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101.
P Dutta G Courties Y Wei F Leuschner R Gorbatov CS Robbins Y Iwamoto B Thompson AL Carlson T Heidt MD Majmudar F Lasitschka M Etzrodt P Waterman MT Waring AT Chicoine AM van der Laan HW Niessen JJ Piek BB Rubin J Butany JR Stone HA Katus SA Murphy DA Morrow MS Sabatine C Vinegoni MA Moskowitz MJ Pittet P Libby CP Lin FK Swirski R Weissleder M Nahrendorf 《Nature》2012,487(7407):325-329
During progression of atherosclerosis, myeloid cells destabilize lipid-rich plaques in the arterial wall and cause their rupture, thus triggering myocardial infarction and stroke. Survivors of acute coronary syndromes have a high risk of recurrent events for unknown reasons. Here we show that the systemic response to ischaemic injury aggravates chronic atherosclerosis. After myocardial infarction or stroke, Apoe-/- mice developed larger atherosclerotic lesions with a more advanced morphology. This disease acceleration persisted over many weeks and was associated with markedly increased monocyte recruitment. Seeking the source of surplus monocytes in plaques, we found that myocardial infarction liberated haematopoietic stem and progenitor cells from bone marrow niches via sympathetic nervous system signalling. The progenitors then seeded the spleen, yielding a sustained boost in monocyte production. These observations provide new mechanistic insight into atherogenesis and provide a novel therapeutic opportunity to mitigate disease progression. 相似文献
102.
Massive gene decay in the leprosy bacillus 总被引:73,自引:0,他引:73
Cole ST Eiglmeier K Parkhill J James KD Thomson NR Wheeler PR Honoré N Garnier T Churcher C Harris D Mungall K Basham D Brown D Chillingworth T Connor R Davies RM Devlin K Duthoy S Feltwell T Fraser A Hamlin N Holroyd S Hornsby T Jagels K Lacroix C Maclean J Moule S Murphy L Oliver K Quail MA Rajandream MA Rutherford KM Rutter S Seeger K Simon S Simmonds M Skelton J Squares R Squares S Stevens K Taylor K Whitehead S Woodward JR Barrell BG 《Nature》2001,409(6823):1007-1011
Leprosy, a chronic human neurological disease, results from infection with the obligate intracellular pathogen Mycobacterium leprae, a close relative of the tubercle bacillus. Mycobacterium leprae has the longest doubling time of all known bacteria and has thwarted every effort at culture in the laboratory. Comparing the 3.27-megabase (Mb) genome sequence of an armadillo-derived Indian isolate of the leprosy bacillus with that of Mycobacterium tuberculosis (4.41 Mb) provides clear explanations for these properties and reveals an extreme case of reductive evolution. Less than half of the genome contains functional genes but pseudogenes, with intact counterparts in M. tuberculosis, abound. Genome downsizing and the current mosaic arrangement appear to have resulted from extensive recombination events between dispersed repetitive sequences. Gene deletion and decay have eliminated many important metabolic activities including siderophore production, part of the oxidative and most of the microaerophilic and anaerobic respiratory chains, and numerous catabolic systems and their regulatory circuits. 相似文献
103.
Identification of receptors for neuromedin U and its role in feeding 总被引:19,自引:0,他引:19
Howard AD Wang R Pong SS Mellin TN Strack A Guan XM Zeng Z Williams DL Feighner SD Nunes CN Murphy B Stair JN Yu H Jiang Q Clements MK Tan CP McKee KK Hreniuk DL McDonald TP Lynch KR Evans JF Austin CP Caskey CT Van der Ploeg LH Liu Q 《Nature》2000,406(6791):70-74
Neuromedin U (NMU) is a neuropeptide with potent activity on smooth muscle which was isolated first from porcine spinal cord and later from other species. It is widely distributed in the gut and central nervous system. Peripheral activities of NMU include stimulation of smooth muscle, increase of blood pressure, alteration of ion transport in the gut, control of local blood flow and regulation of adrenocortical function. An NMU receptor has not been molecularly identified. Here we show that the previously described orphan G-protein-coupled receptor FM-3 (ref. 15) and a newly discovered one (FM-4) are cognate receptors for NMU. FM-3, designated NMU1R, is abundantly expressed in peripheral tissues whereas FM-4, designated NMU2R, is expressed in specific regions of the brain. NMU is expressed in the ventromedial hypothalamus in the rat brain, and its level is significantly reduced following fasting. Intracerebroventricular administration of NMU markedly suppresses food intake in rats. These findings provide a molecular basis for the biochemical activities of NMU and may indicate that NMU is involved in the central control of feeding. 相似文献
104.
E. A. Mirand J. H. Groenewald G. M. Kenny G. P. Murphy 《Cellular and molecular life sciences : CMLS》1969,25(10):1104-1104
Zusammenfassung Der erythropoietische stimulierende Effekt von Depo-Testosteron-Zyklopentylpropionat in plethorischen Mäusen kann durch ein neues Antiandrogenpräparat (Cyproteronazetat — SH-714) verhindert werden. Dasselbe Präparat verhindert in plethorischen Mäusen ebenfalls die nach einer Standarddosis von Erythropoietin erwartete Blutneubildung. 相似文献
105.
106.
Quantification of modelling uncertainties in a large ensemble of climate change simulations 总被引:17,自引:0,他引:17
Murphy JM Sexton DM Barnett DN Jones GS Webb MJ Collins M Stainforth DA 《Nature》2004,430(7001):768-772
Comprehensive global climate models are the only tools that account for the complex set of processes which will determine future climate change at both a global and regional level. Planners are typically faced with a wide range of predicted changes from different models of unknown relative quality, owing to large but unquantified uncertainties in the modelling process. Here we report a systematic attempt to determine the range of climate changes consistent with these uncertainties, based on a 53-member ensemble of model versions constructed by varying model parameters. We estimate a probability density function for the sensitivity of climate to a doubling of atmospheric carbon dioxide levels, and obtain a 5-95 per cent probability range of 2.4-5.4 degrees C. Our probability density function is constrained by objective estimates of the relative reliability of different model versions, the choice of model parameters that are varied and their uncertainty ranges, specified on the basis of expert advice. Our ensemble produces a range of regional changes much wider than indicated by traditional methods based on scaling the response patterns of an individual simulation. 相似文献
107.
Roca AL Bar-Gal GK Eizirik E Helgen KM Maria R Springer MS O'Brien SJ Murphy WJ 《Nature》2004,429(6992):649-651
The highly endangered solenodons, endemic to Cuba (Solenodon cubanus) and Hispaniola (S. paradoxus), comprise the only two surviving species of West Indian insectivores. Combined gene sequences (13.9 kilobases) from S. paradoxus established that solenodons diverged from other eulipotyphlan insectivores 76 million years ago in the Cretaceous period, which is consistent with vicariance, though also compatible with dispersal. A sequence of 1.6 kilobases of mitochondrial DNA from S. cubanus indicated a deep divergence of 25 million years versus the congeneric S. paradoxus, which is consistent with vicariant origins as tectonic forces separated Cuba and Hispaniola. Efforts to prevent extinction of the two surviving solenodon species would conserve an entire lineage as old or older than many mammalian orders. 相似文献
108.
Monoenergetic beams of relativistic electrons from intense laser-plasma interactions 总被引:2,自引:0,他引:2
Mangles SP Murphy CD Najmudin Z Thomas AG Collier JL Dangor AE Divall EJ Foster PS Gallacher JG Hooker CJ Jaroszynski DA Langley AJ Mori WB Norreys PA Tsung FS Viskup R Walton BR Krushelnick K 《Nature》2004,431(7008):535-538
High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it propagates through a plasma, or through a direct interaction between the laser field and the electrons in the plasma. However, the electron beams produced from previous laser-plasma experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the electron beams produced from intense laser-plasma interactions, showing that--under particular plasma conditions--it is possible to generate beams of relativistic electrons with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the electron energy spectrum for plasma densities just above a threshold required for breaking of the plasma wave. These features were observed consistently in the electron spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic electron bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators. 相似文献
109.
Berger E Price PA Cenko SB Gal-Yam A Soderberg AM Kasliwal M Leonard DC Cameron PB Frail DA Kulkarni SR Murphy DC Krzeminski W Piran T Lee BL Roth KC Moon DS Fox DB Harrison FA Persson SE Schmidt BP Penprase BE Rich J Peterson BA Cowie LL 《Nature》2005,438(7070):988-990
Despite a rich phenomenology, gamma-ray bursts (GRBs) are divided into two classes based on their duration and spectral hardness--the long-soft and the short-hard bursts. The discovery of afterglow emission from long GRBs was a watershed event, pinpointing their origin to star-forming galaxies, and hence the death of massive stars, and indicating an energy release of about 10(51) erg. While theoretical arguments suggest that short GRBs are produced in the coalescence of binary compact objects (neutron stars or black holes), the progenitors, energetics and environments of these events remain elusive despite recent localizations. Here we report the discovery of the first radio afterglow from the short burst GRB 050724, which unambiguously associates it with an elliptical galaxy at a redshift z = 0.257. We show that the burst is powered by the same relativistic fireball mechanism as long GRBs, with the ejecta possibly collimated in jets, but that the total energy release is 10-1,000 times smaller. More importantly, the nature of the host galaxy demonstrates that short GRBs arise from an old (> 1 Gyr) stellar population, strengthening earlier suggestions and providing support for coalescing compact object binaries as the progenitors. 相似文献
110.
The proton/oxygen stoichiometry and the mechanism of the proton pumping respiratory complexes in the mitochondrial respiratory chain have been central issues in bioenergetics for several years. Recently, a number of disagreements about stoichiometry have been resolved, and H+/O ratios of 6 (refs 1-3) or perhaps 8 (refs 4 and 5) for succinate oxidation are now accepted. Suggestions that the stoichiometry in mitochondria is intrinsically variable ('slip' in the pumps) have been made but the evidence has been neither strong nor direct. We now show by direct measurement in steady-state conditions that the H+/O ratio (measured as the charge/O ratio) for isolated mitochondria respiring on succinate varies from 6 at low membrane potential to 2.5-3 at membrane potentials of about 170 mV. 相似文献