporal dementias with Parkinsonism linked to chromosome 17 (FTDP-17), a major class of inherited dementing disorders whose gen...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Spillantini MG,Murrell JR,Goedert M,Farlow MR,Klug A,Ghetti B

更新日期：1998-06-23 00:00:00

abstract：:Scanning confocal fluorescence microscopy and multiphoton fluorescence microscopy were used to image the uptake of the protein lysozyme into individual ion exchange chromatography particles in a packed bed in real time. Self-sharpening concentration fronts penetrating into the particles were observed at low salt conce...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dziennik SR,Belcher EB,Barker GA,DeBergalis MJ,Fernandez SE,Lenhoff AM

更新日期：2003-01-21 00:00:00

abstract：:Ischemia of the myocardium and lower limbs is a common consequence of arterial disease and a major source of morbidity and mortality in modernized countries. Inducing neovascularization for the treatment of ischemia is an appealing therapeutic strategy for patients for whom traditional treatment modalities cannot be p...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Jang E,Albadawi H,Watkins MT,Edelman ER,Baker AB

更新日期：2012-01-31 00:00:00

abstract：:3H-Labeled complementary DNA specific for the envelope glycoprotein (env) gene of avian leukosis-sarcoma viruses was isolated by selective nucleic acid hybridization techniques, and used to analyze the expression of the endogenous provirus. The endogenous provirus in certain cell types termed chicken helper factor pos...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hayward WS,Hanafusa H

更新日期：1976-07-01 00:00:00

abstract：:BALB/c mice immunized with syngeneic methylcholanthrene-induced fibrosarcomas did not have antibodies against the unique tumor-specific transplantation antigens, even though they were capable of rejecting a lethal dose of tumor cells. Endogenous murine leukemia virus antigens expressed by certain of the tumors did, ho...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Brown JP,Klitzman JM,Hellström I,Nowinski RC,Hellström KE

更新日期：1978-02-01 00:00:00

abstract：:In vitro translation of cellular poly(A)+ RNA coupled with immunoprecipitation was developed as a technique for characterizing 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] receptors and assessing receptor mRNA activity. Cell-free translation of poly(A)+ RNA isolated from chicken intestine revealed two immunoprecipitable fo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mangelsdorf DJ,Pike JW,Haussler MR

更新日期：1987-01-01 00:00:00

abstract：:The soybean genome hosts a family of several hundred, relatively homogeneous copies of a large, copia/Ty1-like retroelement designated SIRE-1. A copy of this element has been recovered from a Glycine max genomic library. DNA sequence analysis of two SIRE-1 subclones revealed that SIRE-1 contains a long, uninterrupted,...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Laten HM,Majumdar A,Gaucher EA

更新日期：1998-06-09 00:00:00

abstract：:Particular major histocompatibility complex (MHC) class II alleles clearly contribute to T cell-mediated autoimmune type 1 diabetes (T1D) in both humans and nonobese diabetic (NOD) mice. However, studies in NOD mice indicate MHC class I-restricted T cell responses are also essential to T1D development. In humans, epid...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Marron MP,Graser RT,Chapman HD,Serreze DV

更新日期：2002-10-15 00:00:00

abstract：:We prove that the property of excision in algebraic K-theory is for a Q-algebra A equivalent to the H-unitality of the latter. Our excision theorem, in particular, implies Karoubi's conjecture on the equality of algebraic and topological K-theory groups of stable C*-algebras. It also allows us to identify the algebrai...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Suslin AA,Wodzicki M

更新日期：1990-12-15 00:00:00

abstract：:In mammalian brains, multielectrode recordings during sensory stimulation have revealed oscillations in different cortical areas that are transiently synchronous. These synchronizations have been hypothesized to support integration of sensory information or represent the operation of attentional mechanisms, but their ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Prechtl JC

更新日期：1994-12-20 00:00:00

abstract：:Patterns of interacting amino acids are so preserved within protein families that the sole analysis of evolutionary comutations can identify pairs of contacting residues. It is also known that evolution conserves functional dynamics, i.e., the concerted motion or displacement of large protein regions or domains. Is it...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Granata D,Ponzoni L,Micheletti C,Carnevale V

更新日期：2017-12-12 00:00:00

abstract：:Electron spin echo electron-nuclear double resonance (ESE-ENDOR) experiments performed on a broad radical electron paramagnetic resonance (EPR) signal observed in photosystem II particles depleted of Ca2+ indicate that this signal arises from the redox-active tyrosine YZ. The tyrosine EPR signal width is increased rel...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gilchrist ML Jr,Ball JA,Randall DW,Britt RD

更新日期：1995-10-10 00:00:00